Papers for Tuesday, Dec 05 2023

We present Keck Cosmic Web Imager (KCWI) Ly$\alpha$ integral field spectroscopy of the fields surrounding 14 Damped Ly$\alpha$ absorbers (DLAs) at $z \approx 2$. Of these 14 DLAs, 9 have high metallicities ([M/H]$~> -0.3$), and 4 of those 9 feature a CO-emitting galaxy at an impact parameter $\lesssim 30$ kpc. Our search reaches median Ly$\alpha$ line flux sensitivities of $\sim 2 \times 10^{-17}$ erg s$^{-1}$ cm$^{-2}$ over apertures of $\sim6$ kpc and out to impact parameters of $\sim50$ kpc. We recover the Ly$\alpha$ flux of three known Ly$\alpha$-emitting H I-selected galaxies in our sample. In addition, we find two Ly$\alpha$ emitters at impact parameters of $\approx 50-70$ kpc from the high metallicity DLA at $z \approx 1.96$ toward QSO B0551-366. This field also contains a massive CO-emitting galaxy at an impact parameter of $\approx 15$ kpc. Apart from the field with QSO B0551-366, we do not detect significant Ly$\alpha$ emission in any of the remaining 8 high-metallicity DLA fields. Considering the depth of our observations and our ability to recover previously known Ly$\alpha$ emitters, we conclude that H I-selected galaxies associated with high-metallicity DLAs at $z \approx 2$ are dusty, and therefore might feature low Ly$\alpha$ escape fractions. Our results indicate that complementary approaches -- using Ly$\alpha$, CO, H$\alpha$, and [C II] 158$\mu$m emission -- are necessary to identify the wide range of galaxy types associated with $z \approx 2$ DLAs.

We use the POLARIS radiative transfer code to produce simulated circular polarization Zeeman emission maps of the CN $J = 1 - 0$ molecular line transition for two types of protostellar envelope magnetohydrodynamic simulations. Our first model is a low mass disk envelope system (box length $L = 200\text{ au}$), and our second model is the envelope of a massive protostar ($L = 10^4\text{ au}$) with a protostellar wind and a CN enhanced outflow shell. We compute the velocity-integrated Stokes $I$ and $V$, as well as the implied $V/I$ polarization percentage, for each detector pixel location in our simulated emission maps. Our results show that both types of protostellar environment are in principle accessible with current circular polarization instruments, with each containing swaths of envelope area that yield percentage polarizations that exceed the 1.8\% nominal sensitivity limit for circular polarization experiments with the Atacama Large Millimeter/submillimeter Array (ALMA). In both systems, high polarization ($\gtrsim$1.8\%) pixels tend to lie at an intermediate distance away from the central star and where the line-center opacity of the CN emission is moderately optically thin ($\tau_{LC} \sim 0.1-1$). Furthermore, our computed $V/I$ values scale roughly with the density weighted mean line-of-sight magnetic field strength, indicating that Zeeman observations can effectively diagnose the strength of envelope-scale magnetic fields. We also find that pixels with large $V/I$ are preferentially co-located where the absolute value of the velocity-integrated $V$ is also large, suggesting that locations with favorable percentage polarization are also favorable in terms of raw signal.

The Aether-Scalar-Tensor (AeST) theory is an extension of General Relativity (GR) which can support Modified Newtonian Dynamics (MOND) behaviour in its static weak-field limit, and cosmological evolution resembling $\Lambda$CDM. We consider static spherically symmetric weak-field solutions in this theory and show that the resulting equations can be reduced to a single equation for the gravitational potential. The reduced equation has apparent isolated singularities when the derivative of the potential passes through zero and we show how these are removed by evolving, instead, the canonical momentum of the corresponding Hamiltonian system that we find. We construct solutions in three cases: (i) vacuum outside a bounded spherical object, (ii) within an extended prescribed source, and (iii) isothermal gas in hydrostatic equilibrium, serving as a simplified model for galaxy clusters. We show that the oscillatory regime that follows the Newtonian and MOND regimes, obtained in previous works in the vacuum case, also persists for isothermal spheres, and we show that the gas density profiles in AeST may become more compressed than their Newtonian or MOND counterparts. We construct the Radial Acceleration Relation (RAR) in AeST for isothermal spheres and find that it can display a peak, an enhancement with respect to the MOND RAR, at an acceleration range determined by the value of the AeST weak-field mass parameter, the mass of the system and the boundary value of the gravitational potential. For lower accelerations, the AeST RAR drops below the MOND expectation, as if there is a negative mass density. Similar observational features of the galaxy cluster RAR have been reported. This illustrates the potential of AeST to address the shortcomings of MOND in galaxy clusters, but a full quantitative comparison with observations will require going beyond the isothermal case.

The role of unresolved structures ("mini-halos") in determining the consumption of ionizing photons during cosmic reionization remains an unsolved problem in modeling cosmic reionization, despite recent extensive studies with small-box high-resolution simulations by Park et al. and Chan et al., because the small-box studies are not able to fully sample all environments. In this paper these simulations are combined with large-box simulations from the "Cosmic Reionization On Computers" (CROC) project, allowing one to account for the full range of environments and to produce an estimate for the number of recombinations per hydrogen atom that are missed in large-scale simulations like CROC or Thesan. I find that recombinations in unresolved mini-halos are completely negligible compared to recombinations produced in large-scale cosmic structures and inside more massive, fully resolved halos. Since both Park et al. and Chan et al. studies have severe limitations, the conclusions of this paper may need to be verified with more representative sets of small-box high-resolution simulations.

In this work, we present an optical survey of mm-sized meteoroids using the Canadian Automated Meteor Observatory's (CAMO) mirror tracking system. The system tracks meteors to magnitude +7.5 through an image-intensified telescopic system which has a spatial accuracy of $\sim$1 m and a temporal resolution of 10 ms. We analyze 41 meteors from 13 showers with known parent bodies, recorded between 2016 and 2022. We fit a numerical ablation and fragmentation model to our data which models meteoroid fragmentation as erosion into 10 - 500 $\mu$m constituent grains and uses the observed wake as a hard constraint on the model parameters. We measure average bulk meteoroid densities which are consistent with in situ measurements: 602 $\pm$ 155 kg m$^{-3}$ for Jupiter-family and 345 $\pm$ 48 kg m$^{-3}$ for Halley-type showers. The Geminids had the highest measured bulk density of 1387 $\pm$ 240 kg m$^{-3}$, consistent with carbonaceous material. We fail to reproduce the high bulk density ($>3000$ kg m$^{-3}$) for Jupiter-family meteoroids previously reported in the literature derived using fragmentation models on data sets with fewer observational constraints. We also provide estimates of the meteoroid grain sizes, grain mass distributions, and energy necessary to trigger the erosion for meteoroids in the analyzed showers.

The SPT0311-58 system resides in a massive dark matter halo at z ~ 6.9. It hosts two dusty galaxies (E and W) with a combined star formation rate (SFR) of ~3500 Msun/yr. Its surrounding field exhibits an overdensity of sub-mm sources, making it a candidate proto-cluster. We use spatially-resolved spectroscopy provided by the JWST/NIRSpec Integral Field Unit (IFU) to probe a field of view (FoV) ~ 17 x 17 kpc^2 around this object, with a spatial resolution ~ 0.5 kpc. These observations have revealed ten new galaxies at z ~ 6.9, characterised by dynamical masses spanning from ~10^9 to 10^10 Msun and a range in radial velocities of ~ 1500 km/s, in addition to the already known E and W galaxies. The implied large number density, and the wide spread in velocities, indicate that SPT0311-58 is at the core of a proto-cluster, immersed in a very massive dark matter halo of ~ 6 x 10^12 Msun. We study the dynamical stage of the system and find that it likely is not fully virialized, although most of the galaxies are gravitationally bound to the halo. The galaxies exhibit a great diversity of properties. We derive their ongoing Halpha-based unobscured SFR, and find that its contribution to the total SF varies significantly across the galaxies in the system. Their ionization conditions range from those typical of galaxies at similar redshift recently studied with JWST to those found in lower redshift objects. The metallicity spans more than 0.8 dex across the FoV, reaching in some cases nearly solar values. The detailed IFU spectroscopy of the E galaxy reveals that it is actively assembling its stellar mass, showing a metallicity gradient (~ 0.1 dex/kpc) that can be explained by accretion of low metallicity gas from the intergalactic medium. The kinematic maps indicate departures from regular rotation, high turbulence, and a possible pre-collision minor merger. (Abridged)

Gas accretion by a galaxy's central super massive black hole (SMBH) and the resultant energetic feedback by the accreting active galactic nucleus (AGN) on the gas in and around a galaxy, are two tightly intertwined but competing processes that play a crucial role in the evolution of galaxies. Observations of galaxy clusters have shown how the plasma jets emitted by the AGN heat the intra-cluster medium (ICM), preventing cooling of the cluster gas and thereby the infall of this gas onto the central galaxy. On the other hand, outflows of multi-phase gas, driven by the jets, can cool as they rise into the ICM, leading to filaments of colder gas. The fate of this cold gas is unclear, but it has been suggested it plays a role in feeding the central SMBH. We present the results of re-processed CO(2-1) ALMA observations of the cold molecular gas in the central regions of NGC 1275, the central galaxy of the Perseus cluster and hosting the radio-loud AGN 3C 84 (Perseus A). These data show, for the first time, in detail how kpc-sized cold gas filaments resulting from jet-induced cooling of cluster gas are flowing towards the galaxy centre and how they feed the circumnuclear accretion disc (100 pc diameter) of the SMBH. Thus, cooled gas can, in this way, play a role in feeding the AGN. These results complete our view of the feedback loop of how an AGN can impact on its surroundings and how the effects from this impact maintain the AGN activity.

We introduce the MUSE gAlaxy Groups in COSMOS (MAGIC) survey built to study the impact of environment on galaxy evolution over the last 8 Gyr. It consists of 17 MUSE fields targeting 14 massive structures at intermediate redshift ($0.3<z<0.8$) in the COSMOS area. We securely measure redshifts for 1419 sources and identify 76 galaxy pairs and 67 groups of at least 3 members using a friends-of-friends algorithm. The environment of galaxies is quantified from group properties, as well as from global and local density estimators, inferred from galaxy number density and dynamics within groups. The MAGIC survey increases the number of objects with a secure spectroscopic redshift over its footprint by a factor of $\sim 5$. Most of the new redshifts have apparent magnitudes in the $z^{++}$ band $z_{app}^{++}>21.5$. The spectroscopic redshift completeness is high: in the redshift range of [OII] emitters ($0.25 \le z < 1.5$), where most of the groups are found, it globally reaches a maximum of 80% down to $z_{app}^{++}=25.9$, and it locally decreases from $\sim 100$% to $\sim50$% in magnitude bins from $z_{app}^{++}=23-24$ to $z_{app}^{++}=25.5$. We find that the fraction of quiescent galaxies increases with local density and with the time spent in groups. A morphological dichotomy is also found between bulge-dominated quiescent and disk-dominated star-forming galaxies. As environment gets denser, the peak of the stellar mass distribution shifts towards $M_*>10^{10} M_\odot, the fraction of galaxies with $M_*<10^9 M_\odot$ decreasing significantly, even for star-forming galaxies. We also highlight peculiar features such as close groups, extended nebulae, and a gravitational arc. Our results suggest that galaxies are pre-processed in groups of increasing mass before entering rich groups and clusters. We publicly release two catalogs containing the properties of galaxies and groups, respectively.

We used 5487 star-forming galaxies at redshift z~0.63 extracted from the VIPERS and 143774 comparison galaxies in the local Universe from the GSWLC catalog. We employed two families of methods: parametric and non-parametric. In the former approaches, we compared the FMR projections plagued by observational biases on differently constructed control samples at various redshifts. Then, the metallicity difference between different redshifts in M*-SFR bins. In the latter approach, we related the metallicity and the normalized sSFR. The methodologies implemented to construct fair, complete samples for studying the MZR and the FMR produced consistent results showing a small, but still statistically significant evolution of both relations up to z~0.63. In particular, we observed a systematic trend where the median metallicity of the sample at z=0.63 is lower than that of the local sample at the same M* and SFR. The average difference in the metallicity of the low and intermediate redshifts is approximately 1.8 times the metallicity standard deviation of the median, of the intermediate redshift sample, in M*-SFR bins. We confirmed this result using the Kolmogorov-Smirnov test. When we applied the M*-completeness criterion to catalogs, the metallicity difference in redshifts decreased to approximately 0.96 times the metallicity standard deviation of the median, thus not statistically significant. This result may be dominated by the limited parameter space, being the lower M* galaxies where the difference is larger out from the analysis. A careful reading of the results, and their underlying selection criteria, are crucial in studies of the mass-metallicity and FMRs.

Strong gravitational lensing of quasars has the potential to unlock the poorly understood physics of these fascinating objects, as well as serve as a probe of the lensing mass distribution and of cosmological parameters. In particular, gravitational microlensing by compact bodies in the lensing galaxy can enable mapping of quasar structure to $\lt 10^{-6}$ arcsec scales. Some of this potential has been realized over the past few decades, however the upcoming era of large sky surveys promises to bring this to full fruition. Here we review the theoretical framework of this field, describe the prominent current methods for parameter inference from quasar microlensing data across different observing modalities, and discuss the constraints so far derived on the geometry and physics of quasar inner structure. We also review the application of strong lensing and microlensing to constraining the granularity of the lens potential, i.e. the contribution of the baryonic and dark matter components, and the local mass distribution in the lens, i.e. the stellar mass function. Finally, we discuss the future of the field, including the new possibilities that will be opened by the next generation of large surveys and by new analysis methods now being developed.

We present new spatially resolved astrometry and photometry of the CD-27 11535 system, a member of the $\beta$ Pictoris moving group consisting of two resolved K-type stars on a $\sim$20-year orbit. We fit an orbit to relative astrometry measured from NIRC2, GPI, and archival NaCo images, in addition to literature measurements. However, the total mass inferred from this orbit is significantly discrepant from that inferred from stellar evolutionary models using the luminosity of the two stars. We explore two hypotheses that could explain this discrepant mass sum; a discrepant parallax measurement from Gaia due to variability, and the presence of an additional unresolved companion to one of the two components. We find that the $\sim$20-year orbit could not bias the parallax measurement, but that variability of the components could produce a large amplitude astrometric motion, an effect which cannot be quantified exactly without the individual Gaia measurements. The discrepancy could also be explained by an additional star in the system. We jointly fit the astrometric and photometric measurements of the system to test different binary and triple architectures for the system. Depending on the set of evolutionary models used, we find an improved goodness of fit for a triple system architecture that includes a low-mass ($M=0.177\pm0.055$\,$M_{\odot}$) companion to the primary star. Further studies of this system will be required in order to resolve this discrepancy, either by refining the parallax measurement with a more complex treatment of variability-induced astrometric motion, or by detecting a third companion.

The astrophysical formation channels of binary black hole systems predict correlations between their mass, spin, and redshift distributions, which can be probed with gravitational-wave observations. Population-level analysis of the latest LIGO-Virgo-KAGRA catalog of binary black hole mergers has identified evidence for such correlations assuming linear evolution of the mean and width of the effective spin distribution as a function of the binary mass ratio and merger redshift. However, the complex astrophysical processes at play in compact binary formation do not necessarily predict linear relationships between the distributions of these parameters. In this work, we relax the assumption of linearity and instead search for correlations using a more flexible cubic spline model. Our results suggest a nonlinear correlation between the width of the effective spin distribution and redshift. We also show that the LIGO-Virgo-Kagra collaborations may find convincing Bayesian evidence for nonlinear correlations by the end of the fourth observing run, O4. This highlights the valuable role of flexible models in population analyses of compact-object binaries in the era of growing catalogs.

In this paper, we introduce a novel data augmentation methodology based on Conditional Progressive Generative Adversarial Networks (CPGAN) to generate diverse black hole (BH) images, accounting for variations in spin and electron temperature prescriptions. These generated images are valuable resources for training deep learning algorithms to accurately estimate black hole parameters from observational data. Our model can generate BH images for any spin value within the range of [-1, 1], given an electron temperature distribution. To validate the effectiveness of our approach, we employ a convolutional neural network to predict the BH spin using both the GRMHD images and the images generated by our proposed model. Our results demonstrate a significant performance improvement when training is conducted with the augmented dataset while testing is performed using GRMHD simulated data, as indicated by the high R2 score. Consequently, we propose that GANs can be employed as cost effective models for black hole image generation and reliably augment training datasets for other parameterization algorithms.

We present constraints on the extended Starobinsky and Weyl gravity model of inflation using updated available observational data. The data includes cosmic microwave background (CMB) anisotropy measurements from Planck and BICEP/Keck 2018 (BK18), as well as large-scale structure data encompassing cosmic shear and galaxy autocorrelation and cross-correlation functions measurements from Dark Energy Survey (DES), baryonic acoustic oscillation (BAO) measurements from 6dF, MGS and BOSS, and distance measurements from supernovae type Ia from Pantheon+ samples. By introducing a single additional parameter, each model extends the Starobinsky model to encompass larger region of parameter space while remaining consistent with all observational data. Specifically for higher number of $e$-folding, these models extend viable range of tensor-to-scalar ratio ($r$) to very small value $r<0.001$ in contrast to the original $R^2$ Starobinsky model. In addition, our results continue to emphasize the tension in $H_0$ and $S_8$ between early-time CMB measurements and late-time large-scale structure observations.

Switchbacks (SBs) are localized structures in the solar wind containing deflections of the magnetic field direction relative to the background solar wind magnetic field. The amplitudes of the magnetic field deflection angles for different SBs vary from ~40 to ~160-170 degrees. Alignment of the perturbations of the magnetic field and the bulk solar wind velocity is observed inside SBs and causes spiky enhancements of the radial bulk velocity inside SBs. We have investigated the deviations of SB perturbations from Alfv\'enicity by evaluating the distribution of the parameter defined as the ratio of the parallel to $\Delta\vec{B}$ component of $\Delta\vec{V}$ to $\Delta\vec{V}_A = \Delta\vec{B}/4\pi n_i m_i$ inside SBs, i.e. $\alpha=V_{||}/|\Delta\vec{V}_A|$ ( $\alpha=\Delta\vec{V}/|\Delta\vec{V}_A|$ when $\Delta\vec{V}~\Delta\vec{B}$), which quantifies the deviation of the perturbation from an Alfv\'enic one. Based on Parker Solar Probe (PSP) observations, we show that $\alpha$ inside SBs has systematically lower values than it has in the pristine solar wind: $\alpha$ inside SBs observed during PSP Encounter 1 were distributed in a range of 0.2-0.9. The upper limit on $\alpha$ is constrained by the requirement that the jump in velocity across the switchback boundary be less than the local Alfv\'en speed. This prevents the onset of shear flow instabilities. The consequence is that the perturbation of the proton bulk velocity in SBs with deflection greater than 60 degrees cannot reach $\alpha=1$ (the Alfv\'enicity condition) and the highest possible $\alpha$ for a SB with the full reversal of B is 0.5. These results have consequences for the interpretation of switchbacks as large amplitude Alfv\'en waves.

The Tianlai cylinder pathfinder is a radio interferometer array to test 21 cm intensity mapping techniques in the post-reionization era. It works in passive drift scan mode to survey the sky visible in the northern hemisphere. To deal with the large instantaneous field of view and the spherical sky, we decompose the drift scan data into m-modes, which are linearly related to the sky intensity. The sky map is reconstructed by solving the linear interferometer equations. Due to incomplete uv coverage of the interferometer baselines, this inverse problem is usually ill-posed, and regularization method is needed for its solution. In this paper, we use simulation to investigate two frequently used regularization methods, the Truncated Singular Value Decomposition (TSVD), and the Tikhonov regularization techniques. Choosing the regularization parameter is very important for its application. We employ the generalized cross validation (GCV) method and the L-curve method to determine the optimal value. We compare the resulting maps obtained with the different regularization methods, and for the different parameters derived using the different criteria. While both methods can yield good maps for a range of regularization parameters, in the Tikhonov method the suppression of noisy modes are more gradually applied, produce more smooth maps which avoids some visual artefacts in the maps generated with the TSVD method.

GRB 230307A is the second brightest gamma-ray burst (GRB) ever detected over 50 years of observations and has a long duration in the prompt emission. Two galaxies are found to be close to the position of GRB 230307A: 1) a distant ($z \sim 3.87$) star-forming galaxy, located at an offset of $\sim 0.2\operatorname{-}0.3$ arcsec from the GRB position (with a projected distance of $\sim 1\operatorname{-}2 \, \rm kpc$); 2) a nearby ($z= 0.065$) spiral galaxy, located at an offset of 30 arcsec (with a projected distance of $\sim 40 \, \rm kpc$). Though it has been found that the brightest GRBs are readily detected in GeV emission by the Fermi Large Area Telescope (LAT), we find no GeV afterglow emission from GRB 230307A. Combining this with the optical and X-ray afterglow data, we find that a circum-burst density as low as $\sim 10^{-5} \operatorname{-} 10^{-4}~{\rm cm^{-3}}$ is needed to explain the non-detection of GeV emission and the multi-wavelength afterglow data, regardless of the redshift of this GRB. Such a low-density disfavors the association of GRB 230307A with the high-redshift star-forming galaxy, since the proximity of the GRB position to this galaxy would imply a higher-density environment. Instead, the low-density medium is consistent with the circumgalactic medium, which agrees with the large offset between GRB 230307A and the low-redshift galaxy. This points to the compact stellar merger origin for GRB 230307A, consistent with the detection of an associated kilonova.

Recent radio observations with Low-Frequency Array (LOFAR) discovered diffuse emission extending beyond the scale of classical radio halos. The presence of such mega halos indicates that the amplification of the magnetic field and acceleration of relativistic particles are working in the cluster outskirts, presumably due to the combination of shocks and turbulence that dissipate energy in these regions. Cosmological magnetohydrodynamical (MHD) simulations of galaxy clusters suggest that solenoidal turbulence has a significant energy budget in the outskirts of galaxy clusters. In this paper, we explore the possibility that this turbulence contributes to the emission observed in mega halos through second-order Fermi acceleration of relativistic particles and the magnetic field amplification by the dynamo. We focus on the case of Abell 2255 and find that this scenario can explain the basic properties of the diffuse emission component that is observed under assumptions that are used in previous literature. More specifically, we conduct a numerical follow-up, solving the Fokker--Planck equation using a snapshot of a MHD simulation and deducing the synchrotron brightness integrated along the lines of sight. We find that a volume-filling emission, ranging between 30 and almost 100% of the projected area depending on our assumptions on the particle diffusion and transport, can be detected at LOFAR sensitivities. Assuming a magnetic field $B\sim0.2\mu$G, as derived from a dynamo model applied to the emitting region, we find that the observed brightness can be matched when $\sim$1% level of the solenoidal turbulent energy flux is channeled into particle acceleration.

Variability is a prominent observational feature of blazars. The high-energy radiation mechanism of jets has always been important but still unclear. In this work, we performed a detailed analysis using Fermi-LAT data across 15 years and obtained GeV light curve information for 78 TeV blazars detected by Fermi. We provided annual GeV fluxes and corresponding spectral indices for the 78 TeV blazars and thorough monthly GeV fluxes for a subsample of 41 bright blazars. Our results suggest a strong correlation between the ${\gamma}$-ray photon index and $\log L_{\rm \gamma}$ for the flat spectrum radio quasars (FSRQs) and high-energy-peaked BL Lacs (HBLs). 14 sources in our sample show significant GeV outbursts/flares above the relatively stable, low-flux light curve, with 6 of them showing a clear sharp peak profile in their 5-day binned light curves. We quantified the variability utilizing the fractional variability parameter $F_{\mathrm{var}}$, and found that the flux of the FSRQs showed significantly stronger variability than that of the BL Lacs. The 41 bright blazars in this work are best fit by a log-normal flux distribution. We checked the spectral behavior and found 11 out of the 14 sources show a 'bluer-when-brighter (BWB)' trend, suggesting this spectral behavior for these TeV blazars at the GeV band arises from the mechanism that the synchrotron-self Compton (SSC) process dominates the GeV emission. Our research offers a systematic analysis of the GeV variability properties of TeV blazars and serves as a helpful resource for further associated blazar studies.

The rotation periods of Ap stars span more than five orders of magnitude. The physical origin of this differentiation remains poorly understood. The consideration of the most slowly rotating Ap stars represents a promising approach to gain insight into the processes at play. The identification of super-slowly rotating Ap (ssrAp) star candidates (defined as Ap stars that have rotation periods longer than 50d) through systematic exploitation of the available TESS observations of Ap stars is an effective approach to build a sample devoid of magnetic bias. In our previous analyses of TESS Cycle 1 and Cycle 2 data, we interpreted the Ap stars showing no photometric variability over the 27-d duration of a TESS sector as being ssrAp star candidates. Here, we apply the same approach to TESS Cycle 3 and Cycle 4 observations of Ap stars. However, two issues may lead to spurious identification of ssrAp star candidates. (1) A considerable fraction of the Ap stars in the existing lists have erroneous or dubious spectral classifications. (2) The TESS data processing may remove part of the variability signal. After critical evaluation of these effects, we report the identification of 25 new ssrAp star candidates and of 8 stars with moderately long periods. Combining this list with the lists of ssrAp stars from Cycles 1 and 2 and with the list of ssrAp stars that were previously known but whose lack of variability was not detected in our study, we confirmed at a higher significance level the conclusions drawn in our earlier work. These include the lower rate of occurrence of super-slow rotation among weakly magnetic Ap stars than among strongly magnetic ones, the probable existence of a gap between ~2 and ~3kG in the distribution of the magnetic field strengths of the ssrAp stars, and the much higher rate of occurrence of rapid oscillations in ssrAp stars than in the whole population of Ap stars.

The energy spectra of particles produced from dark matter (DM) annihilation or decay are one of the fundamental ingredients to calculate the predicted fluxes of cosmic rays and radiation searched for in indirect DM detection. We revisit the calculation of the source spectra for annihilating and decaying DM using the Vincia shower algorithm in Pythia to include QED and QCD final state radiation and diagrams for the Electroweak (EW) corrections with massive bosons, not present in the default Pythia shower model. We take into account the spin information of the particles during the entire EW shower and the off-shell contributions from massive gauge bosons. Furthermore, we perform a dedicated tuning of the Vincia and Pythia parameters to LEP data on the production of pions, photons, and hyperons at the $Z$ resonance and discuss the underlying uncertainties. To enable the use of our results in DM studies, we provide the tabulated source spectra for the most relevant cosmic messenger particles, namely antiprotons, positrons, $\gamma$ rays and the three neutrino flavors, for all the fermionic and bosonic channels and DM masses between 5 GeV and 100 TeV, on https://github.com/ajueid/CosmiXs.git.

An accurate reconstruction of galaxy cluster masses is key to use this population of objects as a cosmological probe. In this work we present a study on the hydrostatic-to-lensing mass scaling relation for a sample of 53 clusters whose masses were reconstructed homogeneously in a redshift range between $z= 0.05$ and $1.07$. The $M_{500}$ mass for each cluster was indeed inferred from the mass profiles extracted from the X-ray and lensing data, without using a priori observable-mass scaling relations. We assessed the systematic dispersion of the masses estimated with our reference analyses with respect to other published mass estimates. Accounting for this systematic scatter does not change our main results, but enables the propagation of the uncertainties related to the mass reconstruction method or used dataset. Our analysis gives a hydrostatic-to-lensing mass bias of $(1-b) =0.739^{+0.075}_{-0.070}$ and no evidence of evolution with redshift. These results are robust against possible subsample differences.

We develop the recipe to separate the spectral counterparts of the AGN NGC 1275 from the emission of the Perseus cluster surrounding it in the spectra observed by Suzaku/XIS cameras with no usage of the spectral fitting models. The Perseus cluster emission reaches higher energies than is typical for the most AGN-situated dense surroundings (i.e. up to 9-10 keV). That is why the separation between the AGN and cluster spectra is especially important in this case. To avoid the degeneracy due to the huge quantity of the spectral fitting parameters such as abundances of elements the cluster consists of, thermal and Compton emission of the nucleus itself, and the jet SSC/IC emission spectral parameters as well we prefer to avoid the spectral fitting usage to perform this task. Instead, we use the spatial resolution of the components and double background subtracting. For this purpose we choose the following regions to collect all the photons from them: (1) circular or square-shaped region around the source (AGN); (2) ring-shaped (or non-overlapped square) region surrounding the AGN (for cluster); (3) remote empty circular region for the background. Having collected the photons from those regions we subtract the background (i.e. photons from the third region) from the source and cluster spectra. Next, we subtract the re-normalized cluster counts from the AGN spectrum; using the relation between the emission line amplitudes in the AGN and cluster spectra as the renormalization coefficient. We have performed this procedure on the whole set of the Suzaku/XIS observational data for NGC 1275 to obtain the cleaned spectra and light curve of the AGN emission in this system.

We investigate the effects of halo kinematics on the dynamics of stellar discs by simulating the evolution of isolated disc-halo systems from equilibrium initial conditions. Our main results come from four simulations where the initial disc is identical and the halo is either treated as a rigid potential or is live with isotropic orbits or orbits that preferentially rotate with or counter to the disc. We confirm previous results that bar formation is more vigorous in models with a live halo than a rigid one and is further enhanced when halo orbits preferentially rotate with the disc. We discuss two types of buckling events with different symmetries about the mid plane, one that occurs just as the bar is forming and the other well after the bar has been established. We also show that warps are most easily excited and maintained when the halo is counter-rotating with the disc, in agreement with theoretical predictions. Our most novel result is the discovery of a rotating halo instability, which causes the disc and halo cusp to spiral outward from the centre of mass of the system whether the halo rotates with the disc or counter to it and also occurs in a disc bulge halo system that does not form a bar. We provide a heuristic linear model that captures the essential dynamics of the instability.

We present results of the search for hard X-ray/soft $\gamma$-ray emission in coincidence with publicly reported (via Transient Name Server, TNS; this http URL) fast radio bursts (FRBs). The search was carried out using continuous Konus-Wind data with 2.944 s time resolution. We perform a targeted search for each individual burst from 581 FRBs, along with a stacking analysis of the bursts from 8 repeating sources in our sample and a separate stacking analysis of the bursts from the non-repeating FRBs. We find no significant associations in either case. We report upper bounds on the hard X-ray (20 - 1500 keV) flux assuming four spectral models, which generally describe spectra of short and long GRBs, magnetar giant flares, and the short burst, coincident with FRB 200428 from a Galactic magnetar. Depending on the spectral model, our upper bounds are in the range of $(0.1 - 2) \times10^{-6}$ erg cm$^{-2}$. For 18 FRBs with known distances we present upper bounds on the isotropic equivalent energy release and peak luminosity. For the nearest FRB 200120E, we derive the most stringent upper bounds of $E_{\text{iso}}\leq$2.0 $\times 10^{44}$ erg and $L_{\text{iso}}\leq$1.2 $\times 10^{44}$ erg s$^{-1}$. Furthermore, we report lower bounds on radio-to-gamma-ray fluence ratio $E_{\text{radio}}/E_{\text{iso}} \geq 10^{-11}-10^{-9}$ and compare our results with previously reported searches and theoretical predictions for high-energy counterparts to FRBs.

While the GeV $\gamma$-ray emission of starburst galaxies (SBG) is commonly thought to arise from hadronic interactions between accelerated cosmic rays and interstellar gas, the origin of the TeV $\gamma$-ray emission is more uncertain. One possibility is that a population of pulsar wind nebulae (PWNe) in these galaxies could be responsible for the TeV $\gamma$-ray emission. In this work, we first synthesize a PWNe population in the Milky Way, and assessed their contribution to the $\gamma$-ray emission of the Galaxy, using a time-dependent model to calculate the evolution of the PWN population. Such synthetic PWN population can reproduce the flux distribution of identified PWNe in the Milky Way given a distribution of the initial state of the pulsar population. We then apply it to starburst galaxies and quantitatively calculate the spectral energy distribution of all PWNe in the SBG NGC 253 and M82. We propose that TeV $\gamma$-ray emission in starburst galaxies can be dominated by PWNe for a wide range of parameter space. The energetic argument requires that $\eta_e \times v_{\rm SN} > 0.01 {\rm yr}^{-1}$, where $\eta_e$ is the fraction the spin-down energy going to electrons and $v_{\rm SN}$ is the supernova rate. By requiring the synchrotron emission flux of all PWNe in the galaxy not exceeding the hard X-ray measurement of NGC 253, we constrain the initial magnetic field strength of PWNe to be $< 400 \mu$G. Future observations at higher energies with LHAASO or next-generation neutrino observatory IceCube-Gen2 will help us to understand better the origin of the TeV $\gamma$-ray emission in SBGs.

We report on the discovery and analysis of the planetary microlensing event OGLE-2019-BLG-1180 with a planet-to-star mass ratio $q \sim 0.003$. The event OGLE-2019-BLG-1180 has unambiguous cusp-passing and caustic-crossing anomalies, which were caused by a wide planetary caustic with $s \simeq 2$, where $s$ is the star-planet separation in units of the angular Einstein radius $\theta_{E}$. Thanks to well-covered anomalies by the Korea Micorolensing Telescope Network (KMTNet), we measure both the angular Einstein radius and the microlens parallax in spite of a relatively short event timescale of $t_{E} = 28$ days. However, because of a weak constraint on the parallax, we conduct a Bayesian analysis to estimate the physical lens parameters. We find that the lens system is a super-Jupiter-mass planet of $M_{p} = 1.75^{+0.54}_{-0.51} M_{J}$ orbiting a late-type star of $M_{h}=0.55^{+0.27}_{-0.26} M_\odot$ at a distance of $D_{L} = 6.1^{+0.9}_{-1.3}$ kpc. The projected star-planet separation is $a_{\perp} = 5.19^{+0.90}_{-1.23}$ au, which means that the planet orbits at about four times the snow line of the host star. Considering the relative lens-source proper motion of $\mu_{rel} = 6$ mas/yr, the lens will be separated from the source by 60 mas in 2029. At that time one can measure the lens flux from adaptive optics imaging of Kec or a next-generation 30 m class telescope. OGLE-2019-BLG-1180Lb represents a growing population of wide-orbit planets detected by KMTNet, so we also present a general investigation into prospects for further expanding the sample of such planets.

Complex organic molecules (COMs) in protoplanetary disks are key to understanding the origin of volatiles in comets in our solar system, yet the chemistry of COMs in protoplanetary disks remains poorly understood. Here we present Atacama Large Millimeter/submillimeter Array (ALMA) Band 3 observations of the disk around the young outbursting star V883 Ori, where the COMs sublimate from ices and are thus observable thanks to the warm condition of the disk. We have robustly identified ten oxygen-bearing COMs including $^{13}$C-isotopologues in the disk-integrated spectra. The radial distributions of the COM emission, revealed by the detailed analyses of the line profiles, show the inner emission cavity, similar to the previous observations in Band 6 and Band 7. We found that the COMs abundance ratios with respect to methanol are significantly higher than those in the warm protostellar envelopes of IRAS 16293-2422 and similar to the ratios in the solar system comet 67P/Churyumov-Gerasimenko, suggesting the efficient (re-)formation of COMs in protoplanetary disks. We also constrained the $^{12}$C/$^{13}$C and D/H ratios of COMs in protoplanetary disks for the first time. The $^{12}$C/$^{13}$C ratios of acetaldehyde, methyl formate, and dimethyl ether are consistently lower ($\sim$ 20-30) than the canonical ratio in the interstellar medium ($\sim$ 69), indicating the efficient $^{13}$C-fractionation of CO. The D/H ratios of methyl formate are slightly lower than the values in IRAS 16293-2422, possibly pointing to the destruction and reformation of COMs in disks. We also discuss the implications for nitrogen and sulfur chemistry in protoplanetary disks.

Ionization cones and relativistic jets give us one of the most large-scale example of active galactic nuclei (AGN) influence on the surrounding gas environment in galaxies and beyond. The study of ionization cones makes it possible not only to test the predictions of the unified model of galactic activity, but also to probe galaxy gas environment and trace how the luminosity of the nucleus changes over time (a light echo). In the external galactic or even extragalactic gas ionization cones create Extended Emission-Line Regions (EELRs) which can span distances from several to hundreds kpc away a host galaxy. We review the recent results of studying the gas kinematics and its ionization properties in EELRs with a special attention to search of fading AGN radiation on the time scale $\mbox{few}\times(10^4-10^5)$ yr. The role of modern narrow-band and integral-field surveys in these researches is also considered.

Studying a centi-parsec supermassive black hole binary (SMBHB) would allow us to explore a new parameter space in active galactic nuclei, and these objects are also potential sources of gravitational waves. We report evidence that an SMBHB with an orbital period of about 30 yr may be resident in the nearby galactic nucleus M81. This orbital period and the known mass of M81 imply an orbital separation of about 0.02 pc. The jet emanating from the primary black hole showed a short period of jet wobbling at about 16.7 yr, superposing a long-term precession at a timescale of several hundred years. Periodic radio and X-ray outbursts were also found two times per orbital period, which could be explained by a double-peaked mass accretion rate variation per binary orbit. If confirmed, M81 would be one of the closest SMBHB candidates, providing a rare opportunity to study the final parsec problem.

(Abridged) In this paper, we present a project of multi-channel wide-field optical sky monitoring system with high temporal resolution -- Small Aperture Imaging Network Telescope (SAINT) -- mostly built from off-the-shelf components and aimed towards searching and studying optical transient phenomena on the shortest time scales. The instrument consists of 12 channels each containing 30cm (F/1.5) objectives mounted on separate mounts with pointing speeds up to 50deg/s. Each channel is equipped with a 4128x4104 pixel, and a set of photometric $griz$ filters and linear polarizers. At the heart of every channel is a custom built reducer-collimator module allowing rapid switching of an effective focal length of the telescope -- due to it the system is capable to operate in either wide-field survey or narrow-field follow-up modes. In the first case, the field of view of the instrument is 470 square degrees and the detection limits (5$\sigma$ level at 5500$\AA$) are 12.5-21 mag for exposure times of 20 ms - 20 min correspondingly. In the second, follow-up regime, all telescopes are oriented towards the single target, and SAINT becomes an equivalent to a 1m telescope, with the field of view reduced to 11$'$ x 11$'$, and the exposure times decreased down to 0.6 ms. Different channels may then have different filters installed, thus allowing a detailed study -- acquiring both color and polarization information -- of a target object with highest possible temporal resolution. The operation of SAINT will allow acquiring an unprecedented amount of data on various classes of astrophysical phenomena, from near-Earth to extragalactic ones, while its multi-channel design and the use of commercially available components allows easy expansion of its scale, and thus performance and detection capabilities.

We present the discoveries of two giant planets orbiting the red giant branch (RGB) star HD 112570 and the red clump (RC) star HD 154391, based on the radial velocity (RV) measurements from Xinglong station and Okayama Astrophysical Observatory (OAO). Spectroscopic and asteroseismic analyses suggest that HD 112570 has a mass of $1.15\pm0.12\,M_{\odot}$, a radius of $9.85\pm0.23\,R_{\odot}$, a metallicity [Fe/H] of $-0.46\pm0.1$ and a ${\rm log}\,g$ of $2.47\pm0.1$. With the joint analysis of RV and Hipparcos-Gaia astrometry, we obtain a dynamical mass of $M_{\rm p}={3.42}_{-0.84}^{+1.4}\ M_{\rm Jup}$, a period of $P={2615}_{-77}^{+85}$ days and a moderate eccentricity of $e={0.20}_{-0.14}^{+0.16}$ for the Jovian planet HD 112570 b. For HD 154391, it has a mass of $2.07\pm0.03\,M_{\odot}$, a radius of $8.56\pm0.05\,R_{\odot}$, a metallicity [Fe/H] of $0.07\pm0.1$ and a ${\rm log}\,g$ of $2.86\pm0.1$. The super-Jupiter HD 154391 b has a mass of $M_{\rm p}={9.1}_{-1.9}^{+2.8}\ M_{\rm Jup}$, a period of $P={5163}_{-57}^{+60}$ days and an eccentricity of $e={0.20}_{-0.04}^{+0.04}$. We found HD 154391 b has one of the longest orbital period among those ever discovered orbiting evolved stars, which may provide a valuable case in our understanding of planetary formation at wider orbits. Moreover, while a mass gap at $4\,M_{\rm Jup}$ seems to be present in the population of giant stars, there appears to be no significant differences in the distribution of metallicity among giant planets with masses above or below this threshold. Finally, The origin of the abnormal accumulation near 2 au for planets around large evolved stars ($R_{\star}>21\,R_{\odot}$), remains unclear.

This study explores the impact of cosmic curvature on structure formation through general relativistic first-order perturbation theory, focusing on scalar fluctuations and excluding anisotropic stress sources. We analyze continuity and Euler equations, incorporating cosmic curvature into Einstein equations. Emphasizing late-time dynamics, we investigate matter density contrast evolution in the presence of cosmic curvature and dark energy perturbations, with a specific focus on sub-Hubble scales. Solving the evolution equation, we conduct data analysis using cosmic chronometers, baryon acoustic oscillations, type Ia supernova observations, and $f\sigma_8$ data. While constraints on certain parameters remain consistent, excluding cosmic curvature tightens constraints on $\Omega_{\rm m0}$ and $\sigma_{\rm 80}$ in $\Lambda$CDM and wCDM models. Intriguingly, the non-phantom behavior of dark energy proves more favorable in both wCDM and CPL models across diverse data combinations.

In this paper, we investigate the interaction between early dark energy (EDE) and cold dark matter, proposing a Yukawa-coupled dark sector model to mitigate cosmological tensions. We utilize the EDE component in the coupled model to relieve the Hubble tension, while leveraging the interaction between dark matter and dark energy to alleviate the large-scale structure tension. The interaction takes the form of Yukawa coupling, which describes the coupling between scalar field and fermion field. We employed various cosmological datasets, including cosmic microwave background radiation, baryon acoustic oscillations, Type Ia supernovae, the local distance-ladder data (SH0ES), and the Dark Energy Survey Year-3 data, to analyze our novel model. Using the Markov Chain Monte Carlo method, our findings reveal that the constrained value of $H_0$ obtained from our new model at a 68\% confidence level is $72.21^{+0.82}_{-0.69}$ km/s/Mpc, effectively resolving the Hubble tension. Similar to the EDE model, the coupled model yields the $S_8$ value that still surpasses the result of the $\Lambda$CDM model. Nevertheless, the best-fit value of $S_8$ obtained from our new model is 0.817, which is lower than the EDE model's result of 0.8316. Consequently, although our model fails to fully resolve the large-scale structure tension, it mitigates the adverse effect of the original EDE model.

Accurate distances are key to obtaining intrinsic properties of astronomical objects such as luminosity or size. Globular clusters (GCs) follow a well-defined relation between their absolute magnitudes and internal stellar velocity dispersions ($\sigma$), offering an independent way to measure distances to their host galaxies via high-resolution spectroscopy. This is reminiscent of the "Faber-Jackson" for elliptical galaxies. However, unlike galaxies, GCs have a very narrow range of mass-to-light ratios and simple star formation histories. Here we show that the GC $M_V - \text{log}_{10}(\sigma)$ relation is linear, whose slope is identical for the Milky Way and M31 GC systems. Based on this, we use 94 Milky Way GCs which have distances from Gaia parallaxes, or proper-motion dispersion profiles to derive a "GC velocity dispersion" distance (GCVD) to M31, obtaining $(m-M)_0=24.51\pm0.08$ ($d=798\pm28$ kpc), in excellent agreement with independent measurements. Combining data for these two galaxies to create a fiducial relation using 296 GCs with high-quality measurements, we obtain a zeropoint uncertainty ($\pm 0.06$ mag) corresponding to a distance uncertainty of $\sim3\%$. We then use GCVD to obtain a distance to the giant elliptical galaxy NGC\,5128 (Centaurus A), finding $(m-M)_0= 27.95\pm0.09$ ($d=3.89\pm0.16$ Mpc). This is in excellent agreement with, and in some cases more precise than, literature estimates from the tip of the red giant branch or surface brightness fluctuations. We apply GCVD to Local Group galaxies with appropriate data and find good agreement with literature values even in cases with only one GC velocity dispersion measurement.

Inflationary and bouncing scenarios are two frameworks that provide the mechanism to overcome the horizon problem as well as generate the primordial perturbations. In this work, we investigate the conservation of perturbations in single-field models of both inflationary and bouncing scenarios, where the quantity, $z = a \, \rm d \phi/{\rm d}\log a$, with $a$ representing the scale factor and $\phi$ denoting the scalar field, decreases with time. We observe that this behaviour occurs during the ultra-slow-roll phase in the context of inflation and the contracting phase in the context of bounce. We show that the conjugate momentum associated with the comoving curvature perturbation during both the ultra-slow-roll phase and the contracting phase of bouncing scenarios is conserved in the super-Hubble limit. We illustrate that, within the framework of inflation, this conservation of momentum allows for the evolution of perturbations across the ultra-slow-roll phase, enabling the calculation of the power spectrum for modes that exit the Hubble radius before the ultra-slow-roll phase begins. Similarly, in the context of a bounce, we can determine the power spectrum after the bounce using this method. We support our approach with both numerical and analytical arguments.

The TeV observations of GRB~221009A provided us with a unique opportunity to analyze the contemporaneous phase in which both prompt and afterglow emissions are seen simultaneously. To describe this initial phase of Gamma-Ray Burst afterglows, we suggest a model for a blast wave with an intermittent energy supply. We treat the blast wave as a two-element structure. The central engine supplies energy to the inner part (shocked ejecta material) via the reverse shock. As the shocked ejecta material expands, its internal energy is transferred to the shocked external matter. We take into account the inertia of the shocked external material so that the pressure difference across this region determines the derivative of the blast wave's Lorentz factor. Applied to GRB~221009A, the model yields a very good fit to the observations of the entire TeV lightcurve except for three regions where there are excesses in the data with respect to the model. Those are well correlated with the three largest episodes of the prompt activity, and thus, we interpret them as the reverse shock emission. Our best-fit solution for GRB~221009A is an extremely narrow jet with an opening angle theta_j approx 0.07^o (500/\Gamma_0) propagating into a wind-like external medium. This extremely narrow angle is consistent with the huge isotropic equivalent energy of this burst, and its inverse jet break explains the very rapid rise of the afterglow. Interestingly, photon-photon annihilation doesn't play a decisive role in the best-fit model.

With almost 15 years of data taken by the Large Area Telescope (LAT) onboard the Fermi satellite we discovered an extended source of GeV emission in the region of the very-high-energy (TeV) source 1LHAASO J1945+2424. This TeV source is more extended than the LAT source. The spectrum of the GeV emission is hard (with a photon spectral index ~1.5) and connects smoothly with that of the TeV source, indicating a likely common origin. In order to explain the origin of the gamma rays we explore scenarios which are typically used for supernova remnants (SNRs) and pulsar wind nebulae (PWN). For an SNR with a single particle population, a leptonic particle distribution in the form of a broken power-law with a break energy of ~3.7 TeV explains the spectrum well, while in the hadronic scenario a simple power-law with a hard spectral index of ~1.64 is necessary. In the PWN scenario, reasonable parameters are obtained for a source age of 10 kyr and current pulsar spin-down luminosity of 1e34 erg/s.

This study aims to improve the photometric calibration of astronomical photo plates. The Sonneberg Observatory's sky patrol was selected, comprising about 300,000 plates, and the digitization workflow is implemented using PyPlate. The challenge is to remove zero point offsets resulting from differences in color sensitivity in the photo plates' emulsion response. By utilizing the Gaia DR3 dataset and the GaiaXPy tool, we are able to obtain a consistent astrometric and photometric calibration of the Sonneberg plates and those of other archives such as APPLAUSE.

Consistent operation of adaptive optics (AO) systems requires the use of a wavefront sensor (WFS) with high sensitivity and low noise. The nonlinear curvature WFS (nlCWFS) has been shown both in simulations and lab experiments to be more sensitive than the industry-standard Shack-Hartmann WFS (SHWFS), but its noise characteristics have yet to be thoroughly explored. In this paper, we develop a spatial domain wavefront error budget for the nlCWFS that includes common sources of noise that introduce uncertainty into the reconstruction process (photon noise, finite bit depth, read noise, vibrations, non-common-path errors, servo lag, etc.). We find that the nlCWFS can out-perform the SHWFS in a variety of environmental conditions, and that the primary challenge involves overcoming speed limitations related to the wavefront reconstructor. The results of this work may be used to inform the design of nlCWFS systems for a broad range of AO applications.

The epoch of hydrogen reionization is complete by $z=5$, but its progression at higher redshifts is uncertain. Measurements of Ly$\alpha$ forest opacity show large scatter at $z<6$, suggestive of spatial fluctuations in neutral fraction ($x_\mathrm{HI}$), temperature, or ionizing background, either individually or in combination. However, these effects are degenerate, necessitating modeling these physics in tandem in order to properly interpret the observations. We begin this process by developing a framework for modeling the reionization history and associated temperature fluctuations, with the intention of incorporating ionizing background fluctuations at a later time. To do this, we generate several reionization histories using semi-numerical code AMBER, selecting histories with volume-weighted neutral fractions that adhere to the observed CMB optical depth and dark pixel fractions. Implementing these histories in the \texttt{Nyx} cosmological hydrodynamics code, we examine the evolution of gas within the simulation, and the associated metrics of the Ly$\alpha$ forest opacity. We find that the pressure smoothing scale within the IGM is strongly correlated with the adiabatic index of the temperature-density relation. We find that while models with 20,000 K photoheating at reionization are better able to reproduce the shape of the observed $z=5$ 1D flux power spectrum than those with 10,000 K, they fail to match the highest wavenumbers. The simulated autocorrelation function and optical depth distributions are systematically low and narrow, respectively, compared to the observed values, but are in better agreement when the reionization history is longer in duration, more symmetric in its distribution of reionization redshifts, or if there are remaining neutral regions at $z<6$. The systematically low variance likely requires the addition of a fluctuating UVB.

The Wide-field Infrared Survey Explorer (WISE, Wright et al. 2010) and its follow-up Near-Earth Object (NEO) mission (NEOWISE, Mainzer et al. 2011) scan the mid-infrared sky twice a year. The spatial and temporal coverage of the resulting database is of utmost importance for variability studies, in particular of young stellar objects (YSOs) which have red $W1{-}W2$ colors. During such an effort, I noticed subarcsecond position offsets between subsequent visits. The offsets do not appear for targets with small $W1{-}W2$ colors, which points to a chromatic origin in the optics, caused by the spacecraft pointing alternating ``forward'' and ``backward'' from one visit to another. It amounts to 0\farcs1 for targets with $W1{-}W2\approx2$. Consideration of this chromatic offset will improve astrometry. This is of particular importance for NEOs that are generally red.

A total of 64 ATOMS sources at different evolutionary stages were selected to investigate the kinematics and dynamics of gas structures under feedback. We identified dense gas structures based on the integrated intensity map of H$^{13}$CO$^+$ J=1-0 emission, and then extracted the average spectra of all structures to investigate their velocity components and gas kinematics. For the scaling relations between velocity dispersion $\sigma$, effective radius $R$ and column density $N$ of all structures, $\sigma-N*R$ always has a stronger correlation compared to $\sigma-N$ and $\sigma-R$. There are significant correlations between velocity dispersion and column density, which may imply that the velocity dispersion originates from gravitational collapse, also revealed by the velocity gradients. The measured velocity gradients for dense gas structures in early-stage sources and late-stage sources are comparable, indicating gravitational collapse through all evolutionary stages. We quantitatively estimated the velocity dispersion generated by the outflows, inflows, ionized gas pressure and radiation pressure, and found that the ionized gas feedback is stronger than other feedback mechanisms. However, although feedback from HII regions is the strongest, it does not significantly affect the physical properties of the embedded dense gas structures. Combining with the conclusions in Zhou+2023 on cloud-clump scales, we suggest that although feedback from cloud to core scales will break up the original cloud complex, the substructures of the original complex can be reorganized into new gravitationally governed configurations around new gravitational centers. This process is accompanied by structural destruction and generation, and changes in gravitational centers, but gravitational collapse is always ongoing.

The eleven year solar cycle is known to affect the global modes of solar acoustic oscillations. In particular, p mode frequencies increase with solar activity. We propose a new method to detect the solar cycle from the p-mode autocorrelation function, and we validate this method using VIRGO/SPM photometric time series from solar cycles 23 and 24. The p-mode autocorrelation function shows multiple wavepackets separated by time lags of $\sim$123 min. Using a one-parameter fitting method (from local helioseismology), we measure the seismic travel times from each wavepacket up to skip number 40. We find that the travel-time variations due to the solar cycle depend sensitively on the skip number, with the strongest signature in odd skips from 17 to 31. Taking the noise covariance into account, the travel-time perturbations can be averaged over all skip numbers to enhance the signal-to-noise ratio. This method is robust to noise, simpler to implement than peak bagging in the frequency domain, and is promising for asteroseismology. We estimate that the activity cycle of a Sun-like star should be detectable with this new method in Kepler-like observations down to a visual magnitude of $m_K \sim 11$. However, for fainter stars, activity cycles are easier to detect in the photometric variability on rotational timescales.

We present GeMS/GSAOI observations of five fast radio burst (FRB) host galaxies with sub-arcsecond localizations. We examine and quantify their spatial distributions and locations with respect to their host galaxy light distributions, finding a median host-normalized offset of 2.09 r_e and in fainter regions of the host. When combined with the FRB sample from Mannings et al. (2021), we find that FRBs are statistically distinct from Ca-rich transients in terms of light and from SGRBs and LGRBs in terms of host-normalized offset. We further find that most FRBs are in regions of elevated local stellar mass surface densities in comparison to the mean global values of their hosts. This, in combination with the combined FRB sample trace the distribution of stellar mass, points towards a possible similarity of the environments of CC-SNe and FRBs. We also find that 4/5 FRB hosts exhibit distinct spiral arm features, and the bursts originating from such hosts tend to appear on or close to the spiral structure of their hosts, with a median distance of 0.53 kpc. With many well-localized FRB detections looming on the horizon, we will be able to better characterize the properties of FRB environments relative to their host galaxies and other transient classes.

X-ray quasi-periodic eruptions(QPEs) from galactic nucleus have been found in several galaxies. Among them, GSN 069 is the only one with a tidal disruption event(TDE), which was recently found to have brightened again 9 years after the main outburst.However, the origin of this TDE is still unclear. By comparing the fallback time with observation, we found it can not be the disruption of the envelope of a single star in the tidal stripping model. Thus, we suggest that it is a disruption of a common envelope(CE).By calculating the fallback rate of such a model, we reproduce the second peak in the observational TDE. If this model is true, this TDE will be the closest one to a direct observation of CE.

By analyzing the Imaging X-ray Polarimetry Explorer (IXPE) observational data, we report that the significant X-ray polarization variability is detected for 1ES 1959+650 and we also find the highest X-ray polarization so far in PKS 2155-304. The X-ray emission in 2-8 keV band of the high-energy peaked BL Lacertae objects (HBLs) is generally ascribed to the synchrotron radiation of relativistic electrons, and thus HBLs are also the main targets of IXPE to investigate the radiation and acceleration mechanisms of particles. In this paper, we report the first IXPE observations of two HBLs. Two times out of four IXPE observations for 1ES 1959+650 detect the significant polarization in 2-8 keV band, and one more in 2-4 keV band. The detected highest polarization degree is 12.4% with an electric vector polarization angle 19.7 degrees in 2-8 keV band. The X-ray polarization of 1ES 1959+650 exhibits the obvious variability, and is accompanied by the variations of polarization angle, flux, and spectrum. For PKS 2155-304, only one observation was performed by IXPE, at which point the X-ray flux of source is almost the historically low state. Interestingly, the detected highest X-ray polarization among blazars is measured in PKS 2155-304. We also find that the obvious variability along with the spectral variation is presented in the simultaneously monitoring Swift-XRT data of PKS 2155-304. We speculate that the dominant X-ray radiations during different IXPE observations are from separate regions in jets and the dominant acceleration mechanism of particles may be also different.

We present a study of the cool gas ($\approx 10^4$ K) traced by MgII absorptions around groups of galaxies in the MEGAFLOW survey. Using a combination of two algorithms we blindly identify 32 groups of more than 5 galaxies at $0.3 < z < 1.5$ with $10.7 < \log_{10}(M/\rm M_{\odot}) < 13.7$. Among them 26 can be used to study potential counterpart MgII absorptions. We report that 21 out of the total 120 MgII absorption systems present in MEGAFLOW are associated with groups. We observe that the MgII rest-frame equivalent width ($W^{2796}_r$) drops at an impact parameter of $\approx 150$ projected kpc from the closest galaxy and $\approx$ one virial radius from the identified group center indicating that MgII halos scale with the mass of the groups.The impact parameter where the covering fraction exceeds $50\%$ is $\log_{10}(b/\rm kpc) = 2.17 \pm 0.47$ $(2 \sigma)$ and $(b/R_{\rm vir}) = 1.67 \pm 0.98$, which is $\approx 3$ times larger than for field galaxies ($\log_{10}(b/\rm kpc)=1.67\pm0.15$). Finally, we estimate the cool gas column density profile in groups (from the $W^{2796}_r$) and show that its shape follows closely the typical dark matter column density profile for halos at similar redshift and masses.

We present, for the first time, a detailed abundance analysis of the carbon star HE 1104$-$0957 based on high resolution (R${\sim}$ 50\,000) spectra. Our analysis shows that the object is an extremely metal-poor star with [Fe/H] $\sim$ $-$2.96. We find that the object shows enhancement of carbon with [C/Fe] $\sim$ 1.82. However, it does not fall into any of the sub-groups of carbon-enhanced metal-poor (CEMP) stars based on the characteristic elemental abundance ratios used for the classification of various CEMP sub-groups. HE 1104$-$0957 is also found to exhibit an enhancement of oxygen and nitrogen with [O/Fe], and [N/Fe] $\sim$ 1.54, and 2.54 respectively. In HE 1104$-$0957, $\alpha$-elements are found to be slightly enhanced with [$\alpha$/Fe] $\sim$ 0.46. Fe-peak elements are also moderately enhanced in HE 1104$-$0957 with a value 0.63 with respect to Fe. Our analysis shows that HE 1104$-$0957 exhibits enhancement of neutron-capture elements, particularly r-process elements. The low-resolution spectra of this object shows the spectral features characteristics of a typical C-R star. However, We find that the surface chemical compositions of this object is contradictory to that expected for a C-R star. It requires a detailed analysis to better understand the abundance anomalies exhibited by this object.

Magnetic fields of molecular clouds in the Central Molecular Zone (CMZ) have been relatively underobserved at sub-parsec resolution. Here we report JCMT/POL2 observations of polarized dust emission in the CMZ, which reveal magnetic field structures in dense gas at ~0.5 pc resolution. The eleven molecular clouds in our sample including two in the western part of the CMZ (Sgr C and a far-side cloud candidate), four around the Galactic longitude 0 (the 50 km s-1 cloud, CO0.02-0.02, the `Stone' and the `Sticks & Straw' among the Three Little Pigs), and five along the Dust Ridge (G0.253+0.016, clouds b, c, d, and e/f), for each of which we estimate the magnetic field strength using the angular dispersion function method. The morphologies of magnetic fields in the clouds suggest potential imprints of feedback from expanding H II regions and young massive star clusters. A moderate correlation between the total viral parameter versus the star formation rate and the dense gas fraction of the clouds is found. A weak correlation between the mass-to-flux ratio and the star formation rate, and a weak anti-correlation between the magnetic field and the dense gas fraction are also found. Comparisons between magnetic fields and other dynamic components in clouds suggest a more dominant role of self-gravity and turbulence in determining the dynamical states of the clouds and affecting star formation at the studied scales.

Many studies have recently documented the orbital response of eccentric binaries accreting from thin circumbinary disks, characterizing the change in binary semi-major axis and eccentricity. We extend these calculations to include the precession of the binary's longitude of periapse induced by the circumbinary disk, and we characterize this precession continuously with binary eccentricity $e_b$ for equal mass components. This disk-induced apsidal precession is prograde with a weak dependence on binary eccentricity when $e_b \lesssim 0.4$ and decreases approximately linearly for $e_b \gtrsim 0.4$; yet at all $e_b$ binary precession is faster than the rates of change to the semi-major axis and eccentricity by an order of magnitude. We estimate that such precession effects are likely most important for sub-parsec separated binaries with masses $\lesssim 10^7 M_\odot$, like LISA precursors. We find that accreting, equal-mass LISA binaries with $M < 10^6 M_\odot$ (and the most massive $M \sim 10^7 M_\odot$ binaries out to $z \sim 3$) may acquire a detectable phase offset due to the disk-induced precession. Moreover, disk-induced precession can compete with General Relativistic precession in vacuum, making it important for observer-dependent electromagnetic searches for accreting massive binaries -- like Doppler boost and binary self-lensing models -- after potentially only a few orbital periods.

Recent observations from several pulsar timing array (PTA) collaborations have unveiled compelling evidence for a stochastic signal in the nanohertz band. This signal aligns remarkably with a gravitational wave (GW) background, potentially originating from the first-order color charge confinement phase transition. Distinct quantum chromodynamics (QCD) matters, such as quarks or gluons, and diverse phase transition processes thereof can yield disparate GW energy density spectra. In this letter, employing the Bayesian analysis on the NANOGrav 15-year data set, we explore the compatibility with the observed PTA signal of the GW from phase transitions of various QCD matter scenarios in the framework of the holographic QCD. We find that the PTA signal can be effectively explained by the GW from the confinement-deconfinement phase transition of pure quark systems in a hard wall model of the holographic QCD where the bubble dynamics, one important source of the GWs, is of the Jouguet detonations. Notably, our analysis decisively rules out the plausibility of the pure gluon QCD-matter scenario and the non-runaway bubble dynamics model for the phase transition in explaining the observed PTA signal.

I briefly discuss the current state of the Planes of Satellite Galaxies Problem in light of some new observational data for satellite galaxies of the Milky Way, Andromeda, Centaurus A, and other systems beyond the Local Group. In particular, I present how a new proper motion measurment for Leo I enhances the overall orbital coherence among the MW's classical satellites and thus its tension with cosmological expectations.

R Coronae Borealis stars (RCBs) are cool supergiants that display non-periodic deep dips in brightness. Recently, a group of `Hot RCB stars` has been discovered to be fast evolving across the HR diagram, as these stars leave the RCB region, with brightness changes at the rate of $\sim$1 mag/century. Perhaps cool RCB stars can also be seen evolving, either increasing in temperature as they evolve to become Hot RCB stars, or perhaps increasing in luminosity as the stars arrive at the RCB region. To seek these changes, the only possible method is to extract archival data going back more than a century, looking for the brightness changes associated with the evolution. I have measured and extracted 323,464 magnitudes (mostly from the Harvard plates and from the AAVSO) for ten cool RCB stars, all with over a century for the light curves, all consistently calibrated to a modern magnitude system. For times away from any dips, these light curves are flat to within the typical uncertainty of $\pm$0.10 mag/century. That is, I see no significant evolution. I also have collected a large database of light curve dips and their properties. From this, the light curves for all the well-observed isolated dips have the same shape, featuring a flat slope for the few days immediately after the minima. Further, I derive a general model for the shape of the light curve for all isolated RCB dips, with a simple equation accurately describing the observed recovery to maximum light.

Acetic acid (CH3COOH) was detected in the gas toward interstellar clouds, hot cores, protostars and comets. Its formation in ice mantles was proposed and acetic acid awaits detection in the infrared spectra of the ice as most other COMs except methanol. The thermal annealing and UV-irradiation of acetic acid in the ice was simulated experimentally in this work under astrophysically relevant conditions. The experiments were performed under ultra-high vacuum conditions. An ice layer was formed by vapor deposition onto a cold substrate, and was warmed up or exposed to UV photons. The ice was monitored by infrared spectroscopy while the molecules desorbing to the gas phase were measured using a quadrupole mass spectrometer. The transformation of the CH3COOH monomers to cyclic dimers occurs at 120 K and the crystal form composed of chain polymers was observed above 160 K during warm-up of the ice. Ice sublimation proceeds at 189 K in our experiments. Upon UV-irradiation simpler species and radicals are formed, which lead to a residue made of complex molecules after warm-up to room temperature. The possible formation of oxalic acid needs to be confirmed. The photodestruction of acetic acid molecules is reduced when mixed with water in the ice. This work may serve to search for the acetic acid photoproducts in lines of sight where this species is detected. A comparison of the reported laboratory infrared spectra with current JWST observations allows to detect or set upper imits on the CH3COOH abundances in interstellar and circumstellar ice mantles.

Complementary metal-oxide-semiconductor (CMOS) sensors are a competitive choice for future X-ray astronomy missions. Typically, CMOS sensors on space astronomical telescopes are exposed to a high dose of irradiation. We investigate the impact of irradiation on the performance of two scientific CMOS (sCMOS) sensors between -30 to 20 degree at high gain mode (7.5 times), including the bias map, readout noise, dark current, conversion gain, and energy resolution. The two sensors are irradiated with 50 MeV protons with a total dose of 5.3*10^10 p/cm^2. After the exposure, the bias map, readout noise and conversion gain at various temperatures are not significantly degraded, nor is the energy resolution at -30 degree. However, after the exposure the dark current has increased by hundreds of times, and for every 20 degree increase in temperature, the dark current also increases by an order of magnitude. Therefore, at room temperature, the fluctuations of the dark currents dominate the noise and lead to a serious degradation of the energy resolution. Moreover, among the 4k * 4k pixels, there are about 100 pixels whose bias at 50 ms has changed by more than 10 DN (~18 e-), and about 10 pixels whose readout noise has increased by over 15 e- at -30 degree. Fortunately, the influence of the dark current can be reduced by decreasing the integration time, and the degraded pixels can be masked by regular analysis of the dark images. Some future X-ray missions will likely operate at -30 degree, under which the dark current is too small to significantly affect the X-ray performance. Our investigations show the high tolerance of the sCMOS sensors for proton radiation and prove their suitability for X-ray astronomy applications.

Simulations from the scales of isolated galaxies to clouds have been instrumental in informing us about molecular cloud formation and evolution. Simulations are able to investigate the roles of gravity, feedback, turbulence, heating and cooling, and magnetic fields on the physics of the interstellar medium, and star formation. Compared to simulations of individual clouds, galactic and sub-galactic scale simulations can include larger galactic scale processes such as spiral arms, bars, and larger supernovae bubbles, which may influence star formation. Simulations show cloud properties and lifetimes in broad agreement with observations. Gravity and spiral arms are required to produce more massive GMCs, whilst stellar feedback, likely photoionisation, leads to relatively short cloud lifetimes. On larger scales, supernovae may be more dominant in driving the structure and dynamics, but photoionisation may still have a role. In terms of the dynamics, feedback is probably the main driver of velocity dispersions, but large scale processes such as gravity and spiral arms may also be significant. Magnetic fields are generally found to decrease star formation on galaxy or cloud scales, and simulations are ongoing to study whether clouds are sub or supercritical on different scales in galaxy scale simulations. Simulations on subgalactic scales, or zoom in simulations, allow better resolution of feedback processes, filamentary structure within clouds, and the study of stellar clusters.

Investigating the response of icy dust aggregates to water ice sublimation is essential for understanding the formation and properties of planetesimals in protoplanetary discs. However, their fate remains unclear, as previous studies suggest aggregates could either survive or completely fall apart to (sub){\mu}m-sized grains. Protoplanetary discs around stars undergoing accretion outbursts represent a unique laboratory to study the ice sublimation process, as the water snowline is pushed outward to regions accessible to current observatories. In this work, we aim to understand the aggregates' response to ice sublimation by focusing on V883 Ori, a system currently undergoing a powerful accretion outburst. We present new analysis of archival high resolution ALMA observations of the protoplanetary disc of V883 Ori at 0.88, 1.3, 2.0, and 3.1 mm, and derive new radial spectral index profiles, which we compare with predictions from one-dimensional dust evolution simulations. In the region of V883 Ori where water ice has sublimated, we find lower spectral indices than previously obtained, indicating the presence of cm-sized particles. Coupled with our dust evolution models, we find that the only way to explain their presence is to assume they formed before the outburst, and survived the sublimation process. The resilience of dust aggregates to such intense events leads us to speculate that it may extend to other environments with more gentle heating, such as pebbles drifting through the water snowline in quiescent protoplanetary discs. In that case, it may alter the formation pathway of dry planetesimals interior to the snowline.

The sky-averaged cosmological 21 cm signal can improve our understanding of the evolution of the early Universe from the Dark Age to the end of the Epoch of Reionization. Although the EDGES experiment reported an absorption profile of this signal, there have been concerns about the plausibility of these results, motivating independent validation experiments. One of these initiatives is the Mapper of the IGM Spin Temperature (MIST), which is planned to be deployed at different remote locations around the world. One of its key features is that it seeks to comprehensively compensate for systematic uncertainties through detailed modeling and characterization of its different instrumental subsystems, particularly its antenna. Here we propose a novel optimizing scheme which can be used to design an antenna applied to MIST, improving bandwidth, return loss, and beam chromaticity. This new procedure combines the Particle Swarm Optimization (PSO) algorithm with a commercial electromagnetic simulation software (HFSS). We improved the performance of two antenna models: a rectangular blade antenna, similar to the one used in the EDGES experiment, and a trapezoidal bow-tie antenna. Although the performance of both antennas improved after applying our optimization method, we found that our bow-tie model outperforms the blade antenna by achieving lower reflection losses and beam chromaticity in the entire band of interest. To further validate the optimization process, we also built and characterized 1:20 scale models of both antenna types showing an excellent agreement with our simulations.

We present literature on abundance determinations in planetary nebulae (PN) as well as public tools that can be used to derive them. Concerning direct methods to derive abundances we discuss in some depth such issues as reddening correction, use of proper densities and temperatures to compute the abundances, correction for unseen ionic stages, effect of stellar absorption on nebular spectra, and error analysis. Concerning photoionization model-fitting, we discuss the necessary ingredients of model stellar atmospheres, the problem of incomplete slit covering and the determination of the goodness of fit. A note on the use of IFU observations is given. The still unsolved problem of temperature fluctuations is briefly presented, with references to more detailed papers. The problem of abundance discrepancies is touched upon with reference to more extensive discussions in the present volume. Finally carbon footprint issues are mentioned in the context of extensive PN modeling and large databases.

High-precision pulsar timing observations are limited in their accuracy by the jitter noise that appears in the arrival time of pulses. Therefore, it is important to systematically characterise the amplitude of the jitter noise and its variation with frequency. In this paper, we provide jitter measurements from low-frequency wideband observations of PSR J0437$-$4715 using data obtained as part of the Indian Pulsar Timing Array experiment. We were able to detect jitter in both the 300 - 500 MHz and 1260 - 1460 MHz observations of the upgraded Giant Metrewave Radio Telescope (uGMRT). The former is the first jitter measurement for this pulsar below 700 MHz, and the latter is in good agreement with results from previous studies. In addition, at 300 - 500 MHz, we investigated the frequency dependence of the jitter by calculating the jitter for each sub-banded arrival time of pulses. We found that the jitter amplitude increases with frequency. This trend is opposite as compared to previous studies, indicating that there is a turnover at intermediate frequencies. It will be possible to investigate this in more detail with uGMRT observations at 550 - 750 MHz and future high sensitive wideband observations from next generation telescopes, such as the Square Kilometre Array. We also explored the effect of jitter on the high precision dispersion measure (DM) measurements derived from short duration observations. We find that even though the DM precision will be better at lower frequencies due to the smaller amplitude of jitter noise, it will limit the DM precision for high signal-to-noise observations, which are of short durations. This limitation can be overcome by integrating for a long enough duration optimised for a given pulsar.

Future observations with next-generation large-area radio telescopes are expected to discover radio pulsars (PSRs) closely orbiting around Sagittarius~A* (Sgr~A*), the supermassive black hole (SMBH) dwelling at our Galactic Center (GC). Such a system can provide a unique laboratory for testing General Relativity (GR), as well as the astrophysics around the GC. In this paper, we provide a numerical timing model for PSR-SMBH systems based on the post-Newtonian (PN) equation of motion, and use it to explore the prospects of measuring the black hole (BH) properties with pulsar timing. We further consider the perturbation caused by the dark matter (DM) distribution around Sgr~A*, and the possibility of constraining DM models with PSR-SMBH systems. Assuming a 5-year observation of a normal pulsar in an eccentric ($e=0.8$) orbit with an orbital period $P_b = 0.5\,$yr, we find that -- with weekly recorded times of arrival (TOAs) and a timing precision of 1 ms -- the power-law index of DM density distribution near the GC can be constrained to about 20%. Such a measurement is comparable to those measurements at the Galactic length scale but can reveal small-scale properties of the DM.

We report on radio timing observations of PSR J0210+5845 which reveal large deviations from typical pulsar spin-down behaviour. We interpret these deviations as being due to binary motion around the $V=13.5$ star 2MASS J02105640$+$5845176, which is coincident in celestial position and distance with the pulsar. Archival observations and new optical spectroscopy identify this star as a B6V star with a temperature of $T_\mathrm{eff}\approx 14\,000$K and a mass of $M_\mathrm{c}= 3.5$ to $3.8$M$_\odot$, making it the lowest mass main-sequence star known orbiting a non-recycled pulsar. We found that the timing observations constrain the binary orbit to be wide and moderately eccentric, with an orbital period of $P_\mathrm{b}=47^{+40}_{-14}$yr and eccentricity $e=0.46^{+0.10}_{-0.07}$. We predict that the next periastron passage will occur between 2030 and 2034. Due to the low companion mass, we find that the probability for a system with the properties of PSR J0210+5845 and its binary companion to survive the supernova is low. We show that a low velocity and fortuitously directed natal kick is required for the binary to remain bound during the supernova explosion, and argue that an electron-capture supernova is a plausible formation scenario for the pulsar.

In this study we investigated the interiors of rocky exoplanets in order to identify those that may have large quantities of water. We modelled the interiors of 28 rocky exoplanets, assuming four different layers - an iron core, a rock mantle, a high-pressure ice layer, and a surface ice/water layer. Due to observational bias, our study is limited to habitable zone exoplanets. We determined a range of possible water mass fractions for each planet consistent with the modelled planetary structures. We calculated the tidal heating experienced by these exoplanets through gravitational interactions with their host stars, assuming a temperature- and composition dependent Maxwell viscoelastic rheology. Assuming radioactive elemental abundances observed in Solar System meteorites, we also calculated the radiogenic heat flux inside the planets. We estimated the probability of the presence of a thick ocean layer in these planets, taking into account the effect of both tidal and radiogenic heating. Our results showed that Proxima Centauri b, Ross 128 b, Teegarden's b and c, GJ 1061 c and d, and TRAPPIST-1 e may have an extended liquid water reservoir. Furthermore, extremely high H2O-content of the exoplanets Kepler-62 f, Kepler-1652 b, Kepler-452 b, and Kepler-442 b suggests that these planets may maintain a water vapour atmosphere and may in fact be examples of larger ocean worlds. Upon the discovery of new rocky exoplanets beyond the habitable zone, our study can be extended to icy worlds.

Metis, the coronagraph on board Solar Orbiter, provides for the first time coronagraphic imaging in the ultraviolet HI Ly-alpha line and, simultaneously, in polarized visible light, thus providing a host of information on the properties of CMEs and solar eruptions like their overall dynamics, time evolution, mass content, and outflow propagation velocity in the expanding corona. We analyzed in this work six CMEs observed by Metis between April and October 2021, which are characterized by a very strong HI Ly-alpha emission. We studied in particular the morphology, kinematics, and the temporal and radial evolution of the emission of such events, focusing on the brightest UV features. The kinematics of the eruptive events under consideration were studied by determining the height-time profiles of the brightest parts on the Metis plane of the sky. Furthermore, the 3D position in the heliosphere of the CMEs were determined by employing co-temporal images from two other coronagraphs: LASCO/C2 onboard SOHO, and COR2 onboard STEREO-A. Finally, the radiometrically calibrated Metis images of the bright UV features were analyzed to provide estimates of their volume and density. From the kinematics and radiometric analyses, we obtained indications of the temperatures of the bright UV cores of these events. The analysis of these strong UV-emitting features associated with coronal mass ejections demonstrates the capabilities of the current constellation of space coronagraphs, Metis, LASCO/C2, and COR2, in providing a complete characterization of the structure and dynamics of eruptive events in their propagation phase from their inception up to several solar radii. Furthermore, we show how the unique capabilities of the Metis instrument to observe these events in both HI Ly-alpha line and polarized VL radiation allow plasma diagnostics on the thermal state of these events.

The ESA space mission Euclid was launched on July 1st, 2023 and is undergoing its science verification phase. In this invited review we show that Euclid means a before and an after for our understanding of ultra-cool dwarfs and substellar-mass objects and their connections with stars, exoplanets and the Milky Way. Euclid enables the study with unprecedented statistical significance a very large ensemble of ultracool dwarfs, the identification of new types of substellar objects, and the determination of the substellar binary fraction and the Initial Mass Function (IMF) in diverse galactic environments from the nearest stellar nurseries to the ancient relics of Galactic formation.

High-resolution cross-correlation methods are widely used to discover and to characterise atomic and molecular species in exoplanet atmospheres. The characteristic cross-correlation signal is typically represented as a function of the velocity of the system, and the semi-amplitude of the planet's orbit. We present Saltire, a fast and simple model that accurately reproduces the shape of such cross-correlation signals, allowing a direct fit to the data by using a minimum set of parameters. We show how to use this model on the detection of atmospheric CO in archival data of the hot Jupiter tau Bootis b, and how Saltire can be used to estimate the semi-amplitude and rest velocity of high brightness-ratio binaries. By including the shape of the signal, we demonstrate that our model allows to robustly derive the signal position up to 10 times more accurate, compared to conventional methods. Furthermore, we discuss the impact of correlated noise and demonstrate that Saltire is a robust tool for estimating systematic uncertainties on the signal position. Saltire opens a new door to analyse high signal-to-noise data to accurately study atmospheric dynamics and to measure precise dynamical masses for exoplanets and faint stellar companions. We show, that the phase-resolved shape of the atmospheric CCF signal can accurately be reproduced, allowing studies of phase-dependent signal changes and to disentangle them from noise and data aliases.

We present a measurement of the mass-metallicity relation (MZR) at cosmic noon, using the JWST near-infrared wide-field slitless spectroscopy obtained by the GLASS-JWST Early Release Science program. By combining the power of JWST and the lensing magnification by the foreground cluster A2744, we extend the measurements of the MZR to the dwarf mass regime at high redshifts. A sample of 50 galaxies with several emission lines is identified across two wide redshift ranges of $z=1.8-2.3$ and $2.6-3.4$ in the stellar mass range of $\log{(M_*/M_\odot)}\in [6.9, 10.0]$. The observed slope of MZR is $0.223 \pm 0.017$ and $0.294 \pm 0.010$ at these two redshift ranges, respectively, consistent with the slopes measured in field galaxies with higher masses. In addition, we assess the impact of the morphological broadening on emission line measurement by comparing two methods of using 2D forward modeling and line profile fitting to 1D extracted spectra. We show that ignoring the morphological broadening effect when deriving line fluxes from grism spectra results in a systematic reduction of flux by $\sim30\%$ on average. This discrepancy appears to affect all the lines and thus does not lead to significant changes in flux ratio and metallicity measurements. This assessment of the morphological broadening effect using JWST data presents, for the first time, an important guideline for future work deriving galaxy line fluxes from wide-field slitless spectroscopy, such as Euclid, Roman, and the Chinese Space Station Telescope.

Spitzer spectral maps reveal a disk of highly luminous, warm (>150 K) H2 in the center of the massive spiral galaxy Messier 58, which hosts a radio-loud AGN. The inner 2.6 kpc of the galaxy appears to be overrun by shocks from the radio jet cocoon. Gemini NIRI imaging of the H2 1-0 S(1) emission line, ALMA CO 2-1, and HST multiband imagery indicate that much of the molecular gas is shocked in-situ, corresponding to lanes of dusty molecular gas that spiral towards the galaxy nucleus. The CO 2-1 and ionized gas kinematics are highly disturbed, with velocity dispersion up to 300 km/s. Dissipation of the associated kinetic energy and turbulence, likely injected into the ISM by radio-jet driven outflows, may power the observed molecular and ionized gas emission from the inner disk. The PAH fraction and composition in the inner disk appear to be normal, in spite of the jet and AGN activity. The PAH ratios are consistent with excitation by the interstellar radiation field from old stars in the bulge, with no contribution from star formation. The phenomenon of jet-shocked H2 may substantially reduce star formation and help to regulate the stellar mass of the inner disk and supermassive black hole in this otherwise normal spiral galaxy. Similarly strong H2 emission is found at the centers of several nearby spiral and lenticular galaxies with massive bulges and radio-loud AGN.

The enormous increase in mid-IR sensitivity and spatial and spectral resolution provided by the JWST spectrographs enables, for the first time, detailed extragalactic studies of molecular vibrational bands. This opens an entirely new window for the study of the molecular interstellar medium in luminous infrared galaxies (LIRGs). We present a detailed analysis of rovibrational bands of gas-phase CO, H$_2$O, C$_2$H$_2$ and HCN towards the heavily-obscured eastern nucleus of the LIRG VV 114, as observed by NIRSpec and MIRI MRS. Spectra extracted from apertures of 130 pc in radius show a clear dichotomy between the obscured AGN and two intense starburst regions. We detect the 2.3 $\mu$m CO bandheads, characteristic of cool stellar atmospheres, in the star-forming regions, but not towards the AGN. Surprisingly, at 4.7 $\mathrm{\mu}$m we find highly-excited CO ($T_\mathrm{ex} \approx 700$ K; 1000 K out to at least rotational level $J = 27$) towards the star-forming regions, but only cooler gas ($T_\mathrm{ex} \approx 170$ K) towards the AGN. We conclude that only mid-infrared pumping through the rovibrational lines can account for the equilibrium conditions found for CO and H$_2$O in the deeply-embedded starbursts. Here the CO bands probe regions with an intense local radiation field inside dusty young massive star clusters or near the most massive young stars. The lack of high-excitation molecular gas towards the AGN is attributed to geometric dilution of the intense radiation from the bright point source. An overview of the relevant excitation and radiative transfer physics is provided in an appendix.

The early solar system contained short-lived radionuclides such as $^{26}$Al (its half-life time $t_{1/2} = 0.7$ Myr), and many hypotheses have been proposed for their origin. One of the possible hypotheses is that when the protoplanetary disk of the solar system had already formed, a very close $(<1\,\mathrm{pc})$ supernova (SN) injected radioactive material directly into the disk. Such a $^{26}$Al injection hypothesis has been tested so far with very limited setups for disk structure and supernova distance, and then by comparing disruption and injection conditions separately. We extend this problem to analytically investigate whether there are conditions under which the surviving disk radius can confine enough $^{26}$Al for planet formation while allowing some disk disruption. We also consider a variety of i) disk mass and structure, ii) $^{26}$Al yields from SNs, and iii) large dust mass fraction $\eta_\mathrm{d}$. We find that $^{26}$Al yields of SN are required as $\gtrsim 2.1\times10^{-3}M_\odot(\eta_\mathrm{d}/0.2)^{-1}$, which is difficult to reproduce given the diversity of ejected $^{26}$Al mass and large dust mass fractions from the supernovae. Furthermore, we find that even if the above conditions are met, the SN shock changes the disk temperature. Our results place a strong constraint on the 'disk injection scenario'; a scenario in which fresh $^{26}$Al of the early Solar System is injected from a supernova into an already formed protosolar nebula is quite challenging. Rather, we suggest that the fresh $^{26}$Al of the early solar system must have been synthesized/injected in other ways.

The study of jet launching in AGN is an important research method to better understand supermassive black holes (SMBHs) and their immediate surroundings. The main theoretical jet launching scenarios invoke either magnetic field lines anchored to the black hole's (BH) accretion disc (Blandford & Payne 1982) or a magnetic field, which is directly connected to its rotating ergosphere (Blandford & Znajek 1977). The nearby and bright radio galaxy 3C84 (NGC1275) is a very suitable target for testing different jet launching mechanisms, as well as for the study of the innermost, sub-parsec scale AGN structure and the jet origin. Very long baseline interferometry (VLBI) - specifically at millimetre wavelengths - offers an unparalleled view into the physical processes in action, in the close vicinity of SMBHs. Utilising such mm-VLBI observations of 3C84, we study the jet kinematics of the VLBI core region of 3C84 by employing all available, high sensitivity 3 mm-VLBI data sets of this source. As part of this analysis we associate the component ejection events with the variability light-curves at different radio frequencies and in the $\gamma$-rays. Furthermore, by cross-correlating these light-curves, we determine their time-lags and draw conclusions regarding the location of the high energy emission close to the jet base.

The variability in the magnetic activity of the Sun is the main source of the observed changes in the plasma and electromagnetic environments within the heliosphere. The primary way in which solar activity affects the Earth's environment is via the solar wind and its transients. However, the relationship between solar activity and solar wind is not the same at the Space Weather and Space Climate time scales. In this work, we investigate this relationship exploiting five solar cycles data of Ca II K index and solar wind parameters, by taking advantage of the Hilbert-Huang Transform, which allows to separate the contribution at the different time scales. By filtering out the high frequency components and looking at decennial time scales, we confirm the presence of a delayed response of solar wind to Ca II K index variations, with a time lag of ~ 3.1-year for the speed and ~ 3.4-year for the dynamic pressure. To assess the results in a stronger framework, we make use of a Transfer Entropy approach to investigate the information flow between the quantities and to test the causality of the relation. The time lag results from the latter are consistent with the cross-correlation ones, pointing out the presence of a statistical significant information flow from Ca II K index to solar wind dynamic pressure that peaks at time lag of 3.6-year. Such a result could be of relevance to build up a predictive model in a Space Climate context.

We evaluate the effectiveness of Early Dark Energy (EDE) in addressing the Hubble tension using data from the completed eBOSS survey, focusing on luminous red galaxies (LRGs), quasars (QSOs), and emission line galaxies (ELGs). We perform cosmological parameter measurements based on full shape analysis of the power spectrum of all three tracers. We conduct this full shape analysis with the effective field theory of large-scale structure (EFTofLSS). EDE is known to strongly suffer from volume projection effects, which makes the interpretation of cosmological constraints challenging. To quantify the volume projection effects within an EDE full shape analysis, we explore the impact of different prior choices on the nuisance parameters of EFTofLSS through an extensive mock study. We compare classical Gaussian priors to the non-informative Jeffreys prior, known to mitigate volume projection effects in $\Lambda$CDM. Our full shape analysis combines eBOSS and BOSS data with Planck, external Baryon Acoustic Oscillation (BAO), PantheonPlus, and SH0ES supernova data. EDE demonstrates to reduce the tension from $5.2\sigma$ to $3\sigma$ compared to $\Lambda$CDM. The derived values at a 68\% credible interval with Gaussian and Jeffreys priors are $H_0=71.73_{-0.86}^{+0.82}$ km/s/Mpc with $f_\mathrm{EDE} = 0.1179_{-0.022}^{+0.025}$ and $H_0=72.03_{-0.87}^{+0.82}$ km/s/Mpc with $f_\mathrm{EDE} = 0.1399_{-0.022}^{+0.023}$, respectively. Although the Hubble tension is mitigated compared to $\Lambda$CDM, the inclusion of eBOSS data amplifies the tension within EDE from $2\sigma$ to $3\sigma$, in contrast to the full shape analysis of BOSS data with Planck, external BAO, PantheonPlus, and SH0ES. This highlights the significance of incorporating additional large-scale structure data in discussions concerning models aiming to resolve the Hubble tension.

Aims: We report the discovery and analysis of a periodic methanol maser in the massive protostar IRAS 20216+4104. Methods: To obtain the light curve, we used the 6.7 GHz methanol maser spectra collected between 2000-2003 and 2009-2023 with the Hartebeesthoek and Torun radio telescopes, as well as spectra from the literature reported prior to 1992. Results: The velocity-integrated flux density shows sinusoidal-like variations with a period of 6.9 +/- 0.03 yr. All but one of the features show periodic changes with a relative amplitude of 2 up to >89. A slightly variable feature displays a moderate anti-correlation between the flux density and the other significantly variable features. The maser emission appears to follow the continuum emission of the red-shifted outflow cavity. A maximum emission of 3.4 and 4.6 mu m precedes the maser peak by 15 % of the period and the (infrared) IR light centroids show time-dependent displacement. The periodic behaviour of the maser and IR emission is likely due to the eclipsing effect from a wobbling inner disk.

Electrons traveling along magnetic field lines from Jupiter to Io, driven by quasi-linear diffusion (QLD), emit synchrotron radiation. By using the small angle approximation, the kinematic equation for the particle distribution gives us the mean pitch angle value. We described how these ultrarelativistic electrons emit radiation in the GHz range when subjected to external forces.

We have targeted the dusty symbiotic mira system HM Sge with four instruments from the IR to the UV. We have used these observations along with archival observations to study how the system has been evolving after its 1975 nova-like outburst. We have detected ro-vibrational water emission in a symbiotic system for the first time using new EXES high spectral resolution infrared spectroscopy. The features, detected in emission, have velocities consistent with the systemic velocity but do not show any clear evidence of high velocity outflows. Mid-infrared photometry and grism spectroscopy show that the oxygen-rich Asymptotic Giant Branch (AGB) dust and dust output has shown little to no change over the past 39 years. In the optical/UV, we detect three main [NII] nebular features that were detected 22 years ago. Two of these features show a small amount of movement corresponding to average outflows speeds of 38 kms and 78 kms since they were previously observed; some previously detected [NII] features are no longer visible. New UV spectroscopy has shown that the nebular environment continues to steadily relax after the system's 1975 outburst. The data suggest however, that the hot component has increased in temperature from 200,000 K in 1989 to now greater than 250,000 K. Our new and archival observations suggest that the evolution of the system after its outburst is swift with little to no major changes after a period of a couple years.

Polarisation is a powerful remote-sensing tool to study the nature of particles scattering the starlight. It is widely used to characterise interplanetary dust particles in the Solar System and increasingly employed to investigate extrasolar dust in debris discs' systems. We aim to measure the scattering properties of the dust from the debris ring around HD 181327 at near-infrared wavelengths. We obtained high-contrast polarimetric images of HD 181327 in the H band with the SPHERE / IRDIS instrument on the Very Large Telescope (ESO). We complemented them with archival data from HST / NICMOS in the F110W filter reprocessed in the context of the Archival Legacy Investigations of Circumstellar Environments (ALICE) project. We developed a combined forward-modelling framework to simultaneously retrieve the scattering phase function in polarisation and intensity. We detected the debris disc around HD 181327 in polarised light and total intensity. We measured the scattering phase function and the degree of linear polarisation of the dust at 1.6 micron in the birth ring. The maximum polarisation is 23.6% +/- 2.6% and occurs between a scattering angle of 70 deg and 82 deg. We show that compact spherical particles made of a highly refractive and relatively absorbing material in a differential power-law size distribution of exponent $-3.5$ can simultaneously reproduce the polarimetric and total intensity scattering properties of the dust. This type of material cannot be obtained with a mixture of silicates, amorphous carbon, water ice, and porosity, and requires a more refracting component such as iron-bearing minerals. We reveal a striking analogy between the near-infrared polarisation of comets and that of HD 181327. The methodology developed here combining VLT/SPHERE and HST/NICMOS may be applicable in the future to combine the polarimetric capabilities of SPHERE with the sensitivity of JWST.

Measurements of the C/O ratio in brown dwarfs are lacking, in part due to past models adopting solar C/O only. We have expanded the ATMO 2020 atmosphere model grid to include non-solar metallicities and C/O ratios in the T dwarf regime. We change the C/O ratio by altering either the carbon or oxygen elemental abundances, and we find that non-solar abundances of these elements can be distinguished based on the shapes of the $H$- and $K$- bands. We compare these new models with medium-resolution ($R\approx1700$), near-infrared ($0.8-2.4\,\mu$m) Gemini/GNIRS spectra of three benchmark late-T dwarfs, GJ 570D, HD 3651B, and Ross 458C. We find solar C/O ratios and best-fitting parameters ($T_\mathrm{eff}$, $\log(g)$, $Z$) broadly consistent with other analyses in the literature based on low-resolution ($R\sim100$) data. The model-data discrepancies in the near-infrared spectra are consistent across all three objects. These discrepancies are alleviated when fitting the Y, J, H and K bands individually, but the resulting best-fit parameters are inconsistent and disagree with the results from the full-spectrum. By examining the model atmosphere properties we find this is due to the interplay of gravity and metallicity on $\mathrm{H_2-H_2}$ collisionally induced absorption. We therefore conclude that there are no significant issues with the molecular opacity tables used in the models at this spectral resolution. Instead, deficiencies are more likely to lie in the model assumptions regarding the thermal structures. Finally, we find a discrepancy between the GNIRS, SpeX, and other near-infrared spectra in the literature of Ross 458C, indicating potential spectroscopic variability.

Superbursts of neutron stars are rare but powerful events explained by the explosive burning of carbon in the deep layers of the outer envelope of the star. In this paper we perform a simulation of superbursts and propose a simple method for describing the neutrino stage of their cooling, as well as a method for describing the evolution of the burst energy on a scale of several months. We note a universal relation for the temperature distribution in the burnt layer at its neutrino cooling stage, as well as the unification of bolometric light curves and neutrino heat loss rates for deep and powerful bursts. We point out the possibility of long-term retention of the burst energy in the star's envelope. The results can be useful for interpretation of superburst observations.

We identify jet-shaped morphology in the core-collapse supernova remnant (SNR) CTB 1 that includes two opposite structural features. We identify these as the imprints of a pair of jets that were among the last jets to explode the massive stellar progenitor of CTB 1. We find the projected angle between the jets' axis and the direction of the pulsar velocity, which is the neutron star natal kick, to be 78 degrees. We tentatively identify possible signatures of a second pair of opposite jets along a different direction. If holds, SNR CTB 1 has a point-symmetric structure. The morphology and large angle of the jets' axis to kick velocity are the expectations of the jittering jets explosion mechanism (JJEM) of core-collapse supernovae.

Extreme adaptive optics instruments have revealed exquisite details on debris discs, allowing to extract the optical properties of the dust particles such as the phase function, the degree of polarisation and the spectral reflectance. These are three powerful diagnostic tools to understand the physical properties of the dust : the size, shape and composition of the dust particles. This can inform us on the population of parent bodies, also called planetesimals, which generate those particles through collisions. It is however very rare to be able to combine all those three observables for the same system, as this requires different high-contrast imaging techniques to suppress the starlight and reveal the faint scattered light emission from the dust. Due to its brightness, the ring detected around the A-type star HR 4796 is a notable exception, with both unpolarised and polarised images covering near-infrared wavelengths. Here, we show how measurements of dust particles in the laboratory can reproduce the observed near-infrared photo-polarimetric properties of the HR 4796 disc. Experimental characterisation of dust allows to bypass the current limitations of dust models to reproduce simultaneously the phase function, the degree of polarisation and the spectral reflectance.

Interpreting the scaling relations followed by galaxies is a fundamental tool for assessing how well we understand galaxy formation and evolution. Several scaling relations involving the galaxy metallicity have been discovered through the years, the foremost of which is the scaling with stellar mass. This so-called mass-metallicity relation is thought to be fundamental and has been subject to many studies in the literature. We study the dependence of the gas-phase metallicity on many different galaxy properties to assess which of them determines the metallicity of a galaxy. We applied a random forest regressor algorithm on a sample of more than 3000 nearby galaxies from the SDSS-IV MaNGA survey. Using this machine-learning technique, we explored the effect of 148 parameters on the global oxygen abundance as an indicator of the gas metallicity. $M_{\rm \star}$/$R_e$, as a proxy for the baryonic gravitational potential of the galaxy, is found to be the primary factor determining the average gas-phase metallicity of the galaxy ($Z_g$). It outweighs stellar mass. A subsequent analysis provides the strongest dependence of $Z_g$ on $M_\star / R_e^{\,0.6}$. We argue that this parameter traces the total gravitational potential, and the exponent $\alpha\simeq 0.6$ accounts for the inclusion of the dark matter component. Our results reveal the importance of the relation between the total gravitational potential of the galaxy and the gas metallicity. This relation is tighter and likely more primordial than the widely known mass-metallicity relation.

Extreme scattering events (ESEs) are observed as dramatic ($>50\%$) drops in flux density that occur over an extended period of weeks to months. Discrete plasma lensing structures are theorized to scatter the radio waves produced by distant sources such as pulsars, causing the signature decrease in flux density and characteristic caustic spikes in ESE light curves. While plasma lens models in the extant literature have reproduced key features of ESE light curves, they have all faced the problem of being highly over-dense and over-pressured relative to the surrounding interstellar medium (ISM) by orders of magnitude. We model ESEs by numerically ray-tracing through analytic, volumetric plasma lens models by solving the eikonal equation. Delaunay triangulation connecting the rays approximates the wavefront, generating a mapping from the observer plane to the source plane to account for multiple-imaging. This eikonal method of ray-tracing is tested against known analytic solutions and is then applied to a three-dimensional Gaussian-distributed electron volume density lens, and a filament model inspired by Grafton et al. (2023). We find convergence of our numerical results with established analytic solutions validating our numerical method, and reproduce ESE-like light curves. Our numerical ray-tracing method lends itself well to exploring the lensing effects of volumetric turbulence as well as sheet-like lenses, which is currently in progress.

We conduct a detailed analysis of quasinormal $f-$mode frequencies in neutron stars (NS), within the linearized General Relativistic formalism. From Bayesian inference, we derived approximately 9000 nuclear Equations of State (EOS) subject to various constraints including nuclear saturation properties, the pure neutron matter EOS constraint obtained within $\chi$EFT, and pQCD at densities relevant to NS cores. The composition and oscillatory dynamics of NS are then investigated using this set. The EOS are transformed into a spectral representation, aiding in the efficient computation of NS properties. The median frequency values of the $f-$mode for NS with masses ranging from 1.4$M_\odot$ to 2.0$M_{\odot}$ lie between 1.80 and 2.20 kHz for our entire EOS set. Our findings do not reveal a strong correlation between $f-$mode frequencies and individual nuclear saturation properties of the EOS. This suggests the need for more complex methods to unravel multiple-parameter relationships. We noticed a strong relationship between the radii and $f-$mode frequencies for different NS masses. Using this correlation along with NICER observations of PSR J0740+6620 and PSR 0030+0451, we obtained constraints that have minimal overlap in the radius domain and differ in the frequency domain from our entire nucleonic EOS set. This indicates that there may be a need to consider additional exotic particles or maybe a deconfined quark phase in the EOS relevant to the NS core. We argue that future observations of the radius or $f-$mode frequency for more than one NS mass, particularly at the extremes, are likely to settle the issue by either ruling out only nucleonic EOS or providing definitive evidence in its favour.

Galactic cosmic rays (CRs) play a crucial role in ionisation, dissociation, and excitation processes within dense cloud regions where UV radiation is absorbed by dust grains and gas species. CRs regulate the abundance of ions and radicals, leading to the formation of more and more complex molecular species, and determine the charge distribution on dust grains. A quantitative analysis of these effects is essential for understanding the dynamical and chemical evolution of star-forming regions. The CR-induced photon flux has a significant impact on the evolution of the dense molecular medium in its gas and dust components. This study is intended to evaluate the flux of UV photons generated by CRs to calculate the photon-induced dissociation and ionisation rates of a vast number of atomic and molecular species, as well as the integrated UV photon flux. Our study takes advantage of recent developments in the determination of the spectra of secondary electrons, in the calculation of state-resolved excitation cross sections of H$_2$ by electron impact, and of photodissociation and photoionisation cross sections. We calculate the H$_2$ level population of each rovibrational level of the $X$, $B$, $C$, $B'$, $D$, $B''$, $D'$ and $a$ states. We then compute the UV photon spectrum of H$_2$ in its line and continuum components between 72 and 700 nm, with unprecedented accuracy as a function of the CR spectrum incident on a molecular cloud, the H$_2$ column density, the isomeric H$_2$ composition, and the dust properties. The resulting photodissociation and photoionisation rates are, on average, smaller than previous determinations by a factor of about 2, with deviations up to a factor of 5. A special focus is given to the photoionisation rates of H$_2$, HF, and H$_2$, as well as to the photodissociation of H$_2$, which we find to be orders of magnitude higher than previous estimates.

This paper presents GPFC, a novel Graphics Processing Unit (GPU) Phase Folding and Convolutional Neural Network (CNN) system to detect exoplanets using the transit method. We devise a fast folding algorithm parallelized on a GPU to amplify low signal-to-noise ratio transit signals, allowing a search at high precision and speed. A CNN trained on two million synthetic light curves reports a score indicating the likelihood of a planetary signal at each period. GPFC improves on speed by three orders of magnitude over the predominant Box-fitting Least Squares (BLS) method. Our simulation results show GPFC achieves 97% training accuracy, higher true positive rate at the same false positive rate of detection, and higher precision at the same recall rate when compared to BLS. GPFC recovers 100% of known ultra-short-period planets in Kepler light curves from a blind search. These results highlight the promise of GPFC as an alternative approach to the traditional BLS algorithm for finding new transiting exoplanets in data taken with Kepler and other space transit missions such as K2, TESS and future PLATO and Earth 2.0.

The latest improvements in the scale and calibration of Type Ia supernovae catalogues allow us to constrain the specific nature and evolution of dark energy through its effect on the expansion history of the universe. We present the results of Bayesian cosmological model comparison on the SNe~Ia catalogue Pantheon+, where Flat $\Lambda$CDM is preferred by the data over all other models and we find moderate evidence ($\Delta \log \mathcal{Z} \sim 2.5$) to reject a number of the alternate dark energy models. The effect of peculiar velocity corrections on model comparison is analysed, where we show that removing the peculiar velocity corrections results in a varying fit on non-$\Lambda$CDM parameters. As well as comparing cosmological models, the Bayesian methodology is extended to comparing the scatter model of the data, testing for non-gaussianity in the Pantheon+ Hubble residuals. We find that adding a scale parameter to the Pantheon+ covariances, or alternately using a multivariate Student's t-distribution fits the data better than the fiducial analysis, producing a cosmology independent evidence increase of $\Delta \log \mathcal{Z} = 2.29 $ and $2.46$ respectively. This improved treatment of the scatter decreases the uncertainty in the constraint on the Hubble constant, finding $H_0 = 73.67 \pm 0.99 $ km s$^{-1}$ Mpc$^{-1}$, in $ 5.7 \sigma$ tension with Planck. We also explore $M_B$ transition models as a potential solution for the Hubble tension, finding no evidence to support these models among the SNe data.

With the advent of the James Webb Space Telescope (JWST), extra-galactic source count studies were conducted down to sub-microJy in the mid-infrared (MIR), which is several tens of times fainter than what the previous-generation infrared (IR) telescopes achieved in the MIR. In this work, we aim to interpret the JWST source counts and constrain cosmic star-formation history (CSFH) and black hole accretion history (BHAH). We employ the backward evolution of local luminosity functions (LLFs) of galaxies to reproduce the observed source counts from sub-microJy to a few tens of mJy in the MIR bands of the JWST. The shapes of the LLFs at the MIR bands are determined using the model templates of the spectral energy distributions (SEDs) for five representative galaxy types (star-forming galaxies, starbursts, composite, AGN type 2 and 1). By simultaneously fitting our model to all the source counts in the six MIR bands, along with the previous results, we determine the best-fit evolutions of MIR LFs for each of the five galaxy types, and subsequently estimate the CSFH and BHAH. Thanks to the JWST, our estimates are based on several tens of times fainter MIR sources, the existence of which was merely an extrapolation in previous studies.

Light curves produced by wide-field exoplanet transit surveys such as CoRoT, Kepler, and TESS are affected by sensor-wide systematic noise which is correlated both spatiotemporally and with other instrumental parameters such as photometric magnitude. Robust and effective systematics mitigation is necessary to achieve the level of photometric accuracy required to detect exoplanet transits and to faithfully recover other forms of intrinsic astrophysical variability. We demonstrate the feasibility of a new exploratory algorithm to remove spatially-correlated systematic noise and detrend light curves obtained from wide-field transit surveys. This spatial systematics algorithm is data-driven and fits a low-rank linear model for the systematics conditioned on a total-variation spatial constraint. The total-variation constraint models spatial systematic structure across the sensor on a foundational level. The fit is performed using gradient descent applied to, a variable reduced least-squares penalty and a modified form of total-variation prior; both the systematics basis vectors and their weighting coefficients are iteratively varied. The algorithm was numerically evaluated against a reference principal component analysis, using both signal injection on a selected Kepler dataset, as well as full simulations within the same Kepler coordinate framework. We find our algorithm to reduce overfitting of astrophysical variability over longer signal timescales (days) while performing comparably relative to the reference method for exoplanet transit timescales. The algorithm performance and application is assessed and future development outlined.

The discovery of the Eye of Horus (EoH), a rare double source-plane lens system ($z_{\rm lens}=$ 0.795; $z_{\rm src}=$ 1.302 and 1.988), has also led to the identification of two high-redshift ($z_{\rm phot}\sim$ 0.8) galaxy clusters in the same field based on the subsequent analysis of the Subaru/Hyper Suprime-Cam (HSC) optical and XMM-Newton X-ray data. The two brightest cluster galaxies (BCGs), one of which is the lensing galaxy of the EoH, are separated by only $\sim$100$"$ ($=$ 0.75 Mpc $<$ $r_{200}$) on the sky, raising the possibility that these two clusters may be physically associated. Here, we present a follow-up optical spectroscopic survey of this EoH field, obtaining 218 secure redshifts using MMT/Binospec. We have confirmed that there indeed exist two massive ($M_{\rm dyn}$ $>$ $10^{14}$ M$_\odot$) clusters of galaxies at $z$ $=$ 0.795 (the main cluster) and at $z=0.769$ (the NE cluster). However, these clusters have a velocity offset of $\sim$4300 km s$^{-1}$, suggesting that this two-cluster system is likely a line-of-sight projection rather than a physically-related association (e.g., a cluster merger). In terms of the properties of cluster-member galaxies, these two $z\sim0.8$ clusters appear well-developed, each harboring an old (age $=$ 3.6-6.0 Gyr) and massive ($M_\mathrm{*}$ $=$ 4.2-9.5 $\times$ $10^{11}$ M$_\odot$) BCG and exhibiting a well-established red sequence (RS). This study underscores the importance of conducting a spectroscopic follow-up for high-redshift cluster candidates because RS-based cluster selections are susceptible to such a projection effect in general.

In this paper, we revisit the infrared (IR) divergences in de Sitter (dS) space using the wavefunction method, and explicitly explore how the resummation of higher-order loops leads to the stochastic formalism. In light of recent developments of the cosmological bootstrap, we track the behaviour of these nontrivial IR effects from perturbation theory to the non-perturbative regime. Specifically, we first examine the perturbative computation of wavefunction coefficients, and show that there is a clear distinction between classical components from tree-level diagrams and quantum ones from loop processes. Cosmological correlators at loop level receive contributions from tree-level wavefunction coefficients, which we dub classical loops. This distinction significantly simplifies the analysis of loop-level IR divergences, as we find the leading contributions always come from these classical loops. Then we compare with correlators from the perturbative stochastic computation, and find the results there are essentially the ones from classical loops, while quantum loops are only present as subleading corrections. This demonstrates that the leading IR effects are contained in the semi-classical wavefunction which is a resummation of all the tree-level diagrams. With this insight, we go beyond perturbation theory and present a new derivation of the stochastic formalism using the saddle-point approximation. We show that the Fokker-Planck equation follows as a consequence of two effects: the drift from the Schr\"odinger equation that describes the bulk time evolution, and the diffusion from the Polchinski's equation which corresponds to the exact renormalization group flow of the coarse-grained theory on the boundary.

After decades of effort in a number of dark matter direct detection experiments, we still do not have any conclusive signal yet. Therefore it is high time we broaden our horizon by building experiments with increased sensitivity for light dark matter, specifically in the sub-MeV mass regime. In this paper, we propose a new detector material, a bilayer stack of graphene for this purpose. Its voltage-tunable low energy sub-eV electronic band gap makes it an excellent choice for the detector material of a light dark matter search experiment. We compute its dielectric function using the random phase approximation and estimate the projected sensitivity for sub-MeV dark matter-electron scattering and sub-eV dark matter absorption. We show that a bilayer graphene dark matter detector can have competitive sensitivity as other candidate target materials, like a superconductor, in this mass regime. The dark matter scattering rate in bilayer graphene is also characterized by a daily modulation from the rotation of the Earth which may help us mitigate the backgrounds in a future experiment.

As experiment charts new territory at the electroweak scale, the enterprise to characterise all possible theories becomes all the more necessary. In the absence of new particles, this ambitious enterprise is attainable and has led to the Higgs Effective Field Theory (HEFT) as the most general characterising framework, containing the Standard Model Effective Field Theory (SMEFT) as a subspace. The characterisation of this theory space led to the dichotomy SMEFT vs. HEFT\SMEFT as the two possible realisations of symmetry breaking. The criterion to distinguish these two possibilities is non-local in field space, and phenomena which explore field space beyond the neighbourhood of the vacuum manifold are in a singular position to tell them apart. Cosmology allows for such phenomena, and this work focuses on HEFT\SMEFT, the less explored of the two options, to find that first order phase transitions with detectable gravitational wave remnants, domain wall formation and vacuum decay in the far, far distant future can take place and single out HEFT\SMEFT. Results in cosmology are put against LHC constraints, and the potential of future ground- and space-based experiments to cover parameter space is discussed.

In the first three observation runs, ground-based gravitational wave (GW) detectors have observed close to 100 compact binary coalescence (CBC) events. The GW detection rates for CBCs are expected to increase with improvements in the sensitivity of the International Gravitational-Wave Observatory Network (IGWN). However, with improved sensitivity, non-Gaussian instrumental transients or ``glitches'' are expected to adversely affect GW searches and characterisation algorithms. The most detrimental effect is due to short-duration glitches, which mimic the morphology of short-duration GW transients, in particular Intermediate-mass black hole (IMBH) binaries. They can be easily misidentified as astrophysical signals by current searches, and if included in astrophysical analyses, glitches mislabelled as IMBH binaries can affect IMBH population studies. In this work, we introduce a new similarity metric that quantifies the consistency of astrophysical parameters across the detector network and helps to distinguish between IMBH binaries and short-duration, loud glitches which mimic such binaries. We develop this method using a simulated set of IMBH binary signals and a collection of noise transients identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors.

In this work, we study the impact of the environment around a black hole in detail. We introduce non-vanishing radial pressure in a manner analogous to compact stars. We examine both isotropic and anisotropic fluid configurations with and without radial pressure respectively. Our focus extends beyond just dark matter density to the vital role of the energy condition and sound speed in the spacetime of a black hole immersed in matter. In cases of anisotropic pressure with vanishing radial pressure, all profiles violate the dominant energy condition near the BH, and the tangential sound speed exceeds light speed for all dark matter profiles. In our second approach, without assuming vanishing radial pressure, we observe similar violations and superluminal sound speeds. To rectify this, we introduce a hard cutoff for the sound speed, ensuring it remains subluminal. As a consequence, the energy condition is also satisfied. However, this results in increased density and pressure near the BH. This raises questions about the sound speed and its impact on the density structure, as well as questions about the validity of the model itself. With the matter distribution, we also compute the metric for different configurations. It reveals sensitivity to the profile structure. The metric components point towards the horizon structure.

The radiation transfer equation is widely used for simulating such as heat transfer in engineering, diffuse optical tomography in healthcare, and radiation hydrodynamics in astrophysics. By combining the lattice Boltzmann method, we propose a quantum algorithm for radiative transfer. This algorithm encompasses all the essential physical processes of radiative transfer: absorption, scattering, and emission. Our quantum algorithm exponentially accelerates radiative transfer calculations compared to classical algorithms. In order to verify the quantum algorithm, we perform quantum circuit simulation using IBM Qiskit Aer and find good agreement between our numerical result and the exact solution. The algorithm opens new application of fault-tolerant quantum computers for plasma engineering, telecommunications, nuclear fusion technology, healthcare and astrophysics.

Type-II seesaw leptogenesis is a model that integrates inflation, baryon number asymmetry, and neutrino mass simultaneously. It employs the Affleck-Dine mechanism to generate lepton asymmetry, with the Higgs bosons serving as the inflaton. Previous studies assumed inflation to occur in a valley of the potential, employing the single-field approximation. In this work, we explore an alternative scenario for the type-II seesaw leptogenesis, where the inflation takes place along a ridge of the potential. Firstly, we conduct a comprehensive numerical calculation in the canonical scenario, where inflation occurs in a valley, confirming the effectiveness of the single-field approximation. Then, we introduce a novel scenario wherein inflation initiates along the potential's ridge and transitions to the valley in the late stages. In this case, the single-field inflation approximation is no longer valid, yet leptogenesis is still successfully achieved. We find that this scenario can generate a significant non-Gaussianity signature, offering testable predictions for future experiments.

We introduce "Class Symbolic Regression" a first framework for automatically finding a single analytical functional form that accurately fits multiple datasets - each governed by its own (possibly) unique set of fitting parameters. This hierarchical framework leverages the common constraint that all the members of a single class of physical phenomena follow a common governing law. Our approach extends the capabilities of our earlier Physical Symbolic Optimization ($\Phi$-SO) framework for Symbolic Regression, which integrates dimensional analysis constraints and deep reinforcement learning for symbolic analytical function discovery from data. We demonstrate the efficacy of this novel approach by applying it to a panel of synthetic toy case datasets and showcase its practical utility for astrophysics by successfully extracting an analytic galaxy potential from a set of simulated orbits approximating stellar streams.

We investigate the extension to finite temperatures and neutrino chemical potentials of a recently developed nonlocal chiral quark model approach to the equation of state of neutron star matter. We consider two light quark flavors and current-current interactions in the scalar-pseudoscalar, vector, and diquark pairing channels, where the nonlocality of the currents is taken into account by a Gaussian form factor that depends on the spatial components of the 4-momentum. Within this framework, we analyze order parameters, critical temperatures, phase diagrams, equation of state, and mass-radius relations for different temperatures and neutrino chemical potentials. For parameters of the model that are constrained by recent multi-messenger observations of neutron stars, we find that the mass-radius diagram for isothermal hybrid star sequences exhibits the thermal twin phenomenon for temperatures above 30 MeV.

Following the first science results of the LUX-ZEPLIN (LZ) experiment, a dual-phase xenon time projection chamber operating from the Sanford Underground Research Facility in Lead, South Dakota, USA, we report the initial limits on a model-independent non-relativistic effective field theory describing the complete set of possible interactions of a weakly interacting massive particle (WIMP) with a nucleon. These results utilize the same 5.5 t fiducial mass and 60 live days of exposure collected for the LZ spin-independent and spin-dependent analyses while extending the upper limit of the energy region of interest by a factor of 7.5 to 270~keV$_\text{nr}$. No significant excess in this high energy region is observed. Using a profile-likelihood ratio analysis, we report 90% confidence level exclusion limits on the coupling of each individual non-relativistic WIMP-nucleon operators for both elastic and inelastic interactions in the isoscalar and isovector bases.

Orbital forcing plays a key role in pacing the glacial-interglacial cycles. However, the mechanistic linkages between the orbital parameters - eccentricity, obliquity, and precession - and global ice volume remain unclear. Here, we investigate the effect of Earth's orbitally governed incoming solar radiation (that is, insolation) on global ice volume over the past 800,000 years. We consider a simple linear model of ice volume that imposes minimal assumptions about its dynamics. We find that this model can adequately reproduce the observed ice volume variations for most of the past 800,000 years, with the notable exception of Marine Isotope Stage 11. This suggests that, aside from a few extrema, the ice volume dynamics primarily result from an approximately linear response to orbital forcing. We substantiate this finding by addressing some of the key criticisms of the orbitally forced hypothesis. In particular, we show that eccentricity can significantly vary the ocean temperature without the need for amplification on Earth. We also present a feasible mechanism to explain the absence of eccentricity's 400,000 year period in the ice volume data. This requires part of the forcing from eccentricity to be lagged via a slow-responding mechanism, resulting in a signal that closer approximates the change in eccentricity. A physical interpretation of our model is proposed, using bulk ocean and surface temperatures as intermediate mechanisms through which the orbital parameters affect ice volume. These show reasonable alignment with their relevant proxy data, though we acknowledge that these variables likely represent a combination of mechanisms.

[Abridged abstract] Large Language Models (LLMs) can solve some undergraduate-level to graduate-level physics textbook problems and are proficient at coding. Combining these two capabilities could one day enable AI systems to simulate and predict the physical world. We present an evaluation of state-of-the-art (SOTA) LLMs on PhD-level to research-level computational physics problems. We condition LLM generation on the use of well-documented and widely-used packages to elicit coding capabilities in the physics and astrophysics domains. We contribute $\sim 50$ original and challenging problems in celestial mechanics (with REBOUND), stellar physics (with MESA), 1D fluid dynamics (with Dedalus) and non-linear dynamics (with SciPy). Since our problems do not admit unique solutions, we evaluate LLM performance on several soft metrics: counts of lines that contain different types of errors (coding, physics, necessity and sufficiency) as well as a more "educational" Pass-Fail metric focused on capturing the salient physical ingredients of the problem at hand. As expected, today's SOTA LLM (GPT4) zero-shot fails most of our problems, although about 40\% of the solutions could plausibly get a passing grade. About $70-90 \%$ of the code lines produced are necessary, sufficient and correct (coding \& physics). Physics and coding errors are the most common, with some unnecessary or insufficient lines. We observe significant variations across problem class and difficulty. We identify several failure modes of GPT4 in the computational physics domain. Our reconnaissance work provides a snapshot of current computational capabilities in classical physics and points to obvious improvement targets if AI systems are ever to reach a basic level of autonomy in physics simulation capabilities.

We examine various exact solutions in "Cotton Gravity" (CG), a new gravity theory that provides an extension of General Relativity (GR) based on the Cotton tensor. Using an alternative formulation of the field equations in terms of a Codazzi tensor, we obtain various non-trivial CG exact solutions that generalize known GR solutions: FLRW cosmologies, Lemaitre-Tolman-Bondi (LTB) and Szekeres dust solutions, as well as static perfect fluid spheres and solutions with a shear-free 4 velocity. We show that CG modifies the spatial curvature of the nonstatic GR solutions. Demanding a well posed initial value formulation keeps the same dynamics of FLRW models of GR, but with the cosmological constant interpreted as constant spatial curvature. In other solutions the modification of spatial curvature allows for self-consistent significant changes in the dynamics, an time and spece dependent evolution from decelerated to accelerated expansion driven by negative spatial curvature and without necessarily assuming a dark energy source or imposing a cosmological constant. The $\Lambda$CDM model naturally emerges as the unique FLRW dust model of CG with constant negative spatial curvature. Static fluid spheres in the weak field regime of CG allow for modeling the flattening of rotation velocities in galactic systems without assuming dark matter. The methods we have presented can be improved to be able to obtain more general solutions that will facilitate the application of CG to current open problems in gravitational systems in general.