Papers for Friday, Oct 06 2023

DRAGONS (Data Reduction for Astronomy from Gemini Observatory North and South) is a platform for the reduction and processing of astronomical data. The Python-based, open-source package includes infrastructure for automation and algorithms for the processing of imaging and spectroscopic data, up to the analysis-ready stage. DRAGONS currently focuses on the reduction of Gemini data, although it allows for support of data from other instruments and telescopes through third-party extensions. Its latest release (v3.1) enables automated reduction of all currently-active Gemini imaging facility instruments, as well as optical longslit spectroscopic data, acquired with GMOS.

The nonlinear curvature wavefront sensor (nlCWFS) offers improved sensitivity for adaptive optics (AO) systems compared to existing wavefront sensors, such as the Shack-Hartmann. The nominal nlCWFS design uses a series of imaging planes offset from the pupil along the optical propagation axis as inputs to a numerically-iterative reconstruction algorithm. Research into the nlCWFS has assumed that the device uses four measurement planes configured symmetrically around the optical system pupil. This assumption is not strictly required. In this paper, we perform the first systematic exploration of the location, number, and spatial sampling of measurement planes for the nlCWFS. Our numerical simulations show that the original, symmetric four-plane configuration produces the most consistently accurate results in the shortest time over a broad range of seeing conditions. We find that the inner measurement planes should be situated past the Talbot distance corresponding to a spatial period of $r_0$. The outer planes should be large enough to fully capture field intensity and be situated beyond a distance corresponding to a Fresnel-number-scaled equivalent of $Z\approx50$ km for a $D=0.5$ m pupil with $\lambda=532$ nm. The minimum spatial sampling required for diffraction-limited performance is 4-5 pixels per $r_0$ as defined in the pupil plane. We find that neither three-plane nor five-plane configurations offer significant improvements compared to the original design. These results can impact future implementations of the nlCWFS by informing sensor design.

Early JWST observations that targeted so-called double-break sources (attributed to Lyman and Balmer breaks at $z>7$), reported a previously unknown population of very massive, evolved high-redshift galaxies. This surprising discovery led to a flurry of attempts to explain these objects' unexpected existence including invoking alternatives to the standard $\Lambda$CDM cosmological paradigm. To test these early results, we adopted the same double-break candidate galaxy selection criteria to search for such objects in the JWST images of the CAnadian NIRISS Unbiased Cluster Survey (CANUCS), and found a sample of 19 sources over five independent CANUCS fields that cover a total effective area of $\sim60\,$arcmin$^2$ at $z\sim8$. However, (1) our SED fits do not yield exceptionally high stellar masses for our candidates, while (2) spectroscopy of five of the candidates shows that while all five are at high redshifts, their red colours are due to high-EW emission lines in star-forming galaxies rather than Balmer breaks in massive, evolved systems. Additionally, (3) field-to-field variance leads to differences of $\sim 1.5$ dex in the maximum stellar masses measured in the different fields, suggesting that the early single-field JWST observations may have suffered from cosmic variance and/or sample bias. Finally, (4) we show that the presence of even a single massive outlier can dominate conclusions from small samples such as those in early JWST observations. In conclusion, we find that the double-break sources in CANUCS are not sufficiently massive or numerous to warrant questioning the standard $\Lambda$CDM paradigm.

JWST is providing the unique opportunity to directly study feedback processes regulating star formation (SF) in early galaxies. The two $z>5$ quiescent systems (JADES-GS-z7-01-QU and MACS0417-z5BBG) detected so far show a recent starburst after which SF is suppressed. To clarify whether such quenching is due to supernova (SN) feedback, we have developed a minimal physical model. We derive a condition on the minimum star formation rate, $\rm SFR_{min}$, lasting for a time interval $\Delta t_{b}$, required to quench SF in a galaxy at redshift $z$, with gas metallicity $Z$, and hosted by a halo of mass $M_h$. We find that lower $(z, Z, M_h)$ systems are more easily quenched. We then apply the condition to JADES-GS-z7-01-QU ($z=7.3$, $M_\star=10^{8.6} M_\odot$) and MACS0417-z5BBG ($z=5.2$, $M_\star=10^{7.6} M_\odot$), and find that SN feedback largely fails to reproduce the observed quenched SF history. Alternatively, we suggest that SF is rapidly suppressed by radiation-driven dusty outflows sustained by the high specific SFR (43 and 25 Gyr$^{-1}$, respectively) of the two galaxies. Our model provides a simple tool to interpret the SF histories of post-starburst galaxies, and unravel quenching mechanisms from incoming JWST data.

We present a tentative constraint on cosmological parameters $\Omega_m$ and $\sigma_8$ from a joint analysis of galaxy clustering and galaxy-galaxy lensing from DESI Legacy Imaging Surveys Data Release 9 (DR9), covering approximately 10000 square degrees and spanning the redshift range of 0.1 to 0.9. To study the dependence of cosmological parameters on lens redshift, we divide lens galaxies into seven approximately volume-limited samples, each with an equal width in photometric redshift. To retrieve the intrinsic projected correlation function $w_{\rm p}(r_{\rm p})$ from the lens samples, we employ a novel method to account for redshift uncertainties. Additionally, we measured the galaxy-galaxy lensing signal $\Delta\Sigma(r_{\rm p})$ for each lens sample, using source galaxies selected from the shear catalog by applying our \texttt{Fourier\_Quad} pipeline to DR9 images. We model these observables within the flat $\Lambda$CDM framework, employing the minimal bias model. To ensure the reliability of the minimal bias model, we apply conservative scale cuts: $r_{\rm p} > 8$ and $12 ~h^{-1}{\rm Mpc}$, for $w_{\rm p}(r_{\rm p})$ and $\Delta\Sigma(r_{\rm p})$, respectively. Our findings suggest a mild tendency that $S_8 \equiv \sigma_8 \sqrt{\Omega_m/0.3} $ increases with lens redshift, although this trend is only marginally significant. When we combine low redshift samples, the value of $S_8$ is determined to be $0.84 \pm 0.02$, consistent with the Planck results but significantly higher than the 3$\times$ 2pt analysis by 2-5$\sigma$. Despite the fact that further refinements in measurements and modeling could improve the accuracy of our results, the consistency with standard values demonstrates the potential of our method for more precise and accurate cosmology in the future.

Merger events can trigger gas accretion onto supermassive black holes (SMBHs) sitting at the centre of galaxies, and form close pairs of active galactic nuclei (AGN). The fraction of AGN in pairs gives key information to constrain the environmental properties and evolution of SMBHs and their host galaxies. However, the identification of dual AGN is difficult, and only very few have been found in the distant Universe so far. We report the serendipitous discovery of a triple AGN and four dual AGN (one considered as a candidate), with projected separations in the range 3-28 kpc. Their AGN classification is mostly based on classical optical emission line flux ratios, as observed with the Near-InfraRed Spectrograph (NIRSpec) on the James Webb Space Telescope (JWST), and is complemented with additional multi-wavelength diagnostics. The identification of these multiple AGN out of the 17 AGN systems in our GA-NIFS survey (i.e. ~ 20-30%), suggests that they might be more common than expected from the most recent cosmological simulations, which predict a fraction of dual AGN at least one order of magnitude smaller. This work highlights the exceptional capabilities of NIRSpec for detecting distant dual AGN, and prompts new investigations to better constrain their fraction across the cosmic time, and to inform upcoming cosmological simulations.

Our concordance cosmological model predicts that galaxy clusters grow at the intersection of filaments structuring the cosmic web stretching tens of Mega parsecs. Although this hypothesis has been supported by the baryonic components, no observational study has detected the dark matter component of the intracluster filaments (ICFs), the terminal segment of the large-scale cosmic filaments at their conjunction with individual clusters. We report weak-lensing detection of ICFs in the Coma cluster field from the ~12 sq. deg Hyper Suprime-Cam imaging data. The detection is based on two methods: matched-filter technique and shear-peak statistic. The matched-filter technique (shear-peak statistic) yields detection significances of 6.6- (3.1) $\sigma$ and 3.6- (2.8) $\sigma$ for the northern and western ICFs at 110$^{\circ}$ and 340$^{\circ}$, respectively. Both ICFs are highly correlated with the overdensities in the WL mass reconstruction and are well-aligned with the known large-scale ($>10$ Mpc) cosmic filaments comprising the Coma supercluster.

We investigate the joint primary mass, mass ratio, and redshift distribution of astrophysical black holes using the gravitational wave events detected by the LIGO-Virgo-KAGRA collaboration and included in the third gravitational wave transient catalogue. We reconstruct this distribution using Bayesian non-parametric methods, which are data-driven models able to infer arbitrary probability densities under minimal mathematical assumptions. We find evidence for the evolution with redshift of both the primary mass and mass ratio distribution: our analysis shows the presence of two distinct sub-populations in the primary mass - redshift plane, with the lighter population, $\lesssim$ 20 $M_\odot$, disappearing at higher redshifts, $z > 0.4$. The mass ratio distribution shows no support for symmetric binaries. The observed population of coalescing binary black holes evolves with look-back time, suggesting a trend in metallicity with redshift and/or the presence of multiple, redshift-dependent formation channels.

Pristine_183.6849+04.8619 (P1836849) is an extremely metal-poor ([Fe/H]$=-3.3\pm0.1$) star on a prograde orbit confined to the Galactic disk. Such stars are rare and may have their origins in protogalactic fragments that formed the early Milky Way, in low mass satellites that were later accreted by the Galaxy, or forming in situ in the Galactic plane. Here we present a chemo-dynamical analysis of the spectral features between $3700-11000$\r{A} from a high-resolution spectrum taken during Science Verification of the new Gemini High-resolution Optical SpecTrograph (GHOST). Spectral features for many chemical elements are analysed (Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Fe, Ni), and valuable upper limits are determined for others (C, Na, Sr, Ba), which are all important tracers of the earliest epochs of star formation in the Galaxy. This main sequence star exhibits several rare chemical signatures, including (i) extremely low metallicity for a star in the Galactic disk, (ii) very low abundances of the light $\alpha$-elements (Na, Mg, Si) compared to metal-poor stars in the Galactic halo or disk, and (iii) unusually large abundances of Cr and Mn, where [Cr, Mn/Fe]$_{\rm NLTE}>+0.5$. A simple comparison to theoretical yields from supernova models suggests that two low mass Population III objects (one 10 M$_\odot$ supernova and one 17 M$_\odot$ hypernova) can reproduce the abundance pattern well (reduced $\chi^2<1$). When this star is compared to two other extremely metal-poor stars with planar orbits, differences in both chemistry and kinematics imply there is little evidence for a common origin. The unique chemistry of P1836849 is discussed in terms of the earliest stages in the formation of the Milky Way.

Galaxy-scale gravitational lenses are often modeled with two-component mass profiles where one component represents the stellar mass and the second is an NFW profile representing the dark matter. Outside of the spherical case, the NFW profile is costly to implement, and so it is approximated via two different methods; ellipticity can be introduced via the lensing potential (NFWp) or via the mass by approximating the NFW profile as a sum of analytical profiles (NFWm). While the NFWp method has been the default for lensing applications, it gives a different prescription of the azimuthal structure, which we show introduces ubiquitous gradients in ellipticity and boxiness in the mass distribution rather than having a constant elliptical shape. Because unmodeled azimuthal structure has been shown to be able to bias lens model results, we explore the degree to which this introduced azimuthal structure can affect the model accuracy. We construct input profiles using composite models using both the NFWp and NFWm methods and fit these mocks with a power-law elliptical mass distribution (PEMD) model with external shear. As a measure of the accuracy of the recovered lensing potential, we calculate the value of the Hubble parameter $H_0$ one would determine from the lensing fit. We find that the fits to the NFWp input return $H_0$ values which are systematically biased by about $3\%$ lower than the NFWm counterparts. We explore whether such an effect is attributable to the mass sheet transformation (MST) by using an MST-independent quantity, $\xi_2$. We show that, as expected, the NFWm mocks are degenerate with PEMD through an MST. For the NFWp, an additional bias is found beyond the MST due to azimuthal structures {\it exterior to the Einstein radius}. We recommend modelers use an NFWm prescription in the future, such that azimuthal structure can be introduced explicitly rather than implicitly.

We consider the effect of including an Active Galactic Nuclei (AGN) component when fitting spectral energy distributions of 109 spectroscopically confirmed $z\approx 3.5-12.5$ galaxies with JWST. Remarkably, we find that the resulting cosmic star formation history is $\approx 0.9$ dex lower at $z\gtrsim 9.5$ when an AGN component is included in the fitting. This alleviates previously reported excess star formation at $z\gtrsim 9.5$ compared to models based on typical baryon conversion efficiencies inside dark matter halos. We find that the individual stellar masses and star formation rates can be as much as $\approx 4$ dex lower when fitting with an AGN component. These results highlight the importance of considering both stellar mass assembly and super massive black hole growth when interpreting the light distributions of among the first galaxies to ever exist.

Using the cosmological simulations IllustrisTNG, we perform a comprehensive analysis of quiescent, massive galaxies at $z \gtrsim 3$. The goal is to understand what suppresses their star formation so early in cosmic time, and how other similar mass galaxies remain highly star-forming. We find that active galactic nuclei (AGN) feedback is the primary cause of halting star formation in early, massive galaxies. Not only do the central supermassive black holes of the quenched galaxies have earlier seed times, but they also grow faster than in star-forming galaxies. As a result, the quenched galaxies are exposed to AGN feedback for longer, and experience the kinetic, jet mode of the AGN feedback earlier than the star-forming galaxies. The release of kinetic energy reduces inflows of gas while likely maintaining outflows, which keeps a low cold gas fraction and decreases the star formation of the galaxies down to a state of quiescence. In addition to AGN feedback, we also investigate the influence of the large-scale environment. While mergers do not play a significant role in the quenching process, the quenched galaxies tend to reside in more massive halos and denser regions during their evolution. As this provides a greater initial amount of infalling gas to the galaxies, the large-scale environment can mildly affect the fate of the central black hole growth and, via AGN feedback, contribute to star-formation quenching.

Many particles are accelerated during solar flares. To understand the acceleration and propagation processes of electrons, we require the pitch-angle distributions of the particles. The pitch angle of accelerated electrons has been estimated from the propagation velocity of a nonthermal microwave source archived in Nobeyama Radioheliograph data. We analyzed a flare event (an M-class flare on 2014 October 22) showing cyclical microwave brightenings at the two footpoint regions. Assuming that the brightenings were caused by the accelerated electrons, we approximated the velocity parallel to the magnetic field of the accelerated electrons as 77,000 and 90,000 km/s. The estimated pitch angle of the accelerated electrons is 69-80 degrees and the size of the loss cone at the footpoint (estimated from the magnetic field strength in the nonlinear force-free field model) is approximately 43 degrees. Most of the accelerated electrons could be reflected at the footpoint region. This feature can be interpreted as brightenings produced by bouncing motion of the accelerated electrons.

We revisit the theoretical priors used for inferring Dark Energy (DE) parameters. Any DE model must have some form of a tracker mechanism such that it behaved as matter or radiation in the past. Otherwise, the model is fine-tuned. We construct a model-independent parametrization that takes this prior into account and allows for a relatively sudden transition between radiation/matter to DE behavior. We match the parametrization with current data, and deduce that the adiabatic and effective sound speeds of DE play an important role in inferring the cosmological parameters. We find that there is a preferred transition redshift of $1+z\simeq 29-30$, and some reduction in the Hubble and Large Scale Structure tensions.

Future detection of high-redshift gamma-ray bursts (GRBs) will be an important tool for studying the early Universe. Fast and accurate redshift estimation for detected GRBs is key for encouraging rapid follow-up observations by ground- and space-based telescopes. Low-redshift dusty interlopers pose the biggest challenge for GRB redshift estimation using broad photometric bands, as their high extinction can mimic a high-redshift GRB. To assess false alarms of high-redshift GRB photometric measurements, we simulate and fit a variety of GRBs using phozzy, a simulation code developed to estimate GRB photometric redshifts, and test the ability to distinguish between high- and low-redshift GRBs when using simultaneously observed photometric bands. We run the code with the wavelength bands and instrument parameters for the Photo-z Infrared Telescope (PIRT), an instrument designed for the Gamow mission concept. We explore various distributions of host galaxy extinction as a function of redshift, and their effect on the completeness and purity of a high-redshift GRB search with the PIRT. We find that for assumptions based on current observations, the completeness and purity range from $\sim 82$ to $88\%$ and from $\sim 84$ to $>99\%$, respectively. For the priors optimized to reduce false positives, only $\sim 0.6\%$ of low-redshift GRBs will be mistaken as a high-redshift one, corresponding to $\sim 1$ false alarm per 500 detected GRBs.

We present a new FRIED grid of mass loss rates for externally far-ultraviolet (FUV) irradiated protoplanetary discs. As a precursor to the new grid, we also explore the microphysics of external photoevaporation, determining the impact of polycyclic aromatic hydrocarbon (PAH) abundance, metallicity, coolant depletion (via freeze out and radial drift) and grain growth (depletion of small dust in the outer disc) on disc mass loss rates. We find that metallicity variations typically have a small effect on the mass loss rate, since the impact of changes in heating, cooling and optical depth to the disc approximately cancel out. The new FRIED grid therefore focuses on i) expanding the basic physical parameter space (disc mass, radius, UV field, stellar mass) ii) on enabling variation of the the PAH abundance and iii) including an option for grain growth to have occurred or not in the disc. What we suggest is the fiducial model is comparable to the original FRIED grid. When the PAH-to-dust ratio is lower, or the dust in the wind more abundant, the mass loss rate can be substantially lower. We demonstrate with a small set of illustrative disc evolutionary calculations that this in turn can have a significant impact on the disc mass/radius/ evolution and lifetime.

The hydrodynamic exchange of a protoplanet's envelope material with the background protoplanetary disk has been proposed as one mechanism to account for the diversity of observed planet envelopes which range in mass fractions of ~1% for super-Earths to ~90% for giants. Here we present and analyze 3D radiation-hydrodynamics models of protoplanet envelopes to understand how the exchange of mass and energy between the protoplanet and background disk influences the formation process. Our protoplanet envelope simulations show an exchange of material bringing the outer <0.4Rbondi envelope to steady state. This exchange provides a continuous source of energy, which acts to increase the observed luminosity beyond that inferred from the binding energy liberated from Kelvin-Helmholtz contraction alone -- a finding important for potential protoplanet observations. The inner <0.4Rbondi, on the other hand, appears insulated -- growing in accordance with 1D quasi-static theory. We incorporate these 3D hydrodynamic effects into an extensible 1D framework with a physically motivated three-layer recycling parameterization. Specializing to the case of Jupiter, recycling produces minimal changes to the growth rate with the planet still entering runaway accretion and becoming a gas giant in ~1 Myr. Even in the inner disk (0.1 AU), our 1D models suggest that recycling is not so robust and ubiquitous as to stop all cores from becoming giants. At the same time however, this recycling can delay a runaway phase by an order-of-magnitude depending on the inner disk conditions and core mass.

We revisit the lensing anomaly in the Planck 2018 temperature (TT) data and examine its robustness to frequency selection and additional sky masking. Our main findings are: (1) The phenomenological lensing amplitude parameter, $A_L$, varies with ecliptic latitude, with a $2.9\sigma$ preference for $A_L>1$ near the ecliptic, and $1.0\sigma$ preference near the ecliptic poles, compared to $2.5\sigma$ on the original masks. This behavior is largely or solely from 217 GHz and suggestive of some non-random effect given the Planck scan strategy. (2) The 217 GHz TT data also show a stronger preference for $A_L>1$ than the lower frequencies. The shifts in $A_L$ from 217 GHz with additional Galactic dust masking are too large to be explained solely by statistical fluctuations, indicating some connection with the foreground treatment. Overall, the Planck $A_L$ anomaly does not have a single simple cause. Removing the 217 GHz TT data leaves a $1.8\sigma$ preference for $A_L>1$. The low-multipole ($\ell<30$) TT data contribute to the preference for $A_L>1$ through correlations with $\Lambda$CDM parameters. The 100 and 143 GHz data at $\ell\geq30$ prefer $A_L>1$ at $1.3\sigma$, and this appears robust to the masking tests we performed. The lensing anomaly may impact fits to alternative cosmological models. Marginalizing over $A_L$, optionally applied only to Planck TT spectra, can check this. Models proposed to address cosmological tensions should be robust to removal of the Planck 217 GHz TT data.

Large solar flares occasionally trigger significant space-weather disturbances that affect the technological infrastructures of modern civilization, and therefore require further investigation. Although these solar flares have been monitored by satellite observations since the 1970s, large solar flares occur only infrequently and restrict systematic statistical research owing to data limitations. However, Toyokawa Observatory has operated solar radio observations at low frequencies (at 3.75 and 9.4 GHz) since 1951 and captured the early great flares as solar radio bursts. To estimate the magnitudes of flares that occurred before the start of solar X-ray (SXR) observations with the Geostationary Operational Environmental Satellite (GOES) satellites, we show the relationship between microwave fluxes at 3.75 and 9.4 GHz and X-ray fluxes of flares that occurred after 1988. In total, we explored 341 solar flares observed with the Nobeyama Radio Polarimeters and Toyokawa Observatory from 1988-2014 and compared them with the SXR observations recorded by the GOES satellites. The correlation coefficient was approximately 0.7. Therefore, the GOES X-ray class can be estimated from the peak flux at 3.75 and 9.4 GHz with a large variance and an error of factor of 3 (1 sigma). Thus, for the first time, we quantitatively estimated the light curves of two early solar flares observed in 1956 February by the Toyokawa solar radio observations using the relationship between SXR thermal radiation and microwave nonthermal radiation (Neupert, 1968, ApJ, 153, 59).

We investigate the effect of the jet's immediate surroundings on the non-thermal synchrotron emission and its polarization properties. The ambient medium is equipped with a turbulent magnetic field, which is compressed and amplified by the jets as they progress. This leads to high polarization at the forward shock surface. The randomness in the magnetic polarities of the external fields in the shocked ambient medium (SAM) results in vector cancellation of the polarized components from the jet, thereby causing depolarization of the radiation from the cocoon. We find that due to the slow decay of the fields in the SAM, such depolarization by the fields with large correlation lengths is more prominent when compared to the small-scale fields. Also, the low-power jets, which have magnetic fields comparable in strength to those in the SAM, are more severely affected by the SAM's depolarizing effect, than the high-power ones. The turbulent backflows in the cocoon, as well as the shearing of fields near the contact discontinuity, strengthen the poloidal component in the jet. This causes internal depolarization due to the cancellation of the orthogonally polarized components along the Line of Sight as the field transitions from ordered toroidal to poloidal. The synchrotron maps display high-emission filaments in the cocoon with magnetic fields aligned along them. The kink instability leads to the wiggling motion of the jet's spine, resulting in hotspot complexes in low-power sources.

We investigate the mass-metallicity relation for galaxies in the Abell cluster AC114 from 7 hours of VIMOS/MR data collected at the ESO-VLT telescope in 2009. The dynamical analysis completed in our previous paper allowed us to select cluster members, whose spectra are here analyzed with stellar population synthesis models. Active and passive galaxies are identified based on the presence/absence of the [\ion{O}{II}]\lambda3727, [\ion{O}{III}]\lambda\lambda4959,5007 and/or H\beta emission lines, depending on the galaxy redshift. We find that active galaxies have lower average masses than passive ones, and have lower average metallicities. The mass-metallicity relation (MZR) of the cluster is found to be steeper than that for galaxies in the local universe.

The Joint Experiment Missions for Extreme Universe Observatory comprises a collection of complementary missions dedicated to pioneering technologies and techniques for a future space-based multi-messenger observatory which will have sufficient sensitivity and exposure to measure properties of extremely rare ultra-high energy (E>50 EeV) cosmic rays and very high energy (E>100 PeV) neutrinos. Here we describe a general-purpose software framework designed to facilitate detailed simulation and reconstruction of events observed by the various missions using both detection of fluorescence and Cherenkov light produced when cosmic ray or neutrino-induced extensive air showers traverse Earth's atmosphere. The software builds on a framework developed by the Pierre Auger Collaboration. We describe the techniques used to organize contributions from numerous collaborators, manage an abundance of configuration information, and provide simple access to time-dependent detector and atmospheric information. We also explain how we support a multitude of computing platforms, provide fast installation and maintain the broad testing coverage required for stability of the large and heterogeneous code base. We provide a few examples of simulated and reconstructed data gathered by some of the JEM-EUSO missions, including the EUSO-SPB2 instrument.

We searched the Gaia DR3 database for ultramassive white dwarfs with kinematics consistent with having escaped the nearby Hyades open cluster, identifying three such candidates. Two of these candidates have masses estimated from Gaia photometry of approximately 1.1 solar masses; their status as products of single stellar evolution that have escaped the cluster was deemed too questionable for immediate follow-up analysis. The remaining candidate has an expected mass >1.3 solar masses, significantly reducing the probability of it being an interloper. Analysis of follow-up Gemini GMOS spectroscopy for this source reveals a non-magnetized hydrogen atmosphere white dwarf with a mass and age consistent with having formed from a single star. Assuming a single-stellar evolution formation channel, we estimate a 97.8% chance that the candidate is a true escapee from the Hyades. With a determined mass of 1.317 solar masses, this is potentially the most massive known single-evolution white dwarf and is by far the most massive with a strong association with an open cluster.

Nearby radio galaxies (RGs) of Fanaroff-Riley Class I (FR-I) are considered as possible sites for the production of observed ultra-high-energy cosmic rays (UHECRs). Among those, some exhibit blazar-like inner jets, while others display plume-like structures. We reproduce the flow dynamics of FR-I jets using relativistic hydrodynamic simulations. Subsequently, we track the transport and energization of cosmic ray (CR) particles within the simulated jet flows using Monte Carlo simulations. The key determinant of flow dynamics is the mean Lorentz factor of the jet-spine flow, $\langle\Gamma\rangle_{\rm{spine}}$. When $\langle\Gamma\rangle_{\rm{spine}}\gtrsim$ several, the jet spine remains almost unimpeded, but for $\langle\Gamma\rangle_{\rm{spine}}\lesssim$ a few, substantial jet deceleration occurs. CRs gain energy mainly through diffusive shock acceleration for $E\lesssim1$ EeV and shear acceleration for $E\gtrsim1$ EeV. The time-asymptotic energy spectrum of CRs escaping from the jet can be modeled by a double power law, transitioning from $\sim E^{-0.6}$ to $\sim E^{-2.6}$ around a break energy, $E_{\rm{break}}$, with an exponential cutoff at $E_{\rm{break}}\langle\Gamma\rangle_{\rm{spine}}^2$. $E_{\rm{break}}$ is either determined by the Hillas confinement condition or constrained by spatial diffusion leading to particle escape from the cocoon. The spectral slopes primarily arise from relativistic shear acceleration and the confinement-escape processes within the cocoon. The exponential cutoff is determined by non-gradual shear acceleration that boosts the energy of high-energy CRs by a factor of $\sim \langle\Gamma\rangle_{\rm{spine}}^2$. We suggest that the model spectrum derived in this work could be employed to investigate the impact of RGs on the observed population of UHECRs.

In this series of papers, we present new methods of frequency- and time-dependent instrumental polarization calibration for Very Long Baseline Interferometry (VLBI). In most existing calibration tools and pipelines, it has been assumed that instrumental polarization is constant over frequency within the instrument bandwidth and over time. The assumption is not always true and may prevent an accurate calibration, which can result in degradation of the quality of linear polarization images. In this paper, we present a method of frequency-dependent instrumental polarization calibration that is implemented in GPCAL, a recently developed polarization calibration pipeline. The method is tested using simulated data sets generated from real Very Long Baseline Array (VLBA) data. We present the results of appyling the method to real VLBA data sets observed at 15 and 43 GHz. We were able to eliminate significant variability in cross-hand visibilities over frequency that is caused by frequency-dependent instrumental polarization. As a result of the calibration, linear polarization images were slightly to modestly improved as compared to those obtained without frequency-dependent instrumental polarization calibration. We discuss the reason for the minor impact of frequency-dependent instrumental polarization calibration on existing VLBA data sets and prospects for applying the method to future VLBI data sets, which are expected to provide very large bandwidths.

We present a new method of time-dependent instrumental polarization calibration for Very Long Baseline Interferometry (VLBI). This method has been implemented in the recently developed polarization calibration pipeline GPCAL. Instrumental polarization, also known as polarimetric leakage, is a direction-dependent effect, and it is not constant across the beam of a telescope. Antenna pointing model accuracy is usually dependent on time, resulting in off-axis polarimetric leakages that can vary with time. The method is designed to correct for the off-axis leakages with large amplitudes that can severely degrade linear polarization images. Using synthetic data generated based on real Very Long Baseline Array (VLBA) data observed at 43 GHz, we evaluate the performance of the method. The method was able to reproduce the off-axis leakages assumed in the synthetic data, particularly those with large amplitudes. The method has been applied to two sets of real VLBA data and the derived off-axis leakages show very similar trends over time for pairs of nearby sources. Furthermore, the amplitudes of the off-axis leakages are strongly correlated with the antenna gain correction factors. The results demonstrate that the method is capable of correcting for the off-axis leakages present in VLBI data. By calibrating time-dependent instrumental polarization, the rms-noise levels of the updated linear polarization images have been significantly reduced. The method is expected to substantially enhance the quality of linear polarization images obtained from existing and future VLBI observations.

We present the transmission spectrum of the original transiting hot Jupiter HD\,209458b from 2.3 -- 5.1\,$\mu$m as observed with the NIRCam instrument on the James Webb Space Telescope (JWST). Previous studies of HD\,209458b's atmosphere have given conflicting results on the abundance of H$_2$O and the presence of carbon- and nitrogen-bearing species, which have significant ramifications on the inferences of the planet's metallicity (M/H) and carbon-to-oxygen (C/O) ratio. We detect strong features of H$_2$O and CO$_2$ in the JWST transmission spectrum, which when interpreted using a retrieval that assumes thermochemical equilibrium and fractional grey cloud opacity yields $4^{+5}_{-2}$ $\times$ solar metallicity and C/O = $0.08^{+0.09}_{-0.05}$. The derived metallicity is consistent with the atmospheric metallicity-planet mass trend observed in solar gas giants. The low C/O ratio suggests that this planet has undergone significant contamination by evaporating planetesimals while migrating inward. We are also able to place upper limits on the abundances of CH$_4$, C$_2$H$_2$ and HCN of log($\chi_{\mathrm{CH}_4}$) = -4.4, log($\chi_{\mathrm{C}_2\mathrm{H}_2}$) = -5.3, and log($\chi_{\mathrm{HCN}}$) = -5.5, which are in tension with the recent claim of a detection of these species using ground-based cross-correlation spectroscopy. We find that HD\,209458b has a weaker CO$_2$ feature size than WASP-39b when comparing their scale-height-normalized transmission spectra. On the other hand, the size of HD\,209458b's H$_2$O feature is stronger, thus reinforcing the low C/O inference.

We carried out a sensitive survey of C$_2$ and C$_3$ using the EDIBLES data set. We also expanded our searches to C$_4$, C$_5$, and $^{13}$C$^{12}$C isotopologue in the most molecule-rich sightlines. We fit synthetic spectra generated following a physical excitation model to the C$_2$ (2-0) Phillips band to obtain the C$_2$ column density ($N$) as well as the kinetic temperature ($T_\textrm{kin}$) and number density ($n$) of the host cloud. The C$_3$ molecule was measured through its $\tilde{A} - \tilde{X}$ (000-000) electronic origin band system. We simulated the excitation of this band with a double-temperature Boltzmann distribution. We present the largest combined survey of C$_2$ and C$_3$ to date in which the individual transitions can be resolved. In total we detected C$_2$ in 51 velocity components along 40 sightlines, and C$_3$ in 31 velocity components along 27 sightlines. The two molecules are detected in the same velocity components. We find a very good correlation between $N$(C$_2$) and $N$(C$_3$) with Pearson $r = 0.93$ and an average $N$(C$_2$)/$N$(C$_3$) ratio of 15.5$\pm$1.4. A comparison with the behaviour of the C$_2$ DIBs shows that there are no clear differences among sightlines with and without detection of C$_2$ and C$_3$. This is in direct contrast to the better-studied non-C$_2$ DIBs who have reduced strengths in molecule-rich environments. We also identify for the first time the $Q$(2), $Q$(3), and $Q$(4) transitions of the $^{13}$C$^{12}$C (2-0) Phillips band in a stacked average spectrum, and estimate the isotopic ratio of carbon $^{12}$C/$^{13}$C as 79$\pm$8. Our search for the C$_4$ and C$_5$ optical bands was unsuccessful.

We investigate on the role of the halo concentration in the formation of the intra-cluster light (ICL) in galaxy groups and clusters, as predicted by a state-of-art semi-analytic model of galaxy formation, coupled with a set of high-resolution dark matter only simulations. The analysis focuses on how the fraction of ICL correlates with halo mass, concentration and fraction of early-type galaxies (ETGs) in a large sample of groups and clusters with $13.0\leq \log M_{halo} \leq 15.0$. The fraction of ICL follows a normal distribution, a consequence of the stochastic nature of the physical processes responsible for the formation of the diffuse light. The fractional budget of ICL depends on both halo mass (very weakly) until group scales, and concentration (remarkably). More interestingly, the ICL fraction is higher in more concentrated objects, a result of the stronger tidal forces acting in the innermost regions of the haloes where the concentration is the quantity playing the most relevant role. Our model predictions do not show any dependence between the ICL and ETGs fractions and so, we instead suggest the concentration rather than the mass, as recently claimed, to be the main driver of the ICL formation. The diffuse light starts to form in groups via stellar stripping and mergers and later assembled in more massive objects. However, the formation and assembly keep going on group/cluster scales at lower redshift through the same processes, mainly via stellar stripping in the vicinity of the central regions where tidal forces are stronger.

The S254-258 star-forming complex is a place of massive star formation where five OB-stars have created HII regions, visible as optical nebulae, and disrupted the parental molecular gas. In this work, we study the 3D structure of these \HII regions using optical spectroscopy and tunable-filter photometry with the 6-m and 1-m telescopes of the Special Astrophysical Observatory of the Russian Academy of Sciences. We construct maps of the optical extinction, and find that the HII emission is attenuated by neutral material with $2 \leq A_V \leq 5$ mag. The typical electron density in S255, and S257 is $\approx 100$ cm$^{-3}$, with enhancements up to 200 cm$^{-3}$ in their borders, and up to 400 cm$^{-3}$ toward the dense molecular cloud between them, where active star formation is taking place. We show that either a model of a clumpy dense neutral shell, where UV~photons penetrate through and ionize the gas, or a stellar wind, can explain the shell-like structure of the ionized gas. S255 is surrounded by neutral material from all sides, but S257 is situated on the border of a molecular cloud and does not have dense front and rear walls. The compact HII regions S256 and S258 are deeply embedded in the molecular clouds.

Modern imaging atmospheric Cherenkov telescopes have extensively observed young nearby supernova remnants (SNRs), with ages of about 1000 years or less, in the very-high-energy (VHE) gamma-ray band. These efforts resulted in the detection of VHE emission from three young SNRs - Cassiopeia A, Tycho, and SN 1006 - and provided significant evidence for emission from the more distant Kepler's SNR. However, many questions on the production of VHE gamma rays in these remnants remain unanswered. Using detailed physical models for Tycho's SNR based on the CR-hydro-NEI code and physically motivated models for the other young nearby remnants, we simulated observations with the Cherenkov Telescope Array (CTA) of these gamma-ray sources. We highlight properties of these remnants accessible for investigation with future CTA observations and discuss which questions are expected to be answered.

The effect of stellar multiplicity on planetary architecture and orbital dynamics provides an important context for exoplanet demographics. We present a volume-limited catalog up to 300 pc of 66 stars hosting planets and planet candidates from Kepler, K2 and TESS with significant Hipparcos-Gaia proper motion anomalies, which indicate the presence of companions. We assess the reliability of each transiting planet candidate using ground-based follow-up observations, and find that the TESS Objects of Interest (TOIs) with significant proper motion anomalies show nearly four times more false positives due to Eclipsing Binaries compared to TOIs with marginal proper motion anomalies. In addition, we find tentative evidence that orbital periods of planets orbiting TOIs with significant proper motion anomalies are shorter than those orbiting TOIs without significant proper motion anomalies, consistent with the scenario that stellar companions can truncate planet-forming disks. Furthermore, TOIs with significant proper motion anomalies exhibit lower Gaia differential velocities in comparison to field stars with significant proper motion anomalies, suggesting that planets are more likely to form in binary systems with low-mass substellar companions or stellar companions at wider separation. Finally, we characterize the three-dimensional architecture of LTT 1445 ABC using radial velocities, absolute astrometry from Gaia and Hipparcos, and relative astrometry from imaging. Our analysis reveals that LTT 1445 is a nearly flat system, with a mutual inclination of 2.88 deg between the orbit of BC around A and that of C around B. The coplanarity may explain why multiple planets around LTT 1445 A survive in the dynamically hostile environment of this system.

We present detailed analyses of updated eclipse timing diagrams for 32 contact binary merger candidates in the Galactic bulge. The photometric data was obtained from 2016 to 2021 using the Korea Microlensing Telescope Network (KMTNet) with the 1.6 m telescopes located at three southern sites (CTIO, SAAO, and SSO). The times of minimum lights were determined by applying the binary star model to full light curves created at half-year intervals from the observations. The orbital period variations of the binary systems were analyzed using the $O-C$ diagrams from our new timings with the others published in the literature (Hong et al.), which are based on the OGLE observations from 2001 to 2015. As results, the orbital periods and period decreasing rates of 32 binary systems were located to be in the ranges of 0.370$-$1.238 days and from $-3.0$ to $-13.1\times10^{-6}$ day yr$^{-1}$, respectively. Out of these stars, 24 systems show a combination effect of a parabola and a light travel time caused by a third body and their outer orbital periods are in the range of 9.1$-$26.5 yr, respectively. We propose that all of our merger candidates need additional monitoring observations to study a luminous red nova (LRN) progenitor.

The latest entry in the jetted active galactic nuclei (AGN) family is the Fanaroff-Riley type 0 (FR0) radio galaxies. They share several observational characteristics, e.g., nuclear emission and host galaxy morphology, with FR I sources; however, they lack extended, kiloparsec-scale radio structures, which are the defining features of canonical FR I and II sources. Here we report the identification of 7 gamma-ray emitting AGN as FR0 radio sources by utilizing the high-quality observations delivered by ongoing multi-wavelength wide-field sky surveys, e.g., Very Large Array Sky Survey. The broadband observational properties of these objects are found to be similar to their gamma-ray undetected counterparts. In the gamma-ray band, FR0 radio galaxies exhibit spectral features similar to more common FR I and II radio galaxies, indicating a common gamma-ray production mechanism and the presence of misaligned jets. Although the parsec-scale radio structure of FR0s generally exhibits a wide range, with about half having emission on opposite sides of the core, the gamma-ray detected FR0s tend to have dominant cores with core-jet structures. We conclude that dedicated, high-resolution observations are needed to unravel the origin of relativistic jets in this enigmatic class of faint yet numerous population of compact radio sources.

Observations reveal protoplanetary discs being perturbed by flyby candidates. We simulate a scenario where an unbound perturber, i.e., a flyby, undergoes an inclined grazing encounter, capturing material and forming a second-generation protoplanetary disc. We run $N$--body and three-dimensional hydrodynamical simulations of a parabolic flyby grazing a particle disc and a gas-rich protoplanetary disc, respectively. In both our $N$--body and hydrodynamic simulations, we find that the captured, second-generation disc forms at a tilt twice the initial flyby tilt. This relationship is robust to variations in the flyby's tilt, position angle, periastron, and mass. We extend this concept by also simulating the case where the flyby has a disc of material prior to the encounter but we do not find the same trend. An inclined disc with respect to the primary disc around a misaligned flyby is tilted by a few degrees, remaining close to its initial disc tilt. Therefore, if a disc is present around the flyby before the encounter, the disc may not tilt up to twice the perturber tilt depending on the balance between the angular momentum of the circumsecondary disc and captured particles. In the case where the perturber has no initial disc, analyzing the orientation of these second-generation discs can give information about the orbital properties of the flyby encounter.

Wavelets are waveform functions that describe transient and unstable variations, such as noises. In this work, we study the advantages of discrete and continuous wavelet transforms (DWT and CWT) of microlensing data to denoise them and extract their planetary signals and intrinsic pulsations hidden by noises. We first generate synthetic microlensing data and apply wavelet denoising to them. For these simulated microlensing data with ideally Gaussian nosies based on the OGLE photometric accuracy, denoising with DWT reduces standard deviations of data from real models by $0.044$-$0.048$ mag. The efficiency to regenerate real models and planetary signals with denoised data strongly depends on the observing cadence and decreases from $37\%$ to $0.01\%$ by worsening cadence from $15$ min to $6$ hrs. We then apply denoising on $100$ microlensing events discovered by the OGLE group. On average, wavelet denoising for these data improves standard deviations and $\chi^{2}_{\rm n}$ of data with respect to the best-fitted models by $0.023$ mag, and $1.16$, respectively. The best-performing wavelets (based on either the highest signal-to-noise ratio's peak ($\rm{SNR}_{\rm{max}}$), or the highest Pearson's correlation, or the lowest Root Mean Squared Error (RMSE) for denoised data) are from 'Symlet', and 'Biorthogonal' wavelets families in simulated, and OGLE data, respectively. In some denoised data, intrinsic stellar pulsations or small planetary-like deviations appear which were covered with noises in raw data. However, through DWT denoising rather flattened and wide planetary signals could be reconstructed than sharp signals. CWT and 3D frequency-power-time maps could advise about the existence of sharp signals.

The evolution of accreting X-ray binary systems is closely coupled to the properties of their donor stars. As a result, we can constrain the evolutionary track a system is by establishing the nature of its donor. Here, we present far-UV spectroscopy of the transient neutron-star low-mass X-ray binary Swift J1858 in three different accretion states (low-hard, high-hard and soft). All of these spectra exhibit anomalous N\,{\sc v}, C\,{\sc iv}, Si\,{\sc iv} and He\,{\sc ii} lines, suggesting that its donor star has undergone CNO processing. We also determine the donor's effective temperature, $T_{d} \simeq 5700$~K, and radius, $R_d \simeq 1.7~R_{\odot}$, based on photometric observations obtained during quiescence. Lastly, we leverage the transient nature of the system to set an upper limit of $\dot{M}_{\rm acc} \lesssim 10^{-8.5}~M_{\odot}~yr^{-1}$ on the present-day mass-transfer rate. Combining all these with the orbital period of the system, $P_{\rm orb} = 21.3$~hrs, we search for viable evolution paths. The initial donor masses in the allowed solutions span the range $1~M_{\odot} \lesssim M_{d,i} \lesssim 3.5~M_{\odot}$. All but the lowest masses in this range are consistent with the strong CNO-processing signature in the UV line ratios. The present-day donor mass in the permitted tracks are $0.5~M_{\odot}\lesssim M_{d,obs} \lesssim 1.3~M_{\odot}$, higher than suggested by recent eclipse modelling. Since $P_{\rm orb}$ is close to the so-called bifurcation period, both converging and diverging binary tracks are permitted. If Swift J1858 is on a converging track, it will end its life as an ultra-compact system with a sub-stellar donor star.

Mrk 71 is a low metallicity (Z = 0.16 Z_sun) starburst region in the local dwarf galaxy NGC 2366, hosting two super star clusters (SSCs A and B), and is recognized as a Green Pea (GP) analog with SSC A responsible for the GP properties. We present STIS and FOS far-ultraviolet (FUV) spectra of the embedded SSC Mrk 71-A obtained with the Hubble Space Telescope (HST). The STIS FUV spectrum shows the characteristic features of very massive stars (VMS, masses > 100 M_sun) and we derive an age of 1+/-1 Myr by comparison with the Charlot & Bruzual suite of spectral population synthesis models with upper mass limits of 300 and 600 M_sun. We compare the STIS spectrum with all known SSC spectra exhibiting VMS signatures: NGC 5253-5, R136a, NGC 3125-A1 and the z = 2.37 Sunburst cluster. We find that the cluster mass-loss rates and wind velocities, as characterized by the C IV P Cygni profiles and the He II emission line strengths, are very similar over Z = 0.16 to 0.4 Z_sun. This agrees with predictions that the optically thick winds of VMS will be enhanced near the Eddington limit and show little metallicity dependence. We find very strong damped Lyman-alpha absorption with log N(H I) = 22.2 cm-2 associated with Mrk 71-A. We discuss the natal environment of this young SSC in terms of radiatively-driven winds, catastrophic cooling and recent models where the cluster is surrounded by highly pressurized clouds with large neutral columns.

Context. G189.6+03.3 and IC443 are two examples of supernova remnants located in a region rich of gas and dust, spatially close to the HII region S249. So far, the actual shape of IC443 is believed to be given by the past action of multiple supernova explosions, while a third unrelated might have originated G189.6+03.3. Aims. If the IC443 nebula has been extensively observed in several bands, in opposite there is an almost complete lack of observations on the nearby and much weaker supernova remnant G189.6+03.3, discovered in 1994 with ROSAT. Given the relatively large extent of this second remnant, the new dataset provided by the X-ray telescope eROSITA onboard the Spectrum Roentgen Gamma (SRG) mission gives a unique opportunity to characterize it more in depth. Methods. We provide a full spectral characterization of G189.6+03.3 emission for the first time, together with new images covering the whole remnant. Since one of the leading hypothesis is that its emission partially overlaps with the emission of IC443, we test this scenario dividing the remnant in several regions from which we extracted the spectra. Results. The new X-ray images provided by eROSITA show an elongated structure. Together with the detection of supersolar abundances of O, Mg, Ne and Si and subsolar abundance of Fe, these features could be an indication of a faint supernova explosion. The X-ray spectra also highlight the presence of a 0.7 keV plasma component across all the regions together with a column density almost uniform. Conclusions. The ubiquitous presence of the 0.7 keV plasma component is a strong indication for G189.6+03.3 overlapping completely with IC443. We propose the progenitors of G189.6+03.3 and IC443 could have been hosted in a binary or multiple system, originating two explosions at different times in different positions.

This study presents the first millimeter continuum mapping observations of two nearby galaxies, the starburst spiral galaxy NGC2146 and the dwarf galaxy NGC2976, at 1.15 mm and 2 mm using the NIKA2 camera on the IRAM 30m telescope, as part of the Guaranteed Time Large Project IMEGIN. These observations provide robust resolved information about the physical properties of dust in nearby galaxies by constraining their FIR-radio SED in the millimeter domain. After subtracting the contribution from the CO line emission, the SEDs are modeled spatially using a Bayesian approach. Maps of dust mass surface density, temperature, emissivity index, and thermal radio component of the galaxies are presented, allowing for a study of the relations between the dust properties and star formation activity (using observations at 24$\mu$m as a tracer). We report that dust temperature is correlated with star formation rate in both galaxies. The effect of star formation activity on dust temperature is stronger in NGC2976, an indication of the thinner interstellar medium of dwarf galaxies. Moreover, an anti-correlation trend is reported between the dust emissivity index and temperature in both galaxies.

Reconstructed tracks of muons produced in neutrino interactions provide the precise probe for the neutrino direction. Therefore, track-like events are a powerful tool to search for neutrino point sources. Recently, Baikal-GVD has demonstrated the first sample of low-energy neutrino candidate events extracted from the data of the season 2019 in a so-called single-cluster analysis - treating each cluster as an independent detector. In this paper, the extension of the track-like event analysis to a wider data set is discussed and the first high-energy track-like events are demonstrated. The status of multi-cluster track reconstruction and that of the event analysis are also discussed.

Gravitational-wave (GW) interferometers are able to detect a change in distance of $\sim$ 1/10,000th the size of a proton. Such sensitivity leads to large appearance rates of non-Gaussian transient noise bursts in the main detector strain, also known as glitches. These glitches come in a wide range of frequency-amplitude-time morphologies and are caused by environmental or instrumental processes, hindering searches for all sources of gravitational waves. Current approaches for their identification use supervised models to learn their morphology in the main strain, but do not consider relevant information provided by auxiliary channels that monitor the state of the interferometers nor provide a flexible framework for novel glitch morphologies. In this work, we present an unsupervised algorithm to find anomalous glitches. We encode a subset of auxiliary channels from LIGO Livingston in the fractal dimension, a measure for the complexity of the data, and learn the underlying distribution of the data using an auto-encoder with periodic convolutions. In this way, we uncover unknown glitch morphologies, and overlaps in time between different glitches and misclassifications. This led to the discovery of anomalies in $6.6 \%$ of the input data. The results of this investigation stress the learnable structure of auxiliary channels encoded in fractal dimension and provide a flexible framework to improve the state-of-the-art of glitch identification algorithms.

We present a novel approach to address dust production by low- and intermediate-mass stars. We study the asymptotic giant branch (AGB) phase, during which the formation of dust takes place, from the perspective of post-AGB and planetary nebula (PN) evolutionary stage. Using results from stellar evolution and dust formation modelling, we interpret the spectral energy distribution of carbon-dust-rich sources currently evolving through different evolutionary phases, believed to descend from progenitors of similar mass and chemical composition. Comparing the results of different stages along the AGB to PNe transition, we can provide distinct insights on the amount of dust and gas released during the very late AGB phases. While the post-AGB traces the history of dust production back to the tip of the AGB phase, investigating the PNe is important to reconstruct the mass-loss process experienced after the last thermal pulse. The dust surrounding the post-AGB was formed soon after the tip of the AGB. The PNe dust-to-gas ratio is $\sim10^{-3}$, 2.5 times smaller than what expected for the same initial mass star during the last AGB interpulse, possibly suggesting that dust might be destroyed during the PN phase. Measuring the amount of dust present in the nebula can constrains the capacity of the dust to survive the central star heating.

A quantitative derivation of the intrinsic properties of galaxies related to their fundamental building blocks, gas, dust and stars is essential for our understanding of galaxy evolution. A fully self-consistent derivation of these properties can be achieved with radiative transfer (RT) methods that are constrained by panchromatic imaging observations. Here we present an axi-symmetric RT model of the UV-optical-FIR/submm spectral and spatial energy distribution of the face-on spiral galaxy M51. The model reproduces reasonably well the azimuthally averaged radial profiles derived from the imaging data available for this galaxy, from GALEX, SDSS, 2MASS, Spitzer and Herschel. We model the galaxy with three distinct morphological components: a bulge, an inner disc and a main disc. We derive the length parameters of the stellar emissivity and of the dust distribution. We also derive the intrinsic global and spatially resolved parameters of M51. We find a faint \lq\lq outer disc\rq\rq\ bridging M51 with its companion galaxy M51b. Finally, we present and discuss an alternative model, with dust properties that change within the galaxy.

More than twenty papers on the development of this model have been published in Monthly Notices of the Royal Astronomical Society from 2010 to the present. Whilst some contain work that is essential for the development of the model, others are less so. This present paper is a summary, citing only the former set of papers and the observational phenomena to which the model relates.

The simplest cosmological model ($\Lambda$CDM) is well-known to suffer from the Hubble tension, namely an almost $5 \sigma$ discrepancy between the (model-based) early-time determination of the Hubble constant $H_0$ and its late-time (and model-independent) determination. To circumvent this, we introduce an additional energy source that varies with the redshift as $(1 + z)^n$, where $0 < n < 3$, and test it against the Pantheon Compilation of Type Ia Supernovae as well as the CMBR observations (at $z \approx 1100$). The deduced $H_0$ is now well-consistent with the value obtained from local observations of Cepheid variables. Suggesting a non-zero value for the curvature density parameter, positive (negative) for $n > 2$ ($n < 2$), the resolution is also consistent with the BAO data.

Fallback rate of debris after a partial tidal disruption event of a star with an intermediate mass black hole (IMBH) might provide important signatures of such black holes, compared to supermassive ones. Here using smoothed particle hydrodynamics methods, we provide a comprehensive numerical analysis of this phenomenon. We perform numerical simulations of single partial tidal disruptions of solar mass white dwarfs in parabolic orbits, with a non-spinning $10^3M_{\odot}$ IMBH for various values of the impact parameter, and determine the core mass fractions and fallback rates of debris into the IMBH. For supermassive black holes, in a full disruption processes, it is known that the late time fallback rate follows a power law $t^{-5/3}$, whereas for partial disruptions, such a rate has been recently conjectured to saturate to a steeper power law $t^{-9/4}$, independent of the mass of the remnant core. We show here that for IMBHs, partial disruptions significantly alter this conclusion. That is, the fallback rate at late times do not asymptote to a $t^{-9/4}$ power law, and this rate is also a strong function of the core mass. We derive a robust formula for the late time fallback rate as a function of the core mass fraction, that is independent of the white dwarf mass, as we verify numerically by varying the mass of the white dwarf.

Fe II emission is a well-known contributor to the UV spectra of active galactic nuclei, and the modeling of this part may affect the results obtained for the MgII emission which is one of the lines used for black hole mass measurement and for cosmological applications. We test different Fe II emission models when modeling the UV emission of the intermediate-redshift quasar HE 0413-4031 with the aim of seeing how the use of a specific template affects the MgII line properties and the measurement of the MgII and UV FeII time delays with respect to the continuum. We use the 11-year monitoring of the selected quasar HE 0413-4031 with the South African Large Telescope (SALT), and we supplement this monitoring with the near-IR spectrum taken with the SOAR telescope which gave access to the H$\beta$ and [OIII] emission lines at the rest frame and allowed for a precise measurement of the redshift. A new redshift determination ($z=1.39117 \pm 0.00017$) using [OIII] lines gave a very different value than the previous determination based only on the UV FeII pseudocontinuum ($z=1.3764$). It favors a different decomposition of the spectrum into Mg II and UV Fe II emissions. The time delay of the Mg II emission ($224^{+21}_{-23}$ days) is not significantly affected. The rest-frame UV FeII time delay ($251^{+9}_{-7}$ days) is consistent with the best-fit FeII FWHM of $4200\,{\rm km/s}$, and hence the FeII-emitting material is more distant than MgII-emitting gas in HE 0413-4031 by 0.023 pc (4700 AU). Moreover, the velocity shift of both Mg II and UV Fe II lines with respect to the systemic redshift is now rather low, below 300 km s$^{-1}$. We construct an updated MgII radius-luminosity ($R-L$) relation from 194 sources, which is flatter than the UV FeII, optical FeII, and H$\beta$ $R-L$ relations. We see a need to create better Fe II templates using the newest version of the code CLOUDY.

The classification of the cosmic web into different environments is both a tool to study in more detail the formation of halos and galaxies via the link between their properties and the large-scale environment and as a class of objects whose statistics contain cosmological information. In this paper, we present an analytical framework to compute the probability of the different environments in the cosmic web based on the T-web formalism that classifies structures in four different classes (voids, walls, filaments, knots) by studying the eigenvalues of the tidal tensor (Hessian of the gravitational potential). This method relies on studying the eigenvalues of the tidal tensor with respect to a given threshold and thus requires the knowledge of the JPDF of those eigenvalues. We perform a change of variables in terms of minimally correlated rotational invariants and we study their distribution in the linear regime of structure formation, and in the quasi-linear regime with the help of a Gram-Charlier expansion and tree-order Eulerian perturbation theory. This expansion allows us to predict the probability of the different environments in the density field at a given smoothing scale as a function of the chosen threshold and redshift. We check the validity of our predictions by comparing those predictions to measurements made in the N-body Quijote simulations. We notably find that scaling the threshold value with the non-linear amplitude of fluctuations allows us to capture almost entirely the redshift evolution of the probability of the environments, even if we assume that the density field is Gaussian (corresponding to the linear regime of structure formation). We also show that adding mild non-Gaussian corrections in the form of third-order cumulants of the field provides even more precise predictions for cosmic web abundances up to scales as small as ~5 Mpc/h and redshifts down to z~0.

We study a mechanism of generating the trispectrum (4-point correlation) of curvature perturbation through the dynamics of a spectator axion field and U(1) gauge field during inflation. Owing to the Chern-Simons coupling, only one helicity mode of gauge field experiences a tachyonic instability and sources scalar perturbations. Sourced curvature perturbation exhibits parity-violating nature which can be tested through its trispectrum. We numerically compute parity-even and parity-odd component of the sourced trispectrum. It is found that the ratio of parity-odd to parity-even mode can reach O(10%) in an exact equilateral momentum configuration. We also investigate a quasi-equilateral shape where only one of the momenta is slightly longer than the other three, and find that the parity-odd mode can reach, and more interestingly, surpass the parity-even one. This may help us to interpret a large parity-odd trispectrum signal extracted from BOSS galaxy-clustering data.

We present a near-IR survey of the Trapezium Cluster and inner Orion Nebula using the NASA/ESA/CSA James Webb Space Telescope. The survey with the NIRCam instrument covers 10.9 x 7.5 arcminutes (~1.25 x 0.85 pc) in twelve wide-, medium-, and narrow-band filters from 1-5 microns and is diffraction-limited at all wavelengths, providing a maximum spatial resolution of 0.063 arcsec at 2 microns, corresponding to ~25 au at Orion. The suite of filters chosen was designed to address a number of scientific questions including the form of the extreme low-mass end of the IMF into the planetary-mass range to 1 Jupiter mass and below; the nature of ionised and non-ionised circumstellar disks and associated proplyds in the near-IR with a similar resolution to prior HST studies; to examine the large fragmented outflow from the embedded BN-KL region at very high resolution and fidelity; and to search for new jets and outflows from young stars in the Trapezium Cluster and the Orion Molecular Cloud 1 behind. In this paper, we present a description of the design of the observational programme, explaining the rationale for the filter set chosen and the telescope and detector modes used to make the survey; the reduction of the data using the JWST pipeline and other tools; the creation of large colour mosaics covering the region; and an overview of the discoveries made in the colour images and in the individual filter mosaics. Highlights include the discovery of large numbers of free-floating planetary-mass candidates as low as 0.6 Jupiter masses, a significant fraction of which are in wide binaries; new emission phenomena associated with the explosive outflow from the BN-KL region; and a mysterious "dark absorber" associated with a number of disparate features in the region, but which is seen exclusively in the F115W filter. Further papers will examine those discoveries and others in more detail.

With the continuous improvement in the precision of exoplanet observations, it has become feasible to probe for subtle effects that can enable a more comprehensive characterization of exoplanets. A notable example is the tidal deformation of ultra-hot Jupiters by their host stars, whose detection can provide valuable insights into the planetary interior structure. In this work, we extend previous research on modeling deformation in transit light curves by proposing a simple approach to account for tidal deformation in phase curves. The planetary shape is modeled as a function of the second fluid Love number for radial deformation $h_{2f}$. We show that the effect of tidal deformation manifests across the full orbit of the planet as its projected area varies with phase, thereby allowing us to better probe the planet's shape in phase curves than in transits. Comparing the effects and detectability of deformation by different space-based instruments, we find that the effect of deformation is more prominent in infrared observations where the phase curve amplitude is the largest. A single JWST phase curve observation of a deformed planet, such as WASP-12b, can allow up to 17$\sigma$ measurement of $h_{2f}$ compared to 4$\sigma$ from transit-only observation. Such high precision $h_{2f}$ measurement can constrain the core mass of the planet to within 19\% of the total mass, thus providing unprecedented constraints on the interior structure. Due to the lower phase curve amplitudes in the optical, the other instruments provide $\leq4\sigma$ precision on $h_{2f}$ depending on the number of phase curves observed. We also find that detecting deformation from infrared phase curves is less affected by uncertainty in limb darkening, unlike detection in transits. Finally, the assumption of sphericity when analyzing the phase curve of deformed planets can lead to biases in several system parameters

A nearly 11-day delayed very-high-energy(VHE) activity compared to the Fermi-LAT flare from quasar 3C 279 was reported by H.E.S.S. on 28 January 2018. 3C 279 has long been considered a candidate site for particle acceleration; hence such events may embed information about the high-energy phenomena. We propose the production channel being leptonic for the multi-wavelength flare, UV-Optical-Xrays-$\gamma$-rays, whereas the delayed VHE activity originated from the proton synchrotron. Our model requires the magnetic field to be 2.3 G and the proton luminosity (L$_{p}$) $1.56 \times 10^{46}$ erg/sec, whereas the lepton luminosity (L$_e$) $3.9 \times 10^{43}$ erg/sec.

Aims. To describe two potential options for the Source Environment Analysis pipeline, SEAPipe, for the Gaia mission. This pipeline will enable the discovery of sources which are new to Gaia, in the sense that they were not found by the on-board detection algorithm. These additional sources (secondaries) are discoverable in the vicinity of those Gaia sources (primaries) that were found by the on-board detection. Methods. The main algorithmic steps required are described; the 2-dimensional image reconstruction of 1-dimensional transit data, the analysis of these images to find the additional sources present, and the determination of the mean positions, proper motions, parallaxes and brightness of these sources. Additionally, the Monte Carlo simulations used to characterise the performance of the pipelines are described. Results. The performance of the two options for SEAPipe, the vanilla and image-subtraction versions, are compared. Their selection functions are computed in terms of the magnitude of the secondary sources and their angular separations from their corresponding primary source. The completeness and purity of the resultant catalogue of secondary sources as found by each of the pipelines, given the expected magnitude distribution of the primary sources and the magnitude and angular separation distributions of the secondary sources, is also presented. The image-subtraction pipeline is shown to out-perform the vanilla pipeline.

We have identified a broad absorption line (BAL) outflow in the HST/STIS spectrum of the quasar QSO B0254-3327B at velocity $v=-3200\text{ km s$^{-1}$}$. The outflow has absorption troughs from ions such as Ne VIII, Na IX, Si XII, and Ne V. We also report the first detection of S XIV absorption troughs, implying very high ionization. Via measurement of the ionic column densities, photoionization analysis, and determination of the electron number density of the outflow, we found the kinetic luminosity of the outflow system to be up to $\sim1\%$ of the quasar's Eddington luminosity, or $\sim2\%$ of the bolometric luminosity, making it a potential contributor to AGN feedback. A solution with two ionization phases was needed, as a single phase was not sufficient to satisfy the constraints from the measured ionic column densities. We find that the ionization parameter of the very high-ionization phase of the outflow is within the expected range of an X-ray warm absorber as described by arXiv:astro-ph/0309096. We also examined the physical properties of the outflow of Q0254-334 along with previously studied extreme UV outflows, with a total sample of 24 outflow systems, finding a weak negative correlation between outflow velocity and distance from the central source. The very high-ionization phase of the Q0254-334 outflow has one of the highest ionization parameters of UV absorption outflows to date, which we attribute to the presence of S XIV.

Planet formation models suggest that the small exoplanets that migrate from beyond the snowline of the protoplanetary disk likely contain water-ice-rich cores ($\sim 50\%$ by mass), also known as the water worlds. While the observed radius valley of the Kepler planets is well explained with the atmospheric dichotomy of the rocky planets, precise measurements of mass and radius of the transiting planets hint at the existence of these water worlds. However, observations cannot confirm the core compositions of those planets owing to the degeneracy between the density of a bare water-ice-rich planet and the bulk density of a rocky planet with a thin atmosphere. We combine different formation models from the Genesis library with atmospheric escape models, such as photo-evaporation and impact stripping, to simulate planetary systems consistent with the observed radius valley. We then explore the possibility of water worlds being present in the currently observed sample by comparing them with the simulated planets in the mass-radius-orbital period space. We find that the migration models suggest $\gtrsim 10\%$ and $\gtrsim 20\%$ of the bare planets, i.e. planets without primordial H/He atmospheres, to be water-ice-rich around G- and M-type host stars respectively, consistent with the mass-radius distributions of the observed planets. However, most of the water worlds are predicted to be outside a period of 10 days. A unique identification of water worlds through radial velocity and transmission spectroscopy is likely to be more successful when targeting such planets with longer orbital periods.

Formation of cosmological solitons is generically accompanied by production of gravitational waves (GWs), with a universal GW background expected at frequency scales below that of non-linear dynamics. Beginning with a general phenomenological description of GWs associated with soliton formation, we demonstrate that universal GW background from axion-like particle (ALP) solitonic oscillons provides a viable interpretation to the recent NANOGrav 15 year pulsar timing array data, which does not suffer from the overproduction of primordial black holes. We show that pulsar timing array data displays preference for models where formed solitons do not strongly interact or cluster. Coincidence observations with Nancy Roman telescope will allow to discriminate between distinct scenarios of cosmological solitons.

Classical Cepheids (DCEPs) play a fundamental role in the calibration of the extra-galactic distance ladder which eventually leads to the determination of the Hubble constant($H_0$) thanks to the period-luminosity ($PL$) and period-Wesenheit ($PW$) relations exhibited by these pulsating variables. Therefore, it is of great importance to establish the dependence of $PL/PW$ relations on metallicity. We aim at quantifying the metallicity dependence of the Galactic DCEPs' $PL/PW$ relations for a variety of photometric bands ranging from optical to near-infrared. We gathered a literature sample of 910 DCEPs with available [Fe/H] values from high-resolution spectroscopy or metallicities from \gaia\ Radial Velocity Spectrometer. For all these stars, we collected photometry in the $G_{BP},G_{RP},G,I,V,J,H,K_S$ bands and astrometry from the \gaia\ DR3. These data have been used to investigate the metal dependence of both intercepts and slopes of a variety of $PL/PW$ relations at multiple wavelengths. We find a large negative metallicity effect on the intercept ($\gamma$ coefficient) of all the $PL/PW$ relations investigated in this work, while present data still do not allow us to draw firm conclusions regarding the metal dependence of the slope ($\delta$ coefficient). The typical values of $\gamma$ are around $-0.4:-0.5$ mag/dex, i.e. larger than most of the recent determinations present in the literature. We carried out several tests which confirm the robustness of our results. As in our previous works, we find that the inclusion of global zero point offset of \gaia\ parallaxes provides smaller values of $\gamma$ (in an absolute sense). However, the assumption of the geometric distance of the LMC seems to indicate that larger values of $\gamma$ (in an absolute sense) would be preferred.

In this work, we investigated the interplay between the X-ray and radio emission of the cluster PSZ2G113.91-37.01 (z = 0.371) using the high-quality XMM-Newton observations of the CHEX-MATE project, and the images of the LoTSS-DR2. The cluster is undergoing a merger along the north-south axis, and shows a central radio halo and two radio relics, one in the southern and one in the northern regions. The analysis of the intracluster medium distribution revealed the presence of a northern surface brightness jump associated to the merger event. By extracting spectra across this discontinuity, we classified the edge as a cold front. Furthermore, we made use of upgraded Giant Metrewave Radio Telescope observations that allowed us to perform a spectral analysis of the G113 radio emission. We found evidence of re-acceleration of particles in the northern relic, and we measured an associated Mach number of M = 1.95 $\pm$ 0.01, as inferred from radio observations. We then performed a point-to-point analysis of the X-ray and radio emission both in the halo and in the northern relic regions. We found a strong correlation for the halo and an anti-correlation for the relic. The former behaviour is in agreement with previous studies. The relic anti-correlation is likely related to the reverse radial distribution of the X-ray (increasing towards the cluster centre) and radio (decreasing towards the cluster centre) emissions. Finally, we performed a point-to-point analysis of the radio emission and the residuals obtained by subtracting a double beta model to the X-ray emission. We found a strong correlation between the two quantities. This behaviour suggests the presence of a connection between the process responsible for the radio emission and the one that leaves fluctuations in the X-ray observations.

We analyse Gaia EDR3 parallax systematics as a function of magnitude and sky location using a recently published catalogue of 12,500 asteroseismic red-giant star distances. We selected ~ 3500 red clump (RC) stars of similar chemical composition as the optimal subsample for this purpose. We perform a detailed assessment of systematic uncertainties relevant for parallax offset estimation based on the asteroseismic distances. Following this assessment, we adopt for our baseline analysis the asteroseismic parameters measured as in Elsworth et al. (2020), spectroscopy from APOGEE (DR17), and we further restrict the sample to low-extinction RC stars with quality astrometric solutions from Gaia EDR3. We then investigated both the parallax offset relative to the published Gaia EDR3 parallaxes and the residual parallax offset after correcting Gaia EDR3 parallaxes following Lindegren et al. (2021). We find residual parallax offsets very close to zero (-1.6 +/- 0.5 (stat.) +/- 10 (syst.) muas) for stars fainter than G > 11 mag in the initial Kepler field. For 17 K2 campaigns in the same magnitude range, the residual parallax offset is +16.5 +/- 1.7 (stat.) +/- 10 (syst.) muas. At brighter magnitudes (G <= 11 mag), we find inconsistent residual parallax offsets between the Kepler field, 17 K2 campaigns, and the TESS southern continuous viewing zone, with differences of up to 60 muas. This suggests a significant dependence on sky location at bright magnitudes due to the lack of bright physical pairs available for determining the parallax offset corrections. Finally, we estimate the absolute magnitude of the RC and obtain M_Ks^RC = -1.650 +/- 0.025 mag in the 2MASS Ks-band and M_G^RC = (0.432 +/- 0.004) - (0.821 +/- 0.033) (Teff [K] - 4800K)/1000K [mag] in the Gaia G-band.

We present a detailed study of the observational biases of the DECam Ecliptic Exploration Project's (DEEP) B1 data release and survey simulation software that enables direct statistical comparisons between models and our data. We inject a synthetic population of objects into the images, and then subsequently recover them in the same processing as our real detections. This enables us to characterize the survey's completeness as a function of apparent magnitudes and on-sky rates of motion. We study the statistically optimal functional form for the magnitude, and develop a methodology that can estimate the magnitude and rate efficiencies for all survey's pointing groups simultaneously. We have determined that our peak completeness is on average 80\% in each pointing group, and our magnitude drops to $25\%$ of this value at $m_{25} = 26.22$. We describe the freely available survey simulation software and its methodology. We conclude by using it to infer that our effective search area for objects at 40 au is $14.8\deg^2$, and that our lack of dynamically cold distant objects means that there at most $8\times 10^3$ objects with $60 < a < 80$ au and absolute magnitudes $H \leq 8$.

We present the first set of trans-Neptunian objects (TNOs) observed on multiple nights in data taken from the DECam Ecliptic Exploration Project (DEEP). Of these 110 TNOs, 105 do not coincide with previously known TNOs and appear to be new discoveries. Each individual detection for our objects resulted from a digital tracking search at TNO rates of motion, using two to four hour exposure sets, and the detections were subsequently linked across multiple observing seasons. This procedure allows us to find objects with magnitudes $m_{VR} \approx 26$. The object discovery processing also included a comprehensive population of objects injected into the images, with a recovery and linking rate of at least $94\%$. The final orbits were obtained using a specialized orbit fitting procedure that accounts for the positional errors derived from the digital tracking procedure. Our results include robust orbits and magnitudes for classical TNOs with absolute magnitudes $H \sim 10$, as well as a dynamically detached object found at 76 au (semi-major axis $a\approx 77 \, \mathrm{au}$). We find a disagreement between our population of classical TNOs and the CFEPS-L7 three component model for the Kuiper belt.

Recent observations are shedding light on the important role that active galactic nuclei (AGN) play in the production of high-energy neutrinos. In this study, we focus on one object, 5BZB J0630-2406, which is among the blazars recently proposed as associated with neutrino emission during the first 7-yr IceCube observations. Modelling the quasi-simultaneous, broad-band spectral energy distribution, we explore various scenarios from purely leptonic to lepto-hadronic models, testing the inclusion of external photon fields. This theoretical study provides a complementary testing ground for the proposed neutrino-blazar association. Despite being historically classified as a BL Lac, our study shows that 5BZB J0630-2406 belongs to the relatively rare sub-class of high-power flat-spectrum radio quasars (FSRQs). Our results indicate that interactions between protons and external radiation fields can produce a neutrino flux that is within the reach of the IceCube detector. Furthermore, the spectral shape of the X-ray emission suggests the imprint of hadronic processes related to very energetic protons.

A key goal of exoplanet spectroscopy is to measure atmospheric properties, such as abundances of chemical species, in order to connect them to our understanding of atmospheric physics and planet formation. In this new era of high-quality JWST data, it is paramount that these measurement methods are robust. When comparing atmospheric models to observations, multiple candidate models may produce reasonable fits to the data. Typically, conclusions are reached by selecting the best-performing model according to some metric. This ignores model uncertainty in favour of specific model assumptions, potentially leading to measured atmospheric properties that are overconfident and/or incorrect. In this paper, we compare three ensemble methods for addressing model uncertainty by combining posterior distributions from multiple analyses: Bayesian model averaging, a variant of Bayesian model averaging using leave-one-out predictive densities, and stacking of predictive distributions. We demonstrate these methods by fitting the HST+Spitzer transmission spectrum of the hot Jupiter HD 209458b using models with different cloud and haze prescriptions. All of our ensemble methods lead to uncertainties on retrieved parameters that are larger, but more realistic, and consistent with physical and chemical expectations. Since they have not typically accounted for model uncertainty, uncertainties of retrieved parameters from HST spectra have likely been underreported. We recommend stacking as the most robust model combination method. Our methods can be used to combine results from independent retrieval codes, and from different models within one code. They are also widely applicable to other exoplanet analysis processes, such as combining results from different data reductions.

Recent observations and simulations reveal that the circumgalactic medium (CGM) surrounding galaxies is multiphase, with the gas temperatures spanning a wide range at most radii -- $\sim 10^4 {\rm~K}$ to the virial temperature ($\sim 10^6$ K for Milky Way). Traditional CGM models using simple density profiles are inadequate in describing such a multiphase atmosphere. Alternatively, a model based on probability distribution functions (PDFs) with parameters motivated by relevant physical processes can better match multi-wavelength observations. In this work, we use log-normal distributions, commonly seen in the simulations of the multiphase interstellar and circumgalactic media, to quantify the volume fraction of different phases. We generalize the isothermal background model by Faerman et al. 2017 to include more general CGM profiles. We extend the existing probabilistic models from 1D-PDFs in temperature to 2D-PDFs in density-temperature phase space and constrain its parameters using a Milky Way-like {\tt Illustris TNG50-1} halo. We generate various synthetic observables such as column densities of different ions, UV/X-ray spectra, dispersion, and emission measures. X-ray and radio (Fast Radio Burst) observations constrain the hot gas properties. However, interpreting cold/warm phase diagnostics is not straightforward since these phases are clumpy/patchy, with inherent variability in intercepting these clouds along arbitrary lines of sight. We provide a tabulated comparison of model predictions to observations, and plan to expand this into a comprehensive compilation of models and data. Our modeling provides a simple, analytic framework that is useful to describe important aspects of the multiphase CGM.

Eclipse mapping is a technique for inferring 2D brightness maps of transiting exoplanets from the shape of an eclipse light curve. With JWST's unmatched precision, eclipse mapping is now possible for a large number of exoplanets. However, eclipse mapping has only been applied to two planets and the nuances of fitting eclipse maps are not yet fully understood. Here, we use Leave-one-out Cross- Validation (LOO-CV) to investigate eclipse mapping, with application to a JWST NIRISS/SOSS observation of the ultra-hot Jupiter WASP-18b. LOO-CV is a technique that provides insight into the out-of-sample predictive power of models on a data-point-by-data-point basis. We show that constraints on planetary brightness patterns behave as expected, with large-scale variations driven by the phase-curve variation in the light curve and smaller-scale structures constrained by the eclipse ingress and egress. For WASP-18b we show that the need for higher model complexity (smaller-scale features) is driven exclusively by the shape of the eclipse ingress and egress. We use LOO-CV to investigate the relationship between planetary brightness map components when mapping under a positive-flux constraint to better understand the need for complex models. Finally, we use LOO-CV to understand the degeneracy between the competing ``hotspot'' and ``plateau'' brightness map models of WASP-18b, showing that the plateau model is driven by the ingress shape and the hotspot model is driven by the egress shape, but preference for neither model is due to outliers or unmodeled signals. Based on this analysis, we make recommendations for the use of LOO-CV in future eclipse-mapping studies.

Cosmological inferences typically rely on explicit expressions for the likelihood and covariance of the data vector, which normally consists of a set of summary statistics. However, in the case of nonlinear large-scale structure, exact expressions for either likelihood or covariance are unknown, and even approximate expressions can become very cumbersome, depending on the scales and summary statistics considered. Simulation-based inference (SBI), in contrast, does not require an explicit form for the likelihood but only a prior and a simulator, thereby naturally circumventing these issues. In this paper, we explore how this technique can be used to infer $\sigma_8$ from a Lagrangian effective field theory (EFT) based forward model for biased tracers. The power spectrum and bispectrum are used as summary statistics to obtain the posterior of the cosmological, bias and noise parameters via neural density estimation. We compare full simulation-based inference with cases where the data vector is drawn from a Gaussian likelihood with sample and analytical covariances. We conclude that, for $k_{\text{max}}=0.1h\text{Mpc}^{-1}$ and $0.2h\text{Mpc}^{-1}$, the form of the covariance is more important than the non-Gaussianity of the likelihood, although this conclusion is expected to depend on the cosmological parameter inferred, the summary statistics considered and range of scales probed.

Vorticity has recently been suggested to be a property of highly-spinning black holes. The connection between vorticity and limiting spin represents a universal feature shared by objects of maximal microstate entropy, so-called saturons. Using $Q$-ball-like saturons as a laboratory for black holes, we study the collision of two such objects and find that vorticity can have a large impact on the emitted radiation as well as on the charge and angular momentum of the final configuration. As black holes belong to the class of saturons, we expect that the formation of vortices can cause similar effects in black hole mergers, leading to macroscopic deviations in gravitational radiation. This could leave unique signatures detectable with upcoming gravitational-wave searches, which can thereby serve as a portal to macroscopic quantum effects in black holes.

The reach of sub-GeV dark-matter detectors is at present severely affected by low-energy events from various origins. We present the theoretical methods to compute the single- and few-electron events that arise from secondary radiation emitted by high-energy particles passing through detector materials and perform simulations to quantify them at (Skipper) CCD-based experiments, focusing on the SENSEI data collected in the MINOS cavern at Fermilab. The simulations account for the generation of secondaries from Cherenkov and luminescent recombination; photo-absorption, reflection, refraction and thin-film interference in detector materials; roughness of the interfaces and the dynamics of charges and partial charge collection (PCC) in the doped CCD-backside. We consider several systematic uncertainties, notably those stemming from the backside charge-diffusion modeling, which we estimate with a "fiducial'' and an "extreme'' model, with the former model presenting better agreement with PCC data. We find that Cherenkov photons constitute about 40% of the observed single-electron events for both models; radiative recombination rates are negligible for the fiducial model, but can dominate over the Cherenkov rates for the extreme model. We also estimate the fraction of 2-electron events from 1-electron event same-pixel coincidences, finding that the entire 2-electron rate can be explained by coincidences of radiative events and spurious charge. Accounting for backgrounds, we project the sensitivity of future Skipper-CCD-based experiments to different dark-matter models. For light-mediator models with dark-matter masses of 1, 5, and 10 MeV, we find that future experiments with 10-kg-year exposures and successful background mitigation could have a sensitivity that is larger by 9, 3, and 2 orders of magnitude, respectively, when compared to an experiment without background improvements. (abridged)

We consider a model where the interaction between dark matter and the Standard Model particles are mediated by a ghost-free bi-gravity portal. The bi-gravity model invokes a massive spin-2 particle coupled to the usual massless graviton as well as generic bi-metric matter couplings. The cross-sections for dark matter direct detection are computed and confronted with the experimental bounds. The presence of the massive spin-2 mediator resolves the core-cusp problem, which in turn significantly constrains the dark matter coupling in such a bi-gravity theory. Yet, there remains a window of the parameter space where the model can be tested in the upcoming direct detection experiments such as XENONnT and PandaX-30T. The model also predicts a reheating temperature of the order of $10^6$ GeV.

We consider non-local modifications of General Relativity given by a distortion function in terms of the inverse of the d'Alembert operator. The inclusion of these terms is motivated by the possibility of reproducing the current accelerated expansion of the Universe starting from non-local gravity. In particular, we propose a model-independent method, based on current observations, to reconstruct the shape of the distortion function, without resorting to a specific cosmological history. We describe a numerical procedure based on Pad\'e polynomials that allows us to study the time evolution of the auxiliary scalar fields introduced to localize non-local gravity action. Thus, adopting suitable boundary conditions, we reconstruct the form of the non-local Lagrangian and infer the best analytical approximation of the numerical outcome. Furthermore, the distortion function turns on during the matter-dominated era, and its effects are delayed to the most recent cosmic times. This provides a natural explanation for the late cosmic acceleration, avoiding any fine-tuning problem of the cosmological constant. Finally, we compare our predictions with previous findings based on enforcing the standard $\Lambda$CDM background in the reconstruction process.

The Earth's magnetic field is generated by a dynamo in the outer core and is crucial for shielding our planet from harmful radiation. Despite the established importance of the core-mantle boundary heat flux as driver for the dynamo, open questions remain about how heat flux heterogeneities affect the magnetic field. Here, we explore the distribution of core-mantle boundary heat flux on Earth and its changes over time using compressible global 3-D mantle convection models in the geodynamic modeling software ASPECT. We discuss the use of the consistent boundary flux method as a tool to more accurately compute boundary heat fluxes in finite element simulations and the workflow to provide the computed heat flux patterns as boundary conditions in geodynamo simulations. Our models use a plate reconstruction throughout the last 1 billion years -- encompassing the complete supercontinent cycle -- to determine the location and sinking speed of subducted plates. The results show how mantle upwellings and downwellings create localized heat flux anomalies at the core-mantle boundary that can vary drastically over Earth's history and depend on the properties and evolution of the lowermost mantle as well as the surface subduction zone configuration. The distribution of hot and cold structures at the core-mantle boundary changes throughout the supercontinent cycle in terms of location, shape and number, indicating that these structures fluctuate and might have looked very differently in Earth's past. Our results have implications for understanding the Earth's thermal evolution and the stability of its magnetic field over geological timescales. They provide insights into the potential effects of the mantle on the magnetic field and pave the way for further exploring questions about the nucleation of the inner core and the past state of the lowermost mantle.

Space-based gravitational wave detectors like TianQin or LISA could observe extreme-mass-ratio-inspirals (EMRIs) at millihertz frequencies. The accurate identification of these EMRI signals from the data plays a crucial role in enabling in-depth study of astronomy and physics. We aim at the identification stage of the data analysis, with the aim to extract key features of the signal from the data, such as the evolution of the orbital frequency, as well as to pinpoint the parameter range that can fit the data well for the subsequent parameter inference stage. In this manuscript, we demonstrated the identification of EMRI signals without any additional prior information on physical parameters. High-precision measurements of EMRI signals have been achieved, using a hierarchical search. It combines the search for physical parameters that guide the subsequent parameter inference, and a semi-coherent search with phenomenological waveforms that reaches precision levels down to $10^{-4}$ for the phenomenological waveform parameters $\omega_{0}$, $\dot{\omega}_{0}$, and $\ddot{\omega}_{0}$. As a result, we obtain measurement relative errors of less than 4% for the mass of the massive black hole, while keeping the relative errors of the other parameters within as small as 0.5%.

We study the possibility of generating light Dirac neutrino mass via scotogenic mechanism where singlet-doublet fermion dark matter (DM) plays non-trivial role in generating one-loop neutrino mass, anomalous magnetic moment of muon $(g-2)_\mu$ as well as additional relativistic degrees of freedom $\Delta{N_{\rm eff}}$ within reach of cosmic microwave background (CMB) experiments. We show that the Dirac nature of neutrinos can bring interesting correlations within the parameter space satisfying the $\left(g-2\right)_\mu$ anomaly and DM relic density and the effective relativistic degrees of freedom $\Delta{N_{\rm eff}}$. While we stick to thermal singlet doublet DM with promising detection prospects, both thermal and non-thermal origin of $\Delta{N_{\rm eff}}$ have been explored. In addition to detection prospects at DM, $(g-2)$ and other particle physics experiments, the model remains verifiable at future CMB experiments like CMB-S4, SPT-3G.