Papers for Monday, Nov 07 2022

Cosmological perturbation theory is known to converge poorly for predicting the spherical collapse and void evolution of collisionless matter. Using the exact parametric solution as a testing ground, we develop two asymptotic methods in spherical symmetry that resolve the gravitational evolution to much higher accuracy than Lagrangian perturbation theory (LPT), which is the current gold standard in the literature. One of the methods selects a stable fixed-point solution of the renormalization-group flow equation, thereby predicting already at the leading order the critical exponent of the phase transition of collapsing structures. The other method completes the truncated LPT series far into the ultra-violet (UV) regime, by adding a non-analytic term that captures the critical nature of the gravitational collapse. We find that the UV method most accurately resolves the evolution of the non-linear density as well as its one-point probability distribution function. Similarly accurate predictions are achieved with the renormalization-group method, especially when paired with Pad\'e approximants. Further, our results yield new, very accurate, formulae to relate linear and non-linear density contrasts. Finally, we chart possible ways on how to adapt our methods to the case of cosmological random field initial conditions.

The UltraViolet imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey Fields (UVCANDELS) program provides HST/UVIS F275W imaging for four CANDELS fields. We combine this UV imaging with existing HST/near-IR grism spectroscopy from 3D-HST+AGHAST to directly compare the resolved rest-frame UV and H$\alpha$ emission for a sample of 979 galaxies at $0.7<z<1.5$ spanning a range in stellar mass of $10^{8-11.5}~M_\odot$. Since both rest-UV and H$\alpha$ are sensitive to on-going star-formation but over different timescales, their resolved comparison allows us to infer the burstiness in star-formation as a function of galaxy structural parameters. We generate homogenized maps of rest-UV and H$\alpha$ emission for all galaxies in our sample and stack them to compute the average UV-to-H$\alpha$ luminosity ratio as a function of galactocentric radius. We find that galaxies below stellar mass of $\sim10^{9.5}~M_\odot$, at all radii, have a UV-to-H$\alpha$ ratio higher than the equilibrium value expected from constant star-formation, indicating a significant contribution from bursty star-formation. Even for galaxies with stellar mass $\gtrsim10^{9.5} M_\odot$, the UV-to-H$\alpha$ ratio is elevated towards in their outskirts ($R/R_{eff}>1.5$), suggesting that bursty star-formation is likely prevalent in the outskirts of even the most massive galaxies but is likely over-shadowed by their brighter cores. Furthermore, we present the UV-to-H$\alpha$ ratio as a function of galaxy surface brightness, a proxy for stellar mass surface density, and find that regions below $\sim10^8~M_\odot~kpc^{-2}$ are consistent with bursty star-formation, regardless of their galaxy stellar mass, potentially suggesting that local star-formation is independent of global galaxy properties at the smallest scales.

In August of 2021, Fermi-LAT, H.E.S.S., and MAGIC detected GeV and TeV $\gamma$-ray emission from an outburst of recurrent nova RS Ophiuchi. This detection represents the first very high energy $\gamma$-rays observed from a nova, and opens a new window to study particle acceleration. Both H.E.S.S. and MAGIC described the observed $\gamma$-rays as arising from a single, external shock. In this paper, we perform detailed, multi-zone modeling of RS Ophiuchi's 2021 outburst including a self-consistent prescription for particle acceleration and magnetic field amplification. We demonstrate that, contrary to previous work, a single shock cannot simultaneously explain RS Ophiuchi's GeV and TeV emission, particularly the spectral shape and distinct light curve peaks. Instead, we put forward a model involving multiple shocks that reproduces the observed $\gamma$-ray spectrum and temporal evolution. The simultaneous appearance of multiple distinct velocity components in the nova optical spectrum over the first several days of the outburst supports the presence of distinct shocks, which may arise either from the strong latitudinal dependence of the density of the external circumbinary medium (e.g., in the binary equatorial plane versus the poles) or due to internal collisions within the white dwarf ejecta (as powers the $\gamma$-ray emission in classical novae).

Recent studies have demonstrated that the emission from the circumgalactic medium of the Milky Way displays a relatively high degree of patchiness on angular scales of $\sim10^\circ$. Taking advantage of the Spectrum Roentgen Gamma eROSITA Final Equatorial Depth Survey (eFEDS), we aim to constrain any variation in the soft X-ray surface brightness on scales going from sub-degree to a hundred square degrees. We observe modulations of about $60$% on scales of several degrees and decreasing for higher energies. The observed patchiness is stable over a period of two years, therefore excluding that it is induced by Solar wind charge exchange. We also observe no correlation between such excess and the density of galaxies in the Local Universe, suggesting no strong contribution from the hot baryons in the filaments of the Cosmic web. Instead, the soft X-ray emission is anti-correlated with the column density of absorbing material. Indeed, we can reproduce the spectrum of the bright and dark regions by simply varying the column density of the matter absorbing the emission components located beyond the Local Hot Bubble, while no modulation of the intrinsic emission is required. At high Galactic latitudes, the eROSITA all sky map shows patchiness of the soft X-ray diffuse emission similar to the one observed in the eFEDS field, it is therefore likely that the same "absorption-modulation" is present over the entire sky. These results highlight the importance of an accurate treatment of the absorption effects, to determine the patchiness of the circumgalactic medium.

The period-luminosity relations (PLR) of Milky Way $\delta$ Scuti ($\delta$ Sct) stars have been described to the present day by a linear relation. However, when studying extragalactic systems such as the Magellanic Clouds and several dwarf galaxies, we notice for the first time a non-linear behaviour in the PLR of $\delta$ Sct stars. Using the largest sample of $\sim 3700$ extragalactic $\delta$ Sct stars from data available in the literature $-$mainly based on OGLE and SuperMACHO survey in the Large Magellanic Cloud (LMC)$-$ we obtain that the best fit to the period-luminosity ($M_V$) plane is given by the following piecewise linear relation with a break at $\log{P} = -1.03 \pm 0.01$ (or $0.093 \pm 0.002$ d) for shorter periods (sp) and longer periods (lp) than the break-point: $$M_V^{sp} = -7.08 (\pm 0.25) \log{P} -5.74 (\pm 0.29) ;\hspace{5pt} \log{P} < -1.03$$ $$M_V^{lp} = M_V^{sp} + 4.38 (\pm 0.32) \cdot (\log{P} + 1.03 (\pm 0.01));\hspace{5pt} \log{P} \geq -1.03$$ Geometric or depth effects in the LMC, metallicity dependence, or different pulsation modes are discarded as possible causes of this segmented PLR seen in extragalactic $\delta$ Sct stars. The origin of the segmented relation at $\sim 0.09$ days remains unexplained based on the current data.

We report the discovery of a unique object in the MeerKAT Galaxy Cluster Legacy Survey (MGCLS) using a machine learning anomaly detection algorithm. This strange, ring-like source is 30' from the MGCLS field centred on Abell 209, and is not readily explained by simple physical models. With an assumed host galaxy at redshift 0.55, the luminosity (10^25 W/Hz) is comparable to powerful radio galaxies. The source consists of a ring of emission 175 kpc across, quadrilateral enhanced brightness regions bearing resemblance to radio jets, two ``ears'' separated by 368 kpc, and a diffuse envelope. All of the structures appear spectrally steep, ranging from -1.0 to -1.5. The ring has high polarization (25%) except on the bright patches (<10%). We compare this source to the Odd Radio Circles recently discovered in ASKAP data and discuss several possible physical models, including a termination shock from starburst activity, an end-on radio galaxy, and a supermassive black hole merger event. No simple model can easily explain the observed structure of the source. This work, as well as other recent discoveries, demonstrates the power of unsupervised machine learning in mining large datasets for scientifically interesting sources.

We compare 500~pc scale, resolved observations of ionised and molecular gas for the $z\sim0.02$ starbursting disk galaxy IRAS08339+6517, using measurements from KCWI and NOEMA. We explore the relationship of the star formation driven ionised gas outflows with colocated galaxy properties. We find a roughly linear relationship between the outflow mass flux ($\dot{\Sigma}_{\rm out}$) and star formation rate surface density ($\Sigma_{\rm SFR}$), $\dot{\Sigma}_{\rm out}\propto\Sigma_{\rm SFR}^{1.06\pm0.10}$, and a strong correlation between $\dot{\Sigma}_{\rm out}$ and the gas depletion time, such that $\dot{\Sigma}_{\rm out} \propto t_{dep}^{-1.1\pm0.06}$. Moreover, we find these outflows are so-called ``breakout" outflows, according to the relationship between the gas fraction and disk kinematics. Assuming that ionised outflow mass scales with total outflow mass, our observations suggest that the regions of highest $\Sigma_{\rm SFR}$ in IRAS08 are removing more gas via the outflow than through the conversion of gas into stars. Our results are consistent with a picture in which the outflow limits the ability for a region of a disk to maintain short depletion times. Our results underline the need for resolved observations of outflows in more galaxies.

A supersonic relative velocity between dark matter (DM) and baryons (the stream velocity) at the time of recombination induces the formation of low mass objects with anomalous properties in the early Universe. We widen the scope of the `Supersonic Project' paper series to include objects we term Dark Matter + Gas Halos Offset by Streaming (DM GHOSts)--diffuse, DM-enriched structures formed because of a physical offset between the centers of mass of DM and baryonic overdensities. We present an updated numerical investigation of DM GHOSts and Supersonically Induced Gas Objects (SIGOs), including the effects of molecular cooling, in high resolution hydrodynamic simulations using the AREPO code. Supplemented by an analytical understanding of their ellipsoidal gravitational potentials, we study the population-level properties of these objects, characterizing their morphology, spin, radial mass, and velocity distributions in comparison to classical structures in non-streaming regions. The stream velocity causes deviations from sphericity in both the gas and DM components and lends greater rotational support to the gas. Low mass ($<\sim 10^{5.5}$ M$_\odot$) objects in regions of streaming demonstrate core-like rotation and mass profiles. Anomalies in the rotation and morphology of DM GHOSts could represent an early Universe analogue to observed ultra-faint dwarf galaxies with variations in DM content and unusual rotation curves.

Novel summary statistics beyond the standard 2-point correlation function (2PCF) are necessary to capture the full astrophysical and cosmological information from the small-scale ($r < 30h^{-1}$Mpc) galaxy clustering. However, the analysis of beyond-2PCF statistics on small scales is challenging because we lack the appropriate treatment of observational systematics for arbitrary summary statistics of the galaxy field. In this paper, we develop a full forward modeling pipeline for any summary statistics using high-fidelity simulation lightcones that accounts for all observational systematics and is appropriate for a wide range of summary statistics. We apply our forward model approach to a fully realistic mock galaxy catalog and demonstrate that we can recover unbiased constraints on the underlying galaxy--halo connection model using two separate summary statistics: the standard 2PCF and the novel $k$-th nearest neighbor ($k$NN) statistics, which are sensitive to correlation functions of all orders. We expect that applying this forward model approach to current and upcoming surveys while leveraging a multitude of summary statistics will become a powerful technique in maximally extracting information from the non-linear scales.

Due to their extremely dust-obscured nature, much uncertainty still exists surrounding the stellar mass growth and content in dusty, star-forming galaxies (DSFGs) at $z>1$. In this work, we present a numerical model built using empirical data on DSFGs to estimate their stellar mass contributions across the first $\sim$10 Gyr of cosmic time. We generate a dust-obscured stellar mass function that extends beyond the mass limit of star-forming stellar mass functions in the literature, and predict that massive DSFGs constitute as much as $50-100\%$ of all star-forming galaxies with M $\ge10^{11}$M$_\odot$ at $z>1$. We predict the number density of massive DSFGs and find general agreement with observations, although more data is needed to narrow wide observational uncertainties. We forward model mock massive DSFGs to their quiescent descendants and find remarkable agreement with observations from the literature demonstrating that, to first order, massive DSFGs are a sufficient ancestral population to describe the prevalence of massive quiescent galaxies at $z>1$. We predict that massive DSFGs and their descendants contribute as much as $25-60\%$ to the cosmic stellar mass density during the peak of cosmic star formation, and predict an intense epoch of population growth during the $\sim1$ Gyr from $z=6$ to 3 during which the majority of the most massive galaxies at high-$z$ grow and then quench. Future studies seeking to understand massive galaxy growth and evolution in the early Universe should strategize synergies with data from the latest observatories (e.g. JWST and ALMA) to better include the heavily dust-obscured galaxy population.

Blazars are a rare class of active galactic nuclei (AGN) with relativistic jets pointing towards the observer. Jets are thought to be launched as Poynting-flux dominated outflows that accelerate to relativistic speeds at the expense of the available magnetic energy. In this work, we consider electron-proton jets and assume that particles are energized via magnetic reconnection in parts of the jet where the magnetization is still high ($\sigma \ge 1$). The magnetization and bulk Lorentz factor $\Gamma$ are related to the available jet energy per baryon as $\mu =\Gamma(1+\sigma)$. We adopt an observationally motivated relation between $\Gamma$ and the mass accretion rate into the black hole $\dot{m}$, which also controls the luminosity of external radiation fields. We numerically compute the photon and neutrino jet emission as a function of $\mu$ and $\sigma$. We find that the blazar SED is produced by synchrotron and inverse Compton radiation of accelerated electrons, while the emission of hadronic-related processes is subdominant except for the highest magnetization considered. We show that low-luminosity blazars ($L_{\gamma} \lesssim 10^{45}$ erg s$^{-1}$) are associated with less powerful, slower jets with higher magnetizations in the jet dissipation region. Their broadband photon spectra resemble those of BL Lac objects, and the expected neutrino luminosity is $L_{\nu+\bar{\nu}}\sim (0.3-1)\, L_{\gamma}$. High-luminosity blazars ($L_{\gamma} \gg 10^{45}$ erg s$^{-1}$) are associated with more powerful, faster jets with lower magnetizations. Their broadband photon spectra resemble those of flat spectrum radio quasars, and they are expected to be dim neutrino sources with $L_{\nu+\bar{\nu}}\ll L_{\gamma}$.

We present a new selection of 358 blue compact dwarf galaxies (BCDs) from 5,000 square degrees in the Dark Energy Survey (DES), and the spectroscopic follow-up of a subsample of 68 objects. For the subsample of 34 objects with deep spectra, we measure the metallicity via the direct T$_e$ method using the auroral [\oiii]$\lambda$ 4363 emission line. These BCDs have average oxygen abundance of 12+log(O/H)= 7.8, stellar masses between 10$^7$ to 10$^8$ M$_\odot$ and specific SFR between $\sim$ 10$^{-9}$ to 10$^{-7}$ yr$^{-1}$. We compare the position of our BCDs with the Mass-metallicity (M-Z) and Luminosity-metallicity (L-Z) relation derived from the Local Volume Legacy sample. We find the scatter around the M-Z relation is smaller than the scatter around the L-Z relation. We identify a correlation between the offsets from the M-Z and L-Z relation that we suggest is due to the contribution of metal-poor inflows. Finally, we explore the validity of the mass-metallicity-SFR fundamental plane in the mass range probed by our galaxies. We find that BCDs with stellar masses smaller than $10^{8}$M$_{\odot}$ do not follow the extrapolation of the fundamental plane. This result suggests that mechanisms other than the balance between inflows and outflows may be at play in regulating the position of low mass galaxies in the M-Z-SFR space.

Accreting protoplanets represent a window into planet formation processes. We report H{\alpha} differential imaging results from the deepest and most comprehensive accreting protoplanet survey to date, acquired with the Magellan Adaptive Optics (MagAO) system's VisAO camera. The fourteen transitional disks targeted are ideal candidates for protoplanet discovery due to their wide, heavily depleted central cavities, wealth of non-axisymmetric circumstellar disk features evocative of ongoing planet formation, and ongoing stellar accretion. To address the twin challenges of morphological complexity in the target systems and PSF instability, we develop novel approaches for frame selection and optimization of the Karhounen-Loeve Image Processing algorithm pyKLIP. We detect one new candidate protoplanet, CS Cha "c", at a separation of 75mas and a {\Delta}mag of 5.1 and robustly recover the HD142527 B and HD100453 B low mass stellar companions across multiple epochs. Though we cannot rule out a substantial scattered light contribution to its emission, we also recover LkCa 15 b. Its presence inside of the cleared disk cavity and consistency with a forward-modeled point source suggest that it remains a viable protoplanet candidate. The protoplanet PDS 70 c was marginally recovered under our conservative general methodology. However, through targeted optimization in H{\alpha} imagery, we tentatively recover PDS 70 c in three epochs and PDS 70 b in one epoch. Of the many other previously-reported companions and companion candidates around objects in the sample, we do not recover any additional robust candidates. However, lack of recovery at moderate H{\alpha} contrast does not rule out the presence of protoplanets at these locations, and we report limiting H{\alpha} contrasts in such cases.

In this paper, we review some of the extant literature on the study of interstellar objects (ISOs). With the forthcoming Vera C. Rubin Telescope and Legacy Survey of Space and Time (LSST), we find that $0.38 - 84$ `Oumuamua-like interstellar objects are expected to be detected in the next 10 years, with 95\% confidence. The feasibility of a rendezvous trajectory has been demonstrated in previous work. In this paper, we investigate the requirements for a rendezvous mission with the primary objective of producing a resolved image of an interstellar object. We outline the rendezvous distances necessary as a function of resolution elements and object size. We expand upon current population synthesis models to account for the size dependency on the detection rates for reachable interstellar objects. We assess the trade-off between object diameter and occurrence rate, and conclude that objects with the size range between a third of the size and the size of `Oumuamua will be optimal targets for an imaging rendezvous. We also discuss expectations for surface properties and spectral features of interstellar objects, as well as the benefits of various spacecraft storage locations.

Orbital eccentricities directly trace the formation mechanisms and dynamical histories of substellar companions. Here, we study the effect of hyperpriors on the population-level eccentricity distributions inferred for the sample of directly imaged substellar companions (brown dwarfs and cold Jupiters) from hierarchical Bayesian modeling (HBM). We find that the choice of hyperprior can have a significant impact on the population-level eccentricity distribution inferred for imaged companions, an effect that becomes more important as the sample size and orbital coverage decrease to values that mirror the existing sample. We reanalyse the current observational sample of imaged giant planets in the 5-100 AU range from Bowler et al. (2020) and find that the underlying eccentricity distribution implied by the imaged planet sample is broadly consistent with the eccentricity distribution for close-in exoplanets detected using radial velocities. Furthermore, our analysis supports the conclusion from that study that long-period giant planets and brown dwarf eccentricity distributions differ by showing that it is robust to the choice of hyperprior. We release our HBM and forward modeling code in an open-source Python package, ePop!, and make it freely available to the community.

We construct observational Hubble $H(z)$ and angular diameter distance $D_{A}(z)$ mock data with baseline Planck $\Lambda$CDM input values, before fitting the $\Lambda$CDM model to study evolution of probability density functions (PDFs) of best fit cosmological parameters $(H_0, \Omega_m, \Omega_k)$ across redshift bins. We find that PDF peaks only agree with the input parameters in low redshift ($z \lesssim 1$) bins for $H(z)$ and $D_{A}(z)$ constraints, and in all redshift bins when $H(z)$ and $D_{A}(z)$ constraints are combined. When input parameters are not recovered, we observe that PDFs exhibit non-Gaussian tails towards larger $\Omega_m$ values and shifts to (less pronounced) peaks at smaller $\Omega_m$ values. This flattening of the PDF is expected as $H(z)$ and $D_{A}(z)$ observations only constrain combinations of cosmological parameters at higher redshifts, so uniform PDFs are expected. Our analysis leaves us with a choice to bin high redshift data in the knowledge that we may be unlikely to recover Planck values, or conduct full sample analysis that biases $\Lambda$CDM inferences to the lower redshift Universe.

Gaia19fct is one of the Gaia-alerted eruptive young stars that has undergone several brightening events. We conducted monitoring observations using multi-filter optical and near-infrared photometry, as well as near-infrared spectroscopy, to understand the physical properties of Gaia19fct and investigate whether it fits into the historically defined two classes. We present the analyses of light curves, color variations, spectral lines, and CO modeling. The light curves show at least five brightening events since 2015, and the multi-filter color evolutions are mostly gray. The gray evolution indicates that bursts are triggered by mechanisms other than extinction. Our near-infrared spectra exhibit both absorption and emission lines and show time-variability throughout our observations. We found lower rotational velocity and lower temperature from the near-infrared atomic absorption lines than from the optical lines, suggesting that Gaia19fct has a Keplerian rotating disk. The CO overtone features show a superposition of absorption and emission components, which is unlike other young stellar objects. We modeled the CO lines, and the result suggests that the emission and absorption components are formed in different regions. We found that although Gaia19fct exhibits characteristics of both types of eruptive young stars, FU Orionis-type objects (FUors) and EX Lupi-type objects (EXors), it shows more similarity with EXors in general.

Our understanding of magnetic reconnection (MR) under chromospheric conditions remains limited. Recent observations have demonstrated the important role of ion-neutral interactions in the dynamics of the chromosphere. Furthermore, the comparison between spectral profiles and synthetic observations of reconnection events suggest that current MHD approaches appear to be inconsistent with observations. First, collisions and multi-thermal aspects of the plasma play a role in these regions. Second, hydrogen and helium ionization effects are relevant to the energy balance of the chromosphere. This work investigates multi-fluid multi-species (MFMS) effects on MR in conditions representative of the upper chromosphere using the multi-fluid Ebysus code. We compare an MFMS approach based on a helium-hydrogen mixture with a two-fluid MHD model based on hydrogen only. The simulations of MRs are performed in a Lundquist number regime high enough to develop plasmoids and instabilities. We study the evolution of the MR and compare the two approaches including the structure of the current sheet and plasmoids, the decoupling of the particles, the evolution of the heating mechanisms, and the composition. The presence of helium species leads to more efficient heating mechanisms than the two-fluid case. This scenario, which is out of reach of the two-fluid or single-fluid models, can reach transition region temperatures starting from upper chromospheric thermodynamic conditions, representative of a quiet Sun scenario. The different dynamics between helium and hydrogen species could lead to chemical fractionation and, under certain conditions, enrichment of helium in the strongest outflows. This could be of significance for recent observations of helium enrichment in the solar wind in switchbacks and CMEs.

When a compact object is formed in a binary, any mass lost during core collapse will impart a kick on the binary's center of mass. Asymmetries in this mass loss would impart an additional natal kick on the remnant black hole or neutron star, whether it was formed in a binary or in isolation. While it is well established that neutron stars receive natal kicks upon formation, it is unclear whether black holes do as well. Here, we consider the low-mass X-ray binary MAXI J1305-704, which has been reported to have a space velocity $\gtrsim$ 200 km/s. In addition to integrating its trajectory to infer its velocity upon formation of its black hole, we reconstruct its evolutionary history, accounting for recent estimates of its period, black hole mass, mass ratio, and donor effective temperature from photometric and spectroscopic observations. We find that if MAXI J1305-704 formed via isolated binary evolution in the thick Galactic disk, then its black hole received a natal kick of at least 70 km/s with 95\% confidence.

We present an observational analysis of the electron thermal energy budget using data from Parker Solar Probe. We use the macroscopic moments, obtained from our fits to the measured electron distribution function, to evaluate the thermal energy budget based on the second moment of the Boltzmann equation. We separate contributions to the overall budget from reversible and irreversible processes. We find that a thermal-energy source must be present in the inner heliosphere over the heliocentric distance range from 0.15 to 0.47 au. The divergence of the heat flux is positive at heliocentric distances below 0.33 au, while beyond 0.33 au, there is a measurable degradation of the heat flux. Expansion effects dominate the thermal energy budget below 0.3 au. Under our steady-state assumption, the free streaming of the electrons is not sufficient to explain the thermal energy density budget. We conjecture that the most likely driver for the required heating process is turbulence. Our results are consistent with the known non-adiabatic polytropic index of the electrons, which we measure as 1.176 in the explored range of heliocentric distances.

While dry mergers can produce considerable scatter in the (black hole mass, $M_{\rm bh}$)-(spheroid stellar mass, $M_{\rm *,sph}$) and $M_{\rm bh}$-(spheroid half-light radius, $R_{\rm e,sph}$) diagrams, the virial theorem is used here to explain why the scatter about the $M_{\rm bh}$-(velocity dispersion, $\sigma$) relation remains low in the face of such mergers. Its small scatter has been claimed as evidence of feedback from active galactic nuclei (AGNs). However, it is shown that galaxy mergers also play a significant role. The major merger of two S0 galaxies with $M_{\rm *,sph}\sim10^{11}$ M$_\odot$ advances a system along a slope of $\sim$5 in the $M_{\rm bh}$-$\sigma$ diagram. However, a major E$+$E galaxy merger moves a system (slightly) along a trajectory with a slope of $\sim$9, while mergers of lower-mass S0 galaxies with $M_{\rm *,sph}\sim10^{10}$ M$_\odot$ move (slightly) along a trajectory with a slope of $\sim$3. This produces a steeper distribution for the E (and Es,e) galaxies in the $M_{\rm bh}$-$\sigma$ diagram, reported here to have a slope of 7.27$\pm$0.91, compared to the S0 galaxies which have a slope of 5.68$\pm$0.60. This result forms an important complement to the AGN feedback models like that from Silk and Rees, providing a more complete picture of galaxy/(black hole) coevolution. It also has important implications for nanohertz gravitational wave research. Abridged.

The morpho-kinematics of the circumstellar envelope of oxygen-rich AGB star R Leonis is probed using ALMA (Atacama Large Millimeter/submillimeter Array) observations of the emission of molecular lines, including in particular CO(2-1) and $^{29}$SiO(5-4). Evidence is found for an episode of enhanced mass loss, a few centuries ago, that produced a broad expanding shell of mean radius $\sim$6 arcsec and mean radial expansion velocity $\sim$5.5 km s$^{-1}$ . Detailed scrutiny of its structure, as displayed by the emission of the CO(2-1) line, reveals strong inhomogeneity and patchy morphology. Evidence is also found, in particular from the morpho-kinematics of the emission of SiO, SO and SO$_2$ lines probing the close neighbourhood of the star, for distinct gas outflows covering broad solid angles in the south-eastern, south-western and north-western quadrants, suggesting significant contribution of the convective cell granulation in defining the pattern of mass ejection. A study of relative molecular abundances in these outflows suggests that a Local Thermal Equilibrium (LTE) description applies approximately beyond $\sim$10 stellar radii from the centre of the star but not at the smaller angular separations where the SO and SO$_2$ molecules are found to be confined. Near the stellar disc, masers of the vibrationally excited SiO lines are found to probe north-western parts of a layer of hot gas, consistent with the earlier observation of an asymmetric expanding shell within 1-2 stellar radii from the centre of the star. Globally, a picture dominated by episodic and patchy mass ejections is found to prevail.

The dispersion measure (DM)--redshift relation of fast radio bursts (FRBs) has been proposed as a potential new tool for probing intergalactic medium (IGM) and for studying cosmology. However, the poor knowledge of the baryon fraction in the IGM ($f_{\mathrm{IGM}}$) and its degeneracy with cosmological parameters impose restrictions on the cosmological applications of FRBs. Furthermore, DMs contributed by the IGM ($\mathrm{DM_{IGM}}$) and host galaxy ($\mathrm{DM_{host}}$), the important cosmological quantities, cannot be exactly extracted from observations, which would bring uncontrolled systematic uncertainties in FRB cosmology. In this work, we use seventeen localized FRBs to constrain $f_{\mathrm{IGM}}$ and possibly its redshift evolution. Other cosmological probes such as Type Ia supernovae, baryon acoustic oscillations, and cosmic microwave background radiation are combined to break parameter degeneracy. Taking into account the probability distributions of $\mathrm{DM_{IGM}}$ and $\mathrm{DM_{host}}$ derived from the the IllustrisTNG simulation, we obtain a robust measurement of $f_{\mathrm{IGM}}=0.857\pm0.060$, representing a precision of 7.0\%. We find that there is no strong evidence for the redshift dependence of $f_{\mathrm{IGM}}$ at the current observational data level. The rapid progress in localizing FRBs will significantly improve the constraints on $f_{\mathrm{IGM}}$.

Although only a small fraction of stars end their lives as supernovae, all supernovae leave behind a supernova remnant (SNR), an expanding shock wave that interacts with the surrounding medium, heating the gas and seeding the cosmos with elements forged in the progenitor In this chapter, we introduce the basic properties of galactic and extragalactic SNRs (Section 2). We summarize how SNRs evolve throughout their life cycles over the course of ~10^6 yrs (Section 3). We discuss the various morphological types of SNRs and discuss the emission processes at various wavelengths.(Section 4).

Asteroids are an indelible part of most astronomical surveys though only a few surveys are dedicated to their detection. Over the years, high cadence microlensing surveys have amassed several terabytes of data while scanning primarily the Galactic Bulge and Magellanic Clouds for microlensing events and thus provide a treasure trove of opportunities for scientific data mining. In particular, numerous asteroids have been observed by visual inspection of selected images. This paper presents novel deep learning-based solutions for the recovery and discovery of asteroids in the microlensing data gathered by the MOA project. Asteroid tracklets can be clearly seen by combining all the observations on a given night and these tracklets inform the structure of the dataset. Known asteroids were identified within these composite images and used for creating the labelled datasets required for supervised learning. Several custom CNN models were developed to identify images with asteroid tracklets. Model ensembling was then employed to reduce the variance in the predictions as well as to improve the generalisation error, achieving a recall of 97.67%. Furthermore, the YOLOv4 object detector was trained to localize asteroid tracklets, achieving a mean Average Precision (mAP) of 90.97%. These trained networks will be applied to 16 years of MOA archival data to find both known and unknown asteroids that have been observed by the survey over the years. The methodologies developed can be adapted for use by other surveys for asteroid recovery and discovery.

The persistence of planetary systems after their host stars evolve into their post-main sequence phase is poorly constrained by observations. Many young white dwarf systems exhibit infrared excess emission and/or spectral absorption lines associated with a reservoir of dust (or planetesimals) and its accretion. However, most white dwarfs are too cool to sufficiently heat any circumstellar dust to detectable levels of emission. The Helix Nebula (NGC 7293) is a young, nearby planetary nebula; observations at mid- and far-infrared wavelengths revealed excess emission associated with its central white dwarf (WD 2226-210). The origin of this excess is ambiguous. It could be a remnant planetesimal belt, a cloud of comets, or the remnants of material shed during the post-asymptotic giant branch phase. Here we combine infrared (SOFIA, Spitzer, Herschel ) and millimetre (ALMA) observations of the system to determine the origin of this excess using multi-wavelength imaging and radiative transfer modelling. We find the data are incompatible with a compact remnant planetesimal belt or post-asymptotic giant branch disc, and conclude the dust most likely originates from deposition by a cometary cloud. The measured dust mass, and lifetime of the constituent grains, implies disruption of several thousand Hale-Bopp equivalent comets per year to fuel the observed excess emission around the Helix Nebula's white dwarf.

Relativistic jets are observed around accreting black holes, from stellar mass to super massive black holes. But Its origin has not been fully understood. Although Blanford-Payne process has been considered as most reliable theory of jet production It has no observational proof or supports. In this problem, We suggested the way to display that Bardeen-Petterson effect can become a supporter as providing observational idea of Blanford-Payne process. And we studied black hole jet production by Blanford-Payne process and Bardeen-Peterson effect. As a result, we could calculate observable timescale of black hole jet preccetion

Solar activity is usually caused by the evolution of solar magnetic fields. Magnetic field parameters derived from photospheric vector magnetograms of solar active regions have been used to analyze and forecast eruptive events such as solar flares and coronal mass ejections. Unfortunately, the most recent solar cycle 24 was relatively weak with few large flares, though it is the only solar cycle in which consistent time-sequence vector magnetograms have been available through the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) since its launch in 2010. In this paper, we look into another major instrument, namely the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO) from 1996 to 2010. The data archive of SOHO/MDI covers more active solar cycle 23 with many large flares. However, SOHO/MDI data only has line-of-sight (LOS) magnetograms. We propose a new deep learning method, named MagNet, to learn from combined LOS magnetograms, Bx and By taken by SDO/HMI along with H-alpha observations collected by the Big Bear Solar Observatory (BBSO), and to generate vector components Bx' and By', which would form vector magnetograms with observed LOS data. In this way, we can expand the availability of vector magnetograms to the period from 1996 to present. Experimental results demonstrate the good performance of the proposed method. To our knowledge, this is the first time that deep learning has been used to generate photospheric vector magnetograms of solar active regions for SOHO/MDI using SDO/HMI and H-alpha data.

We report the properties of molecular gas in a sample of six host galaxies of fast radio bursts (FRBs) obtained from CO observations with the Atacama Large Millimeter/submillimeter Array (FRBs 20180924B, 20190102C, and 20190711A) and results of one non-detection in a dwarf galaxy (FRB20121102A) and two events detected in M81 (FRB20200120E) and the Milky Way (FRB20200428A). The CO observations resulted in the detection of CO(3-2) emission in the FRB20180924B host and non-detections of CO(3-2) and CO(2-1) emission in the hosts of FRB20190102C and FRB20190711A, respectively. The derived molecular gas mass and 3$\sigma$ upper limit is $(2.4 \pm 0.2) \times 10^9$ $M_{\odot}$, $<3.8 \times 10^8$ $M_{\odot}$, and $<6.7 \times 10^9$ $M_{\odot}$ for the hosts of FRB20180924B, FRB20190102C, and FRB20190711A, respectively. We found diversity in molecular gas properties (gas mass, gas depletion time, and gas fraction to stellar mass) in the sample. Compared to other star-forming galaxies, the FRB20180924B host is gas-rich (the larger molecular gas fraction), and the hosts of FRB20190102C and FRB20200120E are gas-poor with a shorter depletion time for their stellar mass and star-formation rate. Our findings suggest that FRBs arise from multiple progenitors or single progenitors that can exist in a wide range of galaxy environments. Statistical analysis shows a significant difference in the distribution of molecular gas fraction between the FRB hosts and local star-forming galaxies. However, the difference is not substantial when an outlier, the FRB20200120E host, is excluded, and analysis with a larger sample is needed.

We present observational results of water vapor maser emission with our high-sensitivity 22 GHz VLBI imaging of the Seyfert galaxy NGC 1068. In this galaxy, there are the following four nuclear radio sources; NE, C, S1, and S2. Among them, the S1 component has been identified as the nucleus while the C component has been considered as attributed to the radio jet. In our VLBI observation, we find the following two types of the water maser emission at the S1 component. One is the linearly aligned component that is considered as an edge-on disk with the inner radius of 0.62 pc. The dynamical mass enclosed within the inner radius was estimated to be $1.5\times10^7 M_{\odot}$ by assuming the circular Keplerian motion. Note, however, that the best fit rotation curve shows a sub-Keplerian rotation ($v\propto r^{-0.24\pm0.10}$). The other is the water maser emission distributed around the rotating disk component up to 1.5 pc from the S1 component, suggesting the bipolar outflow from the S1 component. Further, we detected the water maser emission in the C component for the first time with VLBI, and discovered a ring-like distribution of the water maser emission. It is known that a molecular cloud is associated with the C component (both HCN and HCO$^+$ emission lines are detected by ALMA). Therefore, the ring-like maser emission can be explained by the jet collision to the molecular cloud. However, if these ring-like water masing clouds constitute a rotating ring around the C component, it is likely that the C component also has a supermassive black hole with the mass of $\sim 10^6 M_{\odot}$ that could be supplied from a past minor merger of a nucleated satellite galaxy.

We present the discovery of CWISE J151044.74$-$524923.5, a wide low-mass companion to the nearby ($\sim$24.7 pc) system L 262-74, which was identified through the Backyard Worlds: Planet 9 citizen science project. We detail the properties of the system, and we assess that this companion is a mid-L dwarf, which will need to be verified spectroscopically. With an angular separation of 74\farcs3, we estimate a projected physical separation of $\sim$1837 au from the central system.

The origin of the Lyman-${\alpha}$ (Ly${\alpha}$) emission in galaxies is a long-standing issue: despite several processes known to originate this line (e.g. AGN, star formation, cold accretion, shock heating), it is difficult to discriminate among these phenomena based on observations. Recent studies have suggested that the comparison of the ultraviolet (UV) and optical properties of these sources could solve the riddle. For this reason, we investigate the rest-frame UV and optical properties of A2895b, a strongly lensed Ly${\alpha}$-emitter at redshift z ~ 3.7. From this study, we find that our target is a compact (r ~ 1.2 pkpc) star-forming (star formation rate ~ 11 M$_{\odot}$/yr) galaxy having a young stellar population. Interestingly, we measure a high ratio of the H${\beta}$ and the UV continuum monochromatic luminosities (L(H${\beta}$)/L(UV) ~ 100). Based on tracks of theoretical stellar models (Starburst99, BPASS), we can only partially explain this result by assuming a recent (< 10 Myr), bursty episode of star-formation and considering models characterised by binary stars, a top-heavy initial-mass function (IMF) and sub-solar metallicities (Z < 0.01 Z$_{\odot}$). These assumptions also explain the observed low (C/O) abundance of our target (~ 0.23(C/O)$_{\odot}$). By comparing the UV and optical datasets, we find that the Ly${\alpha}$ and UV continuum are more extended (x2) than the Balmer lines, and that the peak of the Ly${\alpha}$ is offset (~ 0.6 pkpc). The multi-wavelength results of our analysis suggest that the observed Ly${\alpha}$ emission originates from a recent star-formation burst, likely taking place in an off-centre clump.

In 2019 a claim was made that the CNEOS 2014-01-08 meteor is interstellar. However, apparent interstellar meteors have been detected for decades. Moreover, they are expected from any meteor observation survey, as a natural consequence of measurement error propagation. Here we examine if enough scientific data were published to identify the orbital and physical nature of CNEOS 2014-01-08. Given the lack of proof regarding the accuracy of the observation, the derivation of the trajectory, velocity and tensile strength, and given the current state of meteor observations and reduction tools, we find no scientific ground to conclude about the interstellar orbit nor the physical properties of CNEOS 2014-01-08. Moreover, given the current data release of this object, to find any piece at the bottom of the ocean seems extremely unlikely.

Hydronium (H$_3$O$^+$) was first detected in 1986 in interstellar molecular clouds. It was reported in many galactic diffuse and dense regions, as well as in extragalactic sources. H$_3$O$^+$ plays a major role both in interstellar oxygen and water chemistry. However, despite the large number of H$_3$O$^+$ observations, its collisional excitation was investigated only partially. In the present work we study the state-to-state rotational de-excitation of $ortho$- and $para$-H$_3$O$^+$ in collisions both with $ortho$- and $para$-H$_2$. The cross sections are calculated within the close-coupling formalism using a highly accurate potential energy surface developed for this system. The rate coefficients are computed up to $300$ K kinetic temperature. Transitions between the lowest 21 rotation-inversion states were studied for $para$-H$_3$O$^+$, and the lowest 11 states for $ortho$-H$_3$O$^+$, i.e. all levels with rotational energies below 430 K ($\sim 300$ cm$^{-1}$) are considered (up to $j\leq5$). In order to estimate the impact of the new rate coefficients on the astrophysical models for H$_3$O$^+$, radiative transfer calculations were also carried out. We have examined how the new collisional data affect the line intensities with respect to older data previously used for the interpretation of observations. By analysing all detected transitions we find that our new, accurate rate coefficients have a significant impact (typically within a factor of 2) on radiation temperatures, allowing more accurate estimation of column densities and relative abundances of hydronium, especially in warm molecular clouds, paving the path towards better interpretation of interstellar water and oxygen chemistry.

We investigate the gravitational instability (GI) of dust-ring structures and the formation of planetesimals by their gravitational collapse. The normalized dispersion relation of a self-gravitating ring structure includes two parameters that are related to its width and line mass (the mass per unit length). We survey these parameters and calculate the growth rate and wavenumber. Additionally, we investigate the planetesimal formation by growth of the GI of the ring that is formed by the growth of the secular GI of the protoplanetary disk. We adopt a massive, dust rich disk as a disk model. We find the range of radii for the fragmentation by the ring GI as a function of the width of the ring. The inner-most radius for the ring GI is smaller for the smaller ring width. We also determine the range of the initial planetesimal mass resulting from the fragmentation of the ring GI. Our results indicate that the planetesimal mass can be as large as 10^28 g at its birth after the fragmentation. It can be as low as about 10^25 g if the ring width is 0.1% of the ring radius and the lower limit increases with the ring width. Furthermore, we obtain approximate formulas for the upper and lower limits of the planetesimal mass. We predict that the planetesimals formed by the ring GI have prograde rotations because of the Coriolis force acting on the contracting dust. This is consistent with the fact that many trans-Neptunian binaries exhibit prograde rotation.

The existence of the million-degree corona above the cooler photosphere is an unsolved problem in astrophysics. Detailed study of quiescent corona that exists regardless of the phase of the solar cycle may provide fruitful hints towards resolving this conundrum. However, the properties of heating mechanisms can be obtained only statistically in these regions due to their unresolved nature. Here, we develop a two-step inversion scheme based on the machine learning scheme of Upendran & Tripathi (2021a) for the empirical impulsive heating model of Pauluhn & Solanki (2007), and apply it to disk integrated flux measurements of the quiet corona as measured by the X-ray solar monitor (XSM) onboard Chandrayaan - 2. We use data in three energy passbands, viz., 1 - 1.3 keV, 1.3 - 2.3 keV, and 1 - 2.3 keV, and estimate the typical impulsive event frequencies, timescales, amplitudes, and the distribution of amplitudes. We find that the impulsive events occur at a frequency of $\approx$25 events per minute with a typical lifetime of $\approx10$ minutes. They are characterized by a power law distribution with a slope $\alpha\leq2.0$. The typical amplitudes of these events lie in an energy range of $10^{21}$ - $10^{24}$ ergs, with a typical radiative loss of about $\approx10^3$ erg cm$^{-2}$ s$^{-1}$ in the energy range of 1 - 2.3 keV. These results provide further constraints on the properties of sub-pixel impulsive events in maintaining the quiet solar corona.

The separation of a filament and sigmoid is observed during an X1.4 flare on July 12, 2012 in solar active region 11520, but the corresponding magnetic field change is not clear. We construct a data-constrained magnetohydrodynamic simulation of the filament-sigmoid system with the flux rope insertion method and magnetic flux eruption code, which produces the magnetic field evolution that may explain the separation of the low-lying filament and high-lying hot channel (sigmoid). The initial state of the magnetic model contains a magnetic flux rope with a hyperbolic flux tube, a null point structure and overlying confining magnetic fields. We find that the magnetic reconnections at the null point make the right footpoint of the sigmoid move from one positive magnetic polarity (P1) to another (P3). The tether-cutting reconnection at the hyperbolic flux tube occurs and quickly cuts off the connection of the low-lying filament and high-lying sigmoid. In the end, the high-lying sigmoid erupts and grows into a coronal mass ejection, while the low-lying filament stays stable. The observed double J-shaped flare ribbons, semi-circular ribbon, and brightenings of several loops are reproduced in the simulation, where the eruption of the magnetic flux rope includes the impulsive acceleration and propagation phases.

Stars that are tidally disrupted by the massive black hole (MBH) may contribute significantly to the growth of the MBH, especially in dense nuclear star clusters (NSCs). Yet, this tidal disruption accretion (TDA) of stars onto the MBH has largely been overlooked compared to the gas accretion (GA) channel in most numerical experiments until now. In this work, we implement a black hole growth channel via TDA in the high-resolution adaptive mesh refinement code Enzo to investigate its influence on a MBH seed's early evolution. We find that a MBH seed grows rapidly from $10^3\,\mathrm{M}_\odot$ to $\gtrsim 10^6\,\mathrm{M}_\odot$ in 200\,Myrs in some of the tested simulations. Compared to a MBH seed that grows only via GA, TDA can enhance the MBH's growth rate by up to more than an order of magnitude. However, as predicted, TDA mainly helps the early growth of the MBH (from $10^{3-4}\,\mathrm{M}_\odot$ to $\lesssim10^{5}\,\mathrm{M}_\odot$) while the later evolution is generally dominated by GA. We also observe that the star formation near the MBH is suppressed when TDA is most active, sometimes with a visible cavity in gas (of size $\sim$ a few pc) created in the vicinity of the MBH. It is because the MBH may grow expeditiously with both GA and TDA, and the massive MBH could consume its neighboring gas faster than being replenished by gas inflows. Our study demonstrates the need to consider different channels of black hole accretion that may provide clues for the existence of supermassive black holes at high redshifts.

We present our final study of the white dwarf cooling sequence (WD CS) in the globular cluster NGC 6752. The investigation is the main goal of a dedicated Hubble Space Telescope large Program, for which all the observations are now collected. The WD CS luminosity function (LF) is confirmed to peak at m_F606W = 29.3+/-0.1, consistent within uncertainties with what has been previously reported, and is now complete down to m_F606W~29.7. We have performed robust and conclusive comparisons with model predictions that show how the theoretical LF for hydrogen envelope WD models closely follow the shape of the empirical LF. The magnitude of the peak of the observed LF is matched with ages between 12.7 and 13.5 Gyr, consistent with the cluster age derived from the main sequence turn off and subgiant branch. We also find that the impact of multiple populations within the cluster on the WD LF for m_F606W below 27.3 is negligible, and that the presence of a small fraction of helium envelope objects is consistent with the data. Our analysis reveals a possible hint of an underestimate of the cooling timescales of models in the magnitude range 28.1 < m_F606W < 28.9. Finally, we find that hydrogen envelope models calculated with a new tabulation of electron conduction opacities in the transition between moderate and strong degeneracy provide WD ages that are too small in comparison to the Main Sequence turnoff age.

We present an analysis of the outer Galaxy giant molecular filament (GMF) G214.5-1.8 (G214.5) using Herschel data. We find that G214.5 has a mass of $\sim$ 16,000 M$_{\odot}$, yet hosts only 15 potentially protostellar 70 $\mu$m sources, making it highly quiescent compared to equally massive clouds such as Serpens and Mon R2. We show that G214.5 has a unique morphology, consisting of a narrow `Main filament' running north-south and a perpendicular `Head' structure running east-west. We identify 33 distinct massive clumps from the column density maps, 8 of which are protostellar. However, the star formation activity is not evenly spread across G214.5 but rather predominantly located in the Main filament. Studying the Main filament in a manner similar to previous works, we find that G214.5 is most like a 'Bone' candidate GMF, highly elongated and massive, but it is colder and narrower than any such GMF. It also differs significantly due to its low fraction of high column density gas. Studying the radial profile, we discover that G214.5 is highly asymmetric and resembles filaments which are known to be compressed externally. Considering its environment, we find that G214.5 is co-incident, spatially and kinematically, with a HI superbubble. We discuss how a potential interaction between G214.5 and the superbubble may explain G214.5's morphology, asymmetry and, paucity of dense gas and star formation activity, highlighting the intersection of a bubble-driven interstellar medium paradigm with that of a filament paradigm for star formation.

We study a generalized version of hilltop inflation where the standard hilltop potential has been raised to a power and we allow fractional numbers for both the original hilltop power and the overall exponent. In the parameter space studied, the latter plays the major role in finding an agreement with the latest experimental constraint. Finally, we also find that the two characteristic mass scales of the inflaton potential differ by several orders of magnitude, indicating that a common fundamental origin is quite unlikely.

In this study, we report on the analysis of 701 stars in a solar vicinity defined in three categories namely subsolar, solar, and supersolar with rotation periods between 1 and 70 days, based on rotational modulation signatures inferred from time series from the Kepler mission's Public Archives. In our analysis, we performed an initial selection based on the rotation period and position in the period-H diagram, where H denotes the Hurst exponent extracted from fractal analysis. To refine our analysis, we applied a fractal approach known as the R/S method, taking into account the fluctuations of the features associated with photometric modulation at different time intervals and the fractality traces that are present in the time series of our sample. In this sense, we computed the so-called Hurst exponent for the referred stars and found that it can provide a strong discriminant of rotational modulation and background noise behavior, going beyond what can be achieved with solely the rotation period itself. Furthermore, our results emphasize that the rotation period of stars is scaled by the exponent H which increases following the increase in the rotation period. Finally, our approach suggests that the referred exponent may be a powerful rotational modulation and noise classifier.

With advance of supercomputers we can now afford simulations with very large range of scales. In astrophysical applications, e.g. simulating Solar, stellar and planetary atmospheres, physical quantities, like gas pressure, density, temperature and plasma $\beta$ can vary by orders of magnitude. This requires a robust solver, which can deal with a very wide range of conditions and be able to maintain hydrostatic equilibrium. We reformulate a Godunov-type HLLD Riemann solver so it would be suitable to maintain hydrostatic equilibrium in atmospheric applications and would be able to handle low and high Mach numbers, regimes where kinetic and magnetic energies dominate over thermal energy without any ad-hoc corrections. We change the solver to use entropy instead of total energy as the 'energy' variable in the system of MHD equations. The entropy is *not conserved*, it increases when kinetic and magnetic energy is converted to heat, as it should. We conduct a series of standard tests with varying conditions and show that the new formulation for the Godunot type Riemann solver works and is very promising.

For building the super-massive black hole population within a Hubble time, only sub-populations with more than 10^52 erg/s / L objects on the sky are relevant, where L is the sample-averaged luminosity.

In this paper, we calibrate the Amati relation (the $E_{\rm p}$-$E_{\rm iso}$ correlation) of gamma-ray bursts (GRBs) in a cosmology-independent way. By using Gaussian process to reconstruct the smoothed luminosity distance from the Pantheon type Ia supernovae (SNe Ia) sample, we utilize the reconstructed results to calibrate the $E_{\rm p}$-$E_{\rm iso}$ correlation with the Markov Chain Monte Carlo method and construct a Hubble diagram with the A220 GRB data, in which A118 GRB data with the higher qualities appropriate for cosmological purposes. With 98 GRBs at $1.4<z\leq8.2$ in A118 sample and the observed Hubble data, we obtain $\Omega_m$ = $0.346^{+0.048}_{-0.069}$, $h$ = $0.677^{+0.029}_{-0.029}$ for the flat $\Lambda$CDM model, and $\Omega_m$ = $0.314^{+0.072}_{-0.055}$, $h$ = $0.705^{+0.055}_{-0.069}$, $w$ = $-1.23^{+0.33}_{-0.64}$ for the flat $w$CDM model, which are consistent with those from fitting the coefficients of the Amati relation and the cosmological parameters simultaneously.

TXS 0506+056, a source of the extreme energy neutrino event, IceCube-170922A, was observed on 22 September 2017. The Fermi-LAT detector reported high energy (HE) $\gamma$-ray flare between 100 MeV and 100 GeV starting from 15 September 2017 from this source. Several attempts to trace the very high energy (VHE) gamma-ray counterparts around the IceCube-170922A resulted in no success. Only after 28 September, the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes observed the first VHE gamma-rays from the blazar above 100 GeV. The $\sim$ 41 hr survey resulted in VHE-$\gamma$ ray activity till 31 October 2017. Here we propose the extended GeV $\gamma-$rays can be explained by taking two production channels, electron synchrotron self Compton and proton synchrotron for HE and VHE emissions, respectively. The 45 days of VHE emission from the peak of the HE-flare can be explained with $ {L_p'}{\simeq}10^{47}$ erg/sec in the jet frame and magnetic field of 2.4 G, consistent with the ${L}_{Edd}$ for a blackhole mass $5\times 10^{9} {M}_\odot$

We present the data release and data reduction process for the Epoch 1 NIRCam observations for the Cosmic Evolution Early Release Science Survey (CEERS). These data consist of NIRCam imaging in six broadband filters (F115W, F150W, F200W, F277W, F356W and F444W) and one medium band filter (F410M) over four pointings, obtained in parallel with primary CEERS MIRI observations (Yang et al. in prep). We reduced the NIRCam imaging with the JWST Calibration Pipeline, with custom modifications and reduction steps designed to address additional features and challenges with the data. Here we provide a detailed description of each step in our reduction and a discussion of future expected improvements. Our reduction process includes corrections for known pre-launch issues such as 1/f noise, as well as in-flight issues including snowballs, wisps, and astrometric alignment. Many of our custom reduction processes were first developed with pre-launch simulated NIRCam imaging over the full 10 CEERS NIRCam pointings. We present a description of the creation and reduction of this simulated dataset in the Appendix. We provide mosaics of the real images in a public release, as well as our reduction scripts with detailed explanations to allow users to reproduce our final data products. These represent one of the first official public datasets released from the Directors Discretionary Early Release Science (DD-ERS) program.

Molecular lines tracing the orbital motion of gas in a well-defined disk are valuable tools for inferring both the properties of the disk and the star it surrounds. Lines that arise only from a disk, and not also from the surrounding molecular cloud core that birthed the star or from the outflow it drives, are rare. Several such emission lines have recently been discovered in one example case, those from NaCl and KCl salt molecules. We studied a sample of 23 candidate high-mass young stellar objects (HMYSOs) in 17 high-mass star-forming regions to determine how frequently emission from these species is detected. We present five new detections of water, NaCl, KCl, PN, and SiS from the innermost regions around the objects, bringing the total number of known briny disk candidates to nine. Their kinematic structure is generally disk-like, though we are unable to determine whether they arise from a disk or outflow in the sources with new detections. We demonstrate that these species are spatially coincident in a few resolved cases and show that they are generally detected together, suggesting a common origin or excitation mechanism. We also show that several disks around HMYSOs clearly do not exhibit emission in these species. Salty disks are therefore neither particularly rare in high-mass disks, nor are they ubiquitous.

Recently, a population of compact main sequence (MS) galaxies exhibiting starburst-like properties have been identified in the GOODS-ALMA blind survey at 1.1mm. Several evolution scenarios were proposed to explain their particular physical properties (e.g., compact size, low gas content, short depletion time). In this work, we aim at studying the star formation history (SFH) of the GOODS-ALMA galaxies to understand if the so-called ``starburst (SB) in the MS'' galaxies exhibit a different star formation activity over the last Gyr compared to MS galaxies that could explain their specificity. We use the CIGALE SED modelling code to which we add non-parametric SFHs. To compare quantitatively the recent SFH of the galaxies, we define a parameter, the star formation rate (SFR) gradient that provides the angle showing the direction that a galaxy has followed in the SFR vs stellar mass plane over a given period. We show that ``SB in the MS'' have positive or weak negative gradients over the last 100, 300, and 1000 Myr, at odds with a scenario where these galaxies would be transitioning from the SB region at the end of a strong starburst phase. Normal GOODS-ALMA galaxies and ``SB in the MS'' have the same SFR gradients distributions meaning that they have similar recent SFH, despite their different properties (compactness, low depletion time). The ``SBs in the MS'' manage to maintain a star-formation activity allowing them to stay within the MS. This points toward a diversity of galaxies within a complex MS.

Analysis of Chandra observations of the neutron star (NS) in the centre of the Cassiopeia A supernova remnant taken in the subarray (FAINT) mode of the ACIS detector performed by Posselt and collaborators revealed, after inclusion of the most recent (May 2020) observations, a significant decrease of the source surface temperature from 2006 to 2020. The obtained cooling rate is consistent with those obtained from analysis of the 2000$-$2019 data taken in the GRADED mode of the ACIS detector, which is potentially more strongly affected by instrumental effects. We performed a joint spectral analysis using all ACIS data to constrain the NS parameters and cooling rate. We constrain the mass of the Cassiopeia A NS at $M=1.55\pm0.25~M_\odot$, and its radius at $R=13.5\pm 1.5$ km. The surface temperature cooling rate is found to be $2.2\pm 0.3$ per cent in 10 years if the absorbing hydrogen column density is allowed to vary and $1.6\pm 0.2$ per cent in 10 years if it is fixed. The observed cooling can be explained by enhanced neutrino emission from the superfluid NS interior due to Cooper Pair Formation (CPF) process. Based on analysis of all ACIS data, we constrain the maximal critical temperature of triplet neutron pairing within the NS core at $(4-9.5)\times 10^{8}$ K. In accordance with previous studies, the required effective strength of the CPF neutrino emission is at least a factor of 2 higher than existing microscopic calculations suggest.

We show that fuzzy dark matter halos exhibit spatial differentiation in the degree of coherence of the field configuration, ranging from completely coherent in the central solitonic core to incoherent outside it, with a crossover region in between the two phases. The solitonic core is indeed a pure condensate which overlaps almost perfectly with the Penrose-Onsager mode corresponding to the largest eigenvalue of the one-particle density matrix. The virialized outer halo surrounding the core exhibits no clear coherence as a whole upon radial and temporal averaging. However, when viewed locally and for short times, it can be described as a collection of quasi-condensate lumps exhibiting locally suppressed fluctuations which can be identified with the structures commonly referred to as granules. Phase coherence across the entire halo is inhibited by a dynamically evolving tangled web of vortices separating the localized quasi-condensate regions. Moreover, the dimensionless phase-space density in the outer halo drops significantly below its value at the core. We further examine the dynamics of this spatial structure and find that the oscillations of the core can be accurately described by two time-dependent parameters respectively characterizing the size of the core, $r_c(t)$, and the crossover region, $r_t(t)$. For the halos produced in our merger simulations this feature is reflected in the (anti-)correlated oscillation of the peak value of the field configuration's power-spectrum. The turbulent vortex tangle of the virialized halo appears to reach a quasi-equilibrium state over probed timescales, with the incompressible component of the kinetic energy exhibiting a characteristic $k^{-3}$ tail in its spectrum, indicative of a $\rho\sim r^2$ density profile around the quantum vortex cores. Comparison of the peak wavenumbers in the corresponding power-spectra shows that the inter-vortex...

Interplanetary Coronal Mass Ejections (ICMEs) originate from the eruption of complex magnetic structures occurring in our star's atmosphere. Determining the general properties of ICMEs and the physical processes at the heart of their interactions with the solar wind is a hard task, in particular using only unidimensional in situ profiles. Thus, these phenomena are still not well understood. In this study we simulate the propagation of a set of flux ropes in order to understand some of the physical processes occurring during the propagation of an ICME such as their growth or their rotation. We present simulations of the propagation of a set of flux ropes in a simplified solar wind. We consider different magnetic field strengths and sizes at the initiation of the eruption, and characterize their influence on the properties of the flux ropes during their propagation. We use the 3D MHD module of the PLUTO code on an Adaptive Mesh Refinement grid. The evolution of the magnetic field of the flux rope during the propagation matches evolution law deduced from in situ observations. We also simulate in situ profiles that spacecraft would have measured at the Earth, and we compare with the results of statistical studies. We find a good match between simulated in situ profiles and typical profiles obtained in these studies. During their propagation, flux ropes interact with the magnetic field of the wind but still show realistic signatures of ICMEs when analyzed with synthetic satellite crossings. We also show that flux ropes with different shapes and orientations can lead to similar unidimensional crossings. This warrants some care when extracting magnetic topology of ICMEs using unidimensional crossings.

Inflationary models predicting a scale-dependent large amplification of the density perturbations have recently attracted a lot of attention because the amplified perturbations can seed a sizable amount of primordial black holes (PBHs) and stochastic background of gravitational waves (GWs). While the power spectra in these models are computed based on the linear equation of motion, it is not obvious whether loop corrections are negligible when such a large amplification occurs during inflation. In this paper, as a first step to discuss the loop corrections in such models, we use the in-in formalism and calculate the one-loop scalar power spectrum numerically and analytically in an illustrative model where the density perturbations are resonantly amplified due to oscillatory features in the inflaton potential. Our calculation is technically new in that the amplified perturbations are numerically taken into account in the in-in formalism for the first time. In arriving at our analytical estimates, we highlight the role that the Wronskian condition of perturbations, automatically satisfied in our model, plays in obtaining the correct estimates. In addition, the analytical estimates show that the contribution originating from the quantum nature of the perturbations in the loop can be dominant. We also discuss the necessary conditions for subdominant loop corrections in this model. We find that, for the typical parameter space leading to the $\mathcal O(10^7)$ amplification of the power spectrum required for a sufficient PBH production, the one-loop power spectrum dominates over the tree-level one, indicating the breakdown of the perturbation theory.

Aims. Monte Carlo Radiative Transfer (MCRT) simulations are a powerful tool for understanding the role of dust in astrophysical systems and its influence on observations. However, due to the strong coupling of the radiation field and medium across the whole computational domain, the problem is non-local and non-linear and such simulations are computationally expensive in case of realistic 3D inhomogeneous dust distributions. We explore a novel technique for post-processing MCRT output to reduce the total computational run time by enhancing the output of computationally less expensive simulations of lower-quality. Methods. We combine principal component analysis (PCA) and non-negative matrix factorization (NMF) as dimensionality reduction techniques together with Gaussian Markov random fields and the Integrated nested Laplace approximation (INLA), an approximate method for Bayesian inference, to detect and reconstruct the non-random spatial structure in the images of lower signal-to-noise or with missing data. Results. We test our methodology using synthetic observations of a galaxy from the SKIRT Auriga project - a suite of high resolution magneto-hydrodynamic Milky Way-sized galaxies simulated in cosmological environment by 'zoom-in' technique. With this approach, we are able to reproduce high photon number reference images $\sim5$ times faster with median residuals below $\sim20\%$.

The Einstein field equations of general relativity constrain the local curvature at every point in spacetime, but say nothing about the global topology of the Universe. Cosmic microwave background anisotropies have proven to be the most powerful probe of non-trivial topology since, within $\Lambda$CDM, these anisotropies have well-characterized statistical properties, the signal is principally from a thin spherical shell centered on the observer (the last scattering surface), and space-based observations nearly cover the full sky. The most generic signature of cosmic topology in the microwave background is pairs of circles with matching temperature and polarization patterns. No such circle pairs have been seen above noise in the WMAP or Planck temperature data, implying that the shortest non-contractible loop around the Universe through our location is longer than 98.5% of the comoving diameter of the last scattering surface. We translate this generic constraint into limits on the parameters that characterize manifolds with each of the nine possible non-trivial orientable Euclidean topologies, and provide a code which computes these constraints. In all but the simplest cases, the shortest non-contractible loop in the space can be shorter than the diameter of the last scattering surface by a factor ranging from 2 to at least 6. This result implies that a broader range of manifolds is observationally allowed than widely appreciated. Probing these manifolds will require subtler statistical signatures such as off-diagonal correlations of harmonic coefficients.

We present a study of the flux distribution of a sample of 15 Intermediate and Low-energy peaked blazars using XMM-Newton observations in a total of 57 epochs on short-term timescales. We characterise the X-ray variability of all of the light curves using excess fractional variability amplitude and found that only 24 light curves in 7 sources are significantly variable. In order to characterise the origin of X-ray variability in these blazars, we fit the flux distributions of all these light curves using Gaussian and lognormal distributions, as any non-Gaussian perturbation could indicate the imprints of fluctuations in the accretion disc, which could be Doppler boosted through the relativistic jets in blazars. However, intra-day variability, as seen in our observations, is difficult to reconcile using disc components as the emissions in such sources are mostly dominated by jets. We used Anderson-Darling (AD) and $\chi^{2}$ tests to fit the histograms. In 11 observations of 4 blazars, namely, ON 231, 3C 273, PKS 0235+164 and PKS 0521-365, both models equally fit the flux distributions. In the rest of the observations, we are unable to model them with any distribution. In two sources, namely, BL Lacertae and S4 0954+650, the lognormal distribution is preferred over the normal distribution, which could arise from non-Gaussian perturbations from relativistic jets or linear Gaussian perturbation in the particle time scale leading to such flux distributions.

Here we present the first constraints on the prevalence of z>10 galaxies in the Hubble Ultra Deep Field (HUDF) leveraging new NIRCam medium-band observations taken with JWST. These NIRCam observations probe redward of 1.6microns, beyond the wavelength limit of HST, allowing us to search for galaxies to z>10. These observations indicate that the highest redshift candidate identified over the HUDF with HST, UDFj-39546284, has a redshift of z=12.0+/-0.1, as had been suggested in multiple analyses of the HUDF12/XDF data. This source thus appears to be the most distant galaxy discovered by HST in its more than 30 years of operation. Additionally, we identify nine other z~8-13 candidate galaxies over the HUDF, two of which are entirely new discoveries and appear to lie at z~11 and z~12. We use these results to characterize the evolution of the UV luminosity function (LF) from z~15 to z~8.7. While our LF results at z~8.7 and z~10.5 are consistent with previous findings over the HUDF, our new LF estimates at z~12.6 are substantially higher than other results in the literature, potentially pointing to a milder evolution in the UV luminosity density from z~12.6. We emphasize that our LF results are uncertain given the small number of sources in our z~12.6 selection and limited volume probed. The new NIRCam data also indicate that the faint z~8-13 galaxies in the HUDF/XDF show very blue UV-continuum slopes beta~-2.7, high specific star formation rates ~24.5 Gyr$^{-1}$, and high EW (~1300A) [OIII]+Hbeta emission, with two z~8.5 sources showing [OIII]+Hbeta EWs of ~2300 Angstroms.

The James Webb Space Telescope has detected surprisingly luminous early galaxies that indicate a tension with the $\Lambda$CDM. Motivated by scenarios including axion miniclusters or primordial black holes, we consider power-law modifications of the matter power spectrum. We show that the tension could be resolved if dark matter consists of $10^{-18}{\rm eV}$ axions or if a fraction $f_{\rm PBH} > 0.005$ of dark matter is composed of compact heavy $6\times 10^6 M_\odot (f_{\rm PBH}/0.005)^{-1}$ structures such as primordial black hole clusters. However, in both cases, the star formation efficiency needs to be significantly enhanced.

The theory of f(R)-gravity is one of the theories of modified Einstein gravity. The vacuum solution, on the other hand, of the field equation is the solution for black hole geometry. We establish here an asymptotically flat rotating black hole solution in an f(R)-gravity. This essentially leads to the modified solution to the Kerr black hole. This solution exhibits the change in fundamental properties of the black hole and its geometry. It particularly shows that radii of marginally stable and bound orbits and black hole event horizon increase compared to those in Einstein gravity, depending on the modified gravity parameter. It further argues for faster spinning black holes with spin (Kerr) parameter greater than unity, without any naked singularity. This supports the weak cosmic censorship hypothesis.

The Froggatt-Nielsen (FN) mechanism provides an attractive way of generating the determined fermion mass hierarchy and quark mixing matrix elements in the Standard Model (SM). Here we extend it by coupling the FN field, the flavon, to a dark sector containing one or more dark matter particles which are produced non-thermally sequentially through flavon production. Non-thermal flavon production occurs efficiently via freeze-in and through field oscillations. We explore this in the regime of high-scale breaking $\Lambda$ of the global $U(1)_{\textrm{FN}}$ group and at the reheating temperature $T_R\ll \Lambda$ where the flavon remains out of equilibrium at all times. We identify phenomenologically acceptable regions of $T_R$ and the flavon mass where the relic abundance of dark matter and other cosmological constraints are satisfied. In the case of one-component dark matter we find an effective upper limit on the FN charges at high $\Lambda$, i.e. $Q_{\rm FN}^{\rm DM}\leq13$. In the multi-component dark sector scenario the dark particle can be the heaviest dark particle that can be effectively stable at cosmological timescales, alternatively it can be produced sequentially by decays of the heavier ones. For scenarios where dark decays occur at intermediate timescales, i.e. $t\sim 0.1- 10^{28}\,{\rm s}$, we find that existing searches can effectively probe interesting regions of parameter space. These searches include indirect probes on decays such as $\gamma$-ray and neutrino telescopes as well as analyses of the Cosmic Microwave Background, as well as constraints on small scale structure formation from the Lyman-$\alpha$ forest. We comment on the future prospects of such probes and place projected sensitivities.

Rotational superradiance generates the amplification of incoming waves of sufficiently low frequency when scattered with a rotating absorbing body. This may be used to discover new \emph{bosonic} particles of mass $m_b$ if the rotating body has a sufficiently strong gravitational field, that may confine the massive particle and turn amplification into exponential growth. As a result, the initial seed may be amplified until generating a large cloud around the body, which may have a number of phenomenological consequences. Rotating black holes are perfect candidates to source this effect, not only from their absorbing and gravitational properties (and hence confining mechanism), but also because for black holes of mass $M_{\rm BH}$, rotational superradiance is efficient for $m_b\sim 10^{-10}\left(\frac{M_{\odot}}{M_{\rm BH}}\right)\rm eV$. The wide range of astrophysical black hole masses brings about new opportunities to probe particles of low masses in a large span very hard to detect by any other known method. In this brief contribution I will comment on some of these opportunities.

Gravity can be embedded into a renormalizable theory by means of adding quadratic in curvature terms. However, this at first leads to the presence of the Weyl ghost. It is possible to get rid of this ghost if the locality assumption is weakened and the propagator of the graviton is represented by an entire function of the d'Alembertian operator without new poles and zeros. Models of this type admit a cosmological solution describing the $R^2$, or Starobinsky, inflation. We study graviton production after inflation in this model and show that it is negligible despite the presence of the higher derivative operators which could potentially cause instabilities.

We present first-order post-Newtonian (1PN) approximations of a general imperfect fluid and of an axion as a coherently oscillating massive scalar field, both in the cosmological context. For the axion, using the Klein transformation and Madelung transformation we derive the Schr\"odinger and Madelung hydrodynamic formulations, respectively, in exact covariant way and to 1PN order. Complete sets of equations for the 1PN formulations are derived without fixing the temporal gauge condition. We study the linear instability in cosmology and a static limit for both fluid and axion; these are presented independently of the gauge condition to 1PN order, thus are naturally gauge-invariant.

Since the release of the 2015 Long Range Plan in Nuclear Physics, major events have occurred that reshaped our understanding of quantum chromodynamics (QCD) and nuclear matter at large densities, in and out of equilibrium. The US nuclear community has an opportunity to capitalize on advances in astrophysical observations and nuclear experiments and engage in an interdisciplinary effort in the theory of dense baryonic matter that connects low- and high-energy nuclear physics, astrophysics, gravitational waves physics, and data science

The particle showers produced in the atmosphere due to the interactions of primary cosmic particles require a thorough understanding in the backdrop of searches for rare interactions. While the showers encompass the physics of strong, weak and electromagnetic interactions, the very first interactions are strong interactions producing hadronic showers which could introduce uncertainties in the estimates of particle yields. In this work, we made a comprehensive study of air shower simulations using various combinations of hadronic models and particle transport code of the CORSIKA package. The hadronic particles mostly pions and kaons decay to muons which are the most abundant charged particles on Earth. The primary proton and helium distributions are taken as power law which are scaled to match the measured flux in balloon experiments at the top of atmosphere. The shower simulation includes production, transport, and decays of secondaries up to the ground level. In this study, we focus on the bulk of the spectra and particles rather than very high energy showers. We provide a way to normalize the simulation results to be compared with the ground-based measurements namely, single and multiple muon yields and their charge ratios as a function of zenith angle and momentum. This provides a basis for comparisons amoung the six model combinations used in this study and the differences are outlined. Most of the hadronic models in CORSIKA produce the bulk ground based measurements fairly well. We use one of the best model combinations to quantitatively predict the absolute and relative yields of various particles at ground level as well as their correlations with primaries and with each other.

The LISA mission is the future space-based gravitational wave (GW) observatory of the European Space Agency. It is formed by 3 spacecraft exchanging laser beams in order to form multiple real and virtual interferometers. The data streams to be used in order to extract the large number and variety of GW sources are Time-Delay Interferometry (TDI) data. One important processing to produce these data is the TDI on-ground processing which recombines multiple interferometric on-board measurements to remove certain noise sources from the data such as laser frequency noise or spacecraft jitter. The LISA noise budget is therefore expressed at the TDI level in order to account for the different TDI transfer functions applied for each noise source and thus estimate their real weight on mission performance. In order to derive a usable form of these transfer functions, a model of the beams, the measurements, and TDI have been developed, and several approximation have been made. A methodology for such a derivation has been established, as well as verification procedures. It results in a set of transfer functions, which are now used by the LISA project, in particular in its performance model. Using these transfer functions, realistic noise curves for various instrumental configurations are provided to data analysis algorithms and used for instrument design.