Papers for Tuesday, Oct 04 2022

By applying four different methods including equi-zenith angle method, surrounding window method, direct integration method, and time-swapping method, the number of the background events is calculated. Based on simulation samples, the statistical significance of the excess signal from different background methods is determined. After that, we discuss the limits and the applicability of the four background method under different conditions. Under the detector stability assumption with signal, the results from above four methods are consistent within 1{\sigma} level. On no signal condition, when the acceptance of the detector changes with both space and time, the surrounding window method is most stable and hardly affected. In this acceptance assumption, we find that the background estimation in the direct integration method is sensitive to the selection of time integration window, and the time window of 4 hour is more applicable, which can reduce the impact on the background estimation to some extent.

We extend the Ultra-Diffuse Galaxy (UDG) abundance relation, $N_{UDG}-M_{200}$, to lower halo mass hosts $(M_{200}\sim10^{11.6-12.2}M_{\odot})$. We select UDG satellites from published catalogs of dwarf satellite galaxies around Milky Way analogs, namely the Exploration of Local Volume Satellites (ELVES) survey, Satellite Around Galactic Analogs (SAGA) survey, and a survey of Milky Way-like systems conducted using the Hyper-Suprime Cam. Of the 516 satellites around a total of 75 Milky Way-like hosts, we find 41 satellites around 33 hosts satisfy the UDG criteria. The distributions of host halo masses peak around $M_{200}\sim10^{12}M_{\odot}$ independent of whether the host has a UDG satellite or not. We use literature UDG abundances and those derived here to trace the $N_{UDG}-M_{200}$ relation over three orders of magnitude down to $M_{200}=10^{11.6}M_{\odot}$ and find a best-fit linear relation of $N_{UDG} = (37\pm4)\cdot(\frac{M_{200}}{10^{14}})^{0.85\pm0.07}$. This sub-linear slope is consistent with earlier studies of UDG abundances as well as abundance relations for brighter dwarf galaxies, excluding UDG formation mechanisms that require high-density environments. However, we highlight the need for further homogeneous characterization of UDGs across a wide range of environments to properly understand the $N_{UDG}-M_{200}$ relation.

Common-envelope evolution is a stage in binary system evolution in which a giant star engulfs a companion. The standard energy formalism is an analytical framework to estimate the amount of energy transferred from the companion's shrinking orbit into the envelope of the star that engulfed it. We show analytically that this energy transfer is larger than predicted by the standard formalism. As the orbit of the companion shrinks, the mass it encloses becomes smaller, and the companion is less bound than if the enclosed mass had remained constant. Therefore, more energy must be transferred to the envelope for the orbit to shrink further. We derive a revised energy formalism that accounts for this effect, and discuss its consequences in two contexts: the formation of neutron star binaries, and the engulfment of planets and brown dwarfs by their host stars. The companion mass required to eject the stellar envelope is smaller by up to $50\%$, leading to differences in common-envelope evolution outcomes. The energy deposition in the outer envelope of the star, which is related to the transient luminosity and duration, is up to a factor of $\approx7$ higher. Common-envelope efficiency values above unity, as defined in the literature, are thus not necessarily unphysical, and result at least partly from an incomplete description of the energy deposition. The revised energy formalism presented here can improve our understanding of stellar merger and common-envelope observations and simulations.

Supermassive black hole binary systems (SMBHBs) should be the most powerful sources of gravitational waves in the Universe. Once Pulsar Timing Arrays (PTAs) detect the stochastic gravitational-wave background from their cosmic merger history, searching for individually resolvable binaries will take on new importance. Since these individual supermassive black hole binary systems are expected to be rare, here we explore how strong gravitational lensing can act as a tool for increasing their detection prospects by magnifying fainter sources and bringing them into view. We investigate gravitational wave signals from SMBHBs that might be detectable with current and future PTAs under the assumption that quasars serve as bright beacons that signal a recent merger. Using the black hole mass function derived from quasars and assuming fortuitous alignment yielding a high magnification factor of $\mu = 30$, we can expect to detect of the order of 1 strongly lensed binary system out to $z \approx 1.25$. Encouragingly, though, to within $z = 2$, strong lensing adds $\sim$9$-$26 more detectable binaries for PTAs. Finally, we investigate the possibility of observing both time-delayed electromagnetic signals and gravitational wave signals from these strongly lensed binary systems - that will provide us with unprecedented multi-messenger insights into their orbital evolution.

We present a sample of 24 local star-forming galaxies observed with broad- and narrow-band photometry from the Hubble Space Telescope, that are part of the GOALS survey of local luminous and ultra-luminous infrared galaxies. With narrow-band filters around the emission lines H$\alpha$ (and [NII]) and Pa$\beta$, we obtain robust estimates of the dust attenuation affecting the gas in each galaxy, probing higher attenuation than can be traced by the optical Balmer decrement H$\alpha$/H$\beta$ alone by a factor of $>1$ mag. We also infer the dust attenuation towards the stars via a spatially-resolved SED-fitting procedure that uses all available HST imaging filters. We use various indicators to obtain the star formation rate (SFR) per spatial bin, and find that Pa$\beta$ traces star-forming regions where the H$\alpha$ and the optical stellar continuum are heavily obscured. The dust-corrected Pa$\beta$ SFR recovers the 24$\mu$m-inferred SFR with a ratio $-0.14\pm0.32$ dex and the SFR inferred from the $8\mathrm{-}1000\,\mu\mathrm{m}$ infrared luminosity at $-0.04\pm0.23$ dex. Both in a spatially-resolved and integrated sense, rest-frame near infrared recombination lines can paint a more comprehensive picture of star formation across cosmic time, particularly with upcoming JWST observations of Paschen-series line emission in galaxies as early as the epoch of reionization.

Coronal mass ejections (CMEs) are transient solar eruptions of magnetised plasma from the Sun's corona. Their interactions with the geo-magnetosphere may lead to severe geomagnetic perturbations. Such space weather events pose a threat to ground- and space-based technologies thereby impacting modern societal infrastructure. To understand the physical processes behind geomagnetic storms and predict them we develop a new CME flux rope-magnetosphere interaction module using 3D magnetohydrodynamics. Our approach is relatively simpler and time-efficient compared to more complex models but performs well in estimating the strength and temporal variations of geomagnetic storms. Simulated postdictions for two contrasting coronal mass ejections from 2003 and 2006 exhibit strong linear correlation with observed Dst and SYM-H indices. This study paves the way for operationally efficient prediction of CME flux rope driven geomagnetic storms.

We have carried out a new photometric V,Rc study of 12 protoplanetary nebulae, objects in the short-lived transition between the AGB and PN phases of stellar evolution. These had been the subjects of an earlier study, using data from 1994-2007, that found that all 12 varied periodically, with pulsation periods in the range of ~38 to ~150 days. They are all carbon-rich, with F-G spectral types. We combined our new (2008-2018) data with publicly-available ASAS-SN data and determined new periods for their variability. The older and newer period values were compared to investigate evidence of period change, for which there is theoretical support that it might be detectable in a decade or two in some cases. Such a detection is challenging since the light curves are complicated, with multiple periods, changing amplitudes, and evidence of shocks. Nevertheless, we found one, and possibly two, such cases, which are associated with the higher temperature stars in the sample (7250 and 8000 K). These results are most consistent with the evolution of stars at the lower end of the mass range of carbon stars, ~1.5-2 M(sun). Several of the stars show longer-term trends of increasing (six cases) or decreasing (one case) brightness, which we think most likely due to changes in the circumstellar dust opacity. There is one case of a possible ~1.8 yr period in addition to the shorter pulsation. This is interpreted as possible evidence of an orbiting companion.

Magnetars are neutron stars characterized by strong surface magnetic fields generally exceeding the quantum critical value of 44.1 TeraGauss. High-energy photons propagating in their magnetospheres can be attenuated by QED processes like photon splitting and magnetic pair creation. In this paper, we compute the opacities due to photon splitting and pair creation by photons emitted anywhere in the magnetosphere of a magnetar. Axisymmetric, twisted dipole field configurations embedded in the Schwarzschild metric are treated. The paper computes the maximum energies for photon transparency that permit propagation to infinity in curved spacetime. Special emphasis is given to cases where photons are generated along magnetic field loops and/or in polar regions; these cases directly relate to resonant inverse Compton scattering models for the hard X-ray emission from magnetars and Comptonized soft gamma-ray emission from giant flares. We find that increases in magnetospheric twists raise or lower photon opacities, depending on both the emission locale, and the competition between field line straightening and field strength enhancement. Consequently, given the implicit spectral transparency of hard X-ray bursts and persistent "tail" emission of magnetars, photon splitting considerations constrain their emission region locales and the twist angle of the magnetosphere; these constraints can be probed by future soft gamma-ray telescopes such as COSI and AMEGO. The inclusion of twists generally increases the opaque volume of pair creation by photons above its threshold, except when photons are emitted in polar regions and approximately parallel to the field.

We survey the spectro-temporal properties of fast radio bursts from FRB20121102A across a wide range of frequencies. We investigate 167 bursts from FRB20121102A spanning frequencies 1-7.5GHz, durations of less than 1ms to approximately 10ms, with low and high energies, and with wait-times on the order of milliseconds to seconds. We find from our sample of bursts from FRB20121102A a strong agreement with the inverse relationship between sub-burst slope and duration and with other predictions made by the triggered relativistic dynamical model (TRDM). Earlier results found agreement with those predictions across three different repeating FRB sources. For this sample of bursts, we find that the sub-burst slope as well as the `sad trombone' drift rate are consistent with being quadratic with frequency, that both these quantities are inversely proportional to the duration as well as finding that the duration decreases with increasing frequency. We also find a statistically significant correlation between the sub-burst duration and bandwidth (proportional to $t^{-1/2}$) that is unexpected. No distinct group of bursts in this sample deviated from these relationships, however significant dispersion can be seen in measurements. This study demonstrates the consistent existence of relationships between the spectro-temporal properties of bursts from an FRB source, and a simple explanation for the inverse relation between the sub-burst slope and duration is an inherently narrowband emission process. We make available all measurements as well as a graphical user interface called Frbgui developed and used to perform measurements of burst waterfalls.

We present the first direct spectroscopic measurement of the stellar velocity dispersion function (VDF) for massive quiescent and star-forming galaxies at $0.6 < z \leq 1.0$. For this analysis we use individual measurements of stellar velocity dispersion from high-S/N spectra from the public Large Early Galaxy Astrophysics Census (LEGA-C) survey. We report a remarkable stability of the VDF for both quiescent and star-forming galaxies within this redshift range, though we note the presence of weak evolution in the number densities of star-forming galaxies. We compare both VDFs with previous direct and inferred measurements at local and intermediate redshifts, with the caveat that previous measurements of the VDF for star-forming galaxies are poorly constrained at all epochs. We emphasize that this work is the first to directly push to low-stellar velocity dispersion ($\sigma_\star > 100$ km s$^{-1}$) and extend to star-forming galaxies. We are largely consistent with the high-sigma tail measured from BOSS, and we find that the VDF remains constant from the median redshift of LEGA-C, $z\sim0.8$, to the present day.

Cycling of carbon dioxide between the atmosphere and interior of rocky planets can stabilize global climate and enable planetary surface temperatures above freezing over geologic time. However, variations in global carbon budget and unstable feedback cycles between planetary sub-systems may destabilize the climate of rocky exoplanets toward regimes unknown in the Solar System. Here, we perform clear-sky atmospheric radiative transfer and surface weathering simulations to probe the stability of climate equilibria for rocky, ocean-bearing exoplanets at instellations relevant for planetary systems in the outer regions of the circumstellar habitable zone. Our simulations suggest that planets orbiting G- and F-type stars (but not M-type stars) may display bistability between an Earth-like climate state with efficient carbon sequestration and an alternative stable climate equilibrium where CO$_2$ condenses at the surface and forms a blanket of either clathrate hydrate or liquid CO$_2$. At increasing instellation and with ineffective weathering, the latter state oscillates between cool, surface CO$_2$-condensing and hot, non-condensing climates. CO$_2$ bistable climates may emerge early in planetary history and remain stable for billions of years. The carbon dioxide-condensing climates follow an opposite trend in $p$CO$_2$ versus instellation compared to the weathering-stabilized planet population, suggesting the possibility of observational discrimination between these distinct climate categories.

On September 18, 2022, an alert by ceCube indicated that a ~170TeV neutrino arrived in directional coincidence with the blazar TXS 0506+056. This event adds to two previous ones: a neutrino alert from its direction on September 22, 2017, and a 3sigma signature of a dozen neutrinos in 2014/2015. deBruijn 2020 showed that these two previous neutrino emission episodes could be due to a supermassive binary black hole (SMBBH) where jet precession close to final coalescence results in periodic emission. This model predicted a new emission episode consistent with the September 18, 2022 neutrino observation. Here, we show that the neutrino cadence of TXS 0506+056 is consistent with a SMBBH origin with mass ratios q<0.3 for a total black hole mass of M>3e8Msun. For the first time, we calculate the characteristic strain of the gravitational wave emission of the binary, and show that the merger could be detectable by LISA for black hole masses <5e8Msun if the mass ratios are in the range 0.1<q<0.3. We predict that there can be a neutrino flare existing in the still to be analyzed IceCube data peaking some time between 08/2019 and 01/2021 if a precessing jet is responsible for all three detected emission episodes. The next flare is expected to peak in the period 01/2023 to 08/2026. Further observation will make it possible to constrain the mass ratio as a function of the black hole mass more precisely and would open the window toward the preparation of the detection of SMBBH mergers.

Er et al. (2021) recently proposed a two-planet solution to account for eclipse timing variations (ETVs) observed from the sdB binary NY Virginis. We tested the proposed planetary system for orbit stability using both numerical simulations and chaotic behavior analysis. The best-fit orbits, as well as those with parameters varying by the published uncertainty range in each parameter, were unstable on a timescale much less than the presumed lifetime of the PCEB phase ($\sim$100 Myr). suggesting that the proposed circumbinary companions fail to provide a complete explanation for the observed ETVs.

We reconsider the dynamics of accretion flows onto magnetized central star. For dipolar magnetically aligned case, the centrifugal barrier is at $R_{cb} = (2/3)^{1/3} R_c = 0.87 R_c$, where $R_c= ( G M/\Omega^2)^{1/3}$ is the corotation radius. For oblique dipole direct accretion from the corotation radius $R_c$ is possible only for magnetic obliquity satisfying $\tan \theta_\mu \geq 1/( 2 \sqrt{3}) $ ($\theta_\mu \geq 16.1^\circ $). The accretion proceeds in a form of funnel flows - along two streams centered on the $\mu-\Omega$ plane, with azimuthal opening angle $ \cos (\Delta \phi) = { \cot^ 2 {\theta_\mu} }/{12} $. For the magnetosphere distorted by the diamagnetic disk, the centrifugal barrier can be at as small radius as $R_{cb}= 0.719 R_c$ for the fully confined dipole, extending out to $R_{cb} \sim R_c$ for the magnetically balanced case. Type-II X-ray bursts in accreting neutron stars may be mediated by the centrifugal barrier; this requires nearly aligned configuration. Centrifugally-barriered material trapped in the magnetosphere may lead to periodic obscuration (``dips'') in the light curve of the host star, e.g., as observed in accreting young stellar objects and X-ray binaries.

Massive stars evolve toward the catastrophic collapse of their innermost core, producing core-collapse supernova (SN) explosions as the end products. White dwarfs, formed through evolution of the less massive stars, also explode as thermonuclear SNe if certain conditions are met during the binary evolution. Inflating opportunities in transient observations now provide an abundance of data, with which we start addressing various unresolved problems in stellar evolution and SN explosion mechanisms. In this chapter, we overview the stellar evolution channels toward SNe, explosion mechanisms of different types, and explosive nucleosynthesis. We then summarize observational properties of SNe through which the natures of the progenitors and explosion mechanisms can be constrained.

We measure and compare the pattern speeds of vertical breathing, vertical bending, and spiral density waves in two isolated N-body+SPH simulations, using windowed Fourier transforms over 1 Gyr time intervals. We show that the pattern speeds of the breathing waves match those of the spirals but are different from those of the bending waves. We also observe matching pattern speeds between the bar and breathing waves. Our results not only strengthen the case that, throughout the disc, breathing motions are driven by spirals but indeed that the breathing motions are part and parcel of the spirals.

The metallicity distributions of globular cluster (GC) systems in galaxies are a critical test of any GC formation scenario. In this work, we investigate the predicted GC metallicity distributions of galaxies in the MOdelling Star cluster population Assembly In Cosmological Simulations within EAGLE (E-MOSAICS) simulation of a representative cosmological volume ($L = 34.4$ comoving Mpc). We find that the predicted GC metallicity distributions and median metallicities from the fiducial E-MOSAICS GC formation model agree well the observed distributions, except for galaxies with masses $M_\ast \sim 2 \times 10^{10}$ M$_\odot$, which contain an overabundance of metal-rich GCs. The predicted fraction of galaxies with bimodal GC metallicity distributions ($37 \pm 2$ per cent in total; $45 \pm 7$ per cent for $M_\ast > 10^{10.5}$ M$_\odot$) is in good agreement with observed fractions ($44^{+10}_{-9}$ per cent), as are the mean metallicities of the metal-poor and metal-rich peaks. We show that, for massive galaxies ($M_\ast > 10^{10}$ M$_\odot$), bimodal GC distributions primarily occur as a result of cluster disruption from initially-unimodal distributions, rather than as a result of cluster formation processes. Based on the distribution of field stars with GC-like abundances in the Milky Way, we suggest that the bimodal GC metallicity distribution of Milky Way GCs also occurred as a result of cluster disruption, rather than formation processes. We conclude that separate formation processes are not required to explain metal-poor and metal-rich GCs, and that GCs can be considered as the surviving analogues of young massive star clusters that are readily observed to form in the local Universe today.

A thermal component is suggested to be the physical composition of the ejecta of several bright gamma-ray bursts (GRBs). Such a thermal component is discovered in the time-integrated spectra of several short GRBs as well as long GRBs. In this work, we present a comprehensive analysis of ten very short GRBs detected by Fermi Gamma-Ray Burst Monitor to search for the thermal component. We found that both the resultant low-energy spectral index and the peak energy in each GRB imply a common hard spectral feature, which is in favor of the main classification of the short/hard versus long/soft dichotomy in the GRB duration. We also found moderate evidence for the detection of thermal component in eight GRBs. Although such a thermal component contributes a small proportion of the global prompt gamma-ray emission, the modified thermal-radiation mechanism could enhance the proportion significantly, such as in subphotospheric dissipation.

The dynamics of the innermost Galilean satellites (Io, Europa and Ganymede) is characterised by a chain of mean motion resonances, called Laplace resonance, and by a strong tidal dissipation that causes wide variations of their semi-major axes over large timescales. The precise history of energy dissipation in the Jovian system is not known, but several theories have been proposed. Tidal resonance locking states that big outer moons can also migrate fast. If this is the case for Callisto, then it should have crossed the 2:1 mean motion resonance with Ganymede in the past, affecting the motion of all four Galilean satellites. Therefore, we aim to determine whether a fast migration for Callisto is compatible with the current orbital configuration of the system. Due to the chaotic nature of the resonant crossing, different outcomes are possible. A small portion of our simulations shows that Callisto can cross the 2:1 resonance with Ganymede without being captured and preserving the Laplace resonance. However, in most cases, we found that Callisto is captured into resonance, despite its divergent migration. As Callisto continues to migrate fast outwards, the moons depart substantially from the exact 8:4:2:1 commensurability, while still maintaining the resonant chain. Callisto can eventually escape it by crossing a high-order mean motion resonance with Ganymede. Afterwards, the moons' system is able to relax to its current configuration for suitable dissipation parameters of the satellites. Therefore it is possible, although challenging, to build a self-consistent picture of the past history of the Galilean satellites for a fast migration of Callisto.

Mass distribution of black holes in low-mass X-ray binaries previously suggested the existence of a $ \sim 2-5M_{\odot} $ mass gap between the most massive neutron stars and the least massive black holes, while some recent evidence appears to support that this mass gap is being populated. Whether there is a mass gap or not can potentially shed light on the physics of supernova explosions that form neutron stars and black holes, although significant mass accretion of neutron stars including binary mergers may lead to the formation of mass-gap objects. In this review, I collect the compact objects that are probable black holes with masses being in the gap. Most of them are in binaries, their mass measurements are obviously subject to some uncertainties. Current observations are still unable to confidently infer an absence or presence of the mass gap. Ongoing and future surveys are expected to build the mass spectrum of black holes which can be used to constrain the process of their formation especially in binaries. I describe the theoretical predictions for the formation of black holes in various types of binaries, and present some prospects of searching for black holes via electromagnetic and gravitational wave observations.

HUXt is an open source numerical model of the solar wind written in Python. It is based on the solution of the 1D inviscid Burger's equation. This reduced-physics approach produces solar wind flow simulations that closely emulate the flow produced by 3-D magnetohydrodynamic solar wind models at a small fraction of the computational expense. While not intended as a replacement for 3-D MHD, the simplicity and computational efficiency of HUXt offers several key advantages that enable experiments and the use of techniques that would otherwise be cost prohibitive. For example, large ensembles can easily be run with modest computing resources, which are useful for exploring and quantifying the uncertainty in space weather predictions, as well as for the application of some data assimilation methods. We present the developments in the latest version of HUXt, v4.0, and discuss our plans for future developments and applications of the model. The three key developments in v4.0 are: a restructuring of the models solver to enable fully time-dependent boundary conditions, such that HUXt can in principle be initialised with in-situ observations from any of the fleet of heliospheric monitors; new functionality to trace streaklines through the HUXt flow solutions, which can be used to track features such as the Heliospheric Current Sheet; introduction of a small test-suite so that we can better ensure the reliability and reproducibility of HUXt simulations for all users across future versions. Other more minor developments are discussed in the article. Future applications of HUXt are discussed, including the development data assimilation schemes for assimilation of both remote sensing and in-situ plasma measures. We discuss the progress of transitioning HUXt into an operational model at the UK's Met Office Space Weather Operations Center as part of the UK governments SWIMMR programme.

Motivated by the necessity of a high-quality stray light control in the detection of the gravitational waves in space, the spot size of a flat top beam generated by the clipping of the Gaussian beam(GB) is studied. By adopting the mode expansion method (MEM) approach to simulating the beam, a slight variant of the definition of the mean square deviation (MSD) spot size for the MEM beam is proposed and this enables us to quickly estimate the spot size for arbitrary propagation distance. Given that the degree of clipping is dependent on the power ratio within the surface of an optical element, the power ratio within the MSD spot range is used as a measure of spot size. The definition is then validated in the cases of simple astigmatic Gaussian beam and nearly-Gaussian beam profiles. As a representative example, the MSD spot size for a top-hat beam in a science interferometer in the detection of gravitational waves in space is then simulated. As in traditional MSD spot size analysis, the spot size is divergent when diffraction is taken into account. A careful error analysis is carried out on the divergence and in the present context, it is argued that this error will have little effect on our estimation. Using the results of our study allows an optimal design of optical systems with top-hat or other types of non-Gaussian beams. Furthermore, it allows testing the interferometry of space-based gravitational wave detectors for beam clipping in optical simulations. The present work will serve as a useful guide in the future system design of the optical bench and the sizes of the optical components.

Temperature measurement is essential in prestellar cores for understanding the initial conditions prior to the star formation. Here, in this work, we study the ammonia lines (J,K=1,1 and 2,2) in the prestellar core L1517B with the Very Large Array Radio Telescope (VLA). Our analysis indicates that the core is close to round in shape with a constant internal kinetic temperature of ~ 9K, suggesting the core seems to be an isothermal sphere. We find that the excitation temperature increases gradually towards the centre of the core, whereas the centre velocity of the line is almost constant and close to the systematic velocity of the core. Our study also reveals that a constant level of turbulence persists in the core, which is subsonic in nature, and notice that the decrement of column density of NH3 from the centre of the core to the edge, with a peak value of 10^{14.95} cm ^{-2}. Moreover,o ur work demonstrates the capability of studying the internal structures of prestellar cores with interferometric telescope.

We report the results of observations of p-mode oscillations in the G0 subgiant star HD 35833 in both radial velocities and photometry with NEID and TESS, respectively. We achieve separate, robust detections of the oscillation signal with both instruments (radial velocity amplitude $A_{\rm RV}=1.11\pm0.09$ m s$^{-1}$, photometric amplitude $A_{\rm phot}=6.42\pm0.60$ ppm, frequency of maximum power $\nu_{\rm max} = 595.71\pm17.28$ $\mu$Hz, and mode spacing $\Delta \nu = 36.65\pm0.96$ $\mu$Hz) as well as a non-detection in a TESS sector concurrent with the NEID observations. These data shed light on our ability to mitigate the correlated noise impact of oscillations with radial velocities alone, and on the robustness of commonly used asteroseismic scaling relations. The NEID data are used to validate models for the attenuation of oscillation signals for exposure times $t<\nu_{\rm max}^{-1}$, and we compare our results to predictions from theoretical scaling relations and find that the observed amplitudes are weaker than expected by $>4\sigma$, hinting at gaps in the underlying physical models.

The NEID spectrograph on the WIYN 3.5-m telescope at Kitt Peak has completed its first full year of science operations and is reliably delivering sub-m/s precision radial velocity measurements. The NEID instrument control system uses the TIMS package (Bender et al. 2016), which is a client-server software system built around the twisted python software stack. During science observations, interaction with the NEID spectrograph is handled through a pair of graphical user interfaces (GUIs), written in PyQT, which wrap the underlying instrument control software and provide straightforward and reliable access to the instrument. Here, we detail the design of these interfaces and present an overview of their use for NEID operations. Observers can use the NEID GUIs to set the exposure time, signal-to-noise ratio (SNR) threshold, and other relevant parameters for observations, configure the calibration bench and observing mode, track or edit observation metadata, and monitor the current state of the instrument. These GUIs facilitate automatic spectrograph configuration and target ingestion from the nightly observing queue, which improves operational efficiency and consistency across epochs. By interfacing with the NEID exposure meter, the GUIs also allow observers to monitor the progress of individual exposures and trigger the shutter on user-defined SNR thresholds. In addition, inset plots of the instantaneous and cumulative exposure meter counts as each observation progresses allow for rapid diagnosis of changing observing conditions as well as guiding failure and other emergent issues.

As part of the GLOSTAR survey we have used the VLA in its B-configuration to observe the part of the Galactic plane between longitudes of 28d and 36d and latitudes from -1d to +1d at the C-band (4--8 GHz). To reduce the contamination of extended sources that are not well recovered by our coverage of the (u, v)-plane we discarded short baselines that are sensitive to emission on angular scales $<4''$. The resulting radio continuum images have an angular resolution of 1.0'', and sensitivity of $\sim60 \mu$Jy~beam$^{-1}$; making it the most sensitive radio survey covering a large area of the Galactic plane with this angular resolution. An automatic source extraction algorithm was used in combination with visual inspection to identify a total of 3325 radio sources. A total of 1457 radio sources are $\geq7\sigma$ and comprise our highly reliable catalog; 72 of these are grouped as 22 fragmented sources, e.g., multiple components of an extended and resolved source. To explore the nature of the catalogued radio sources we searched for counterparts at millimeter and infrared wavelengths. Our classification attempts resulted in 93 HII region candidates, 104 radio stars, 64 planetary nebulae, while most of the remaining radio sources are suggested to be extragalactic sources. We investigated the spectral indices ($\alpha$, $S_\nu\propto\nu^\alpha$) of radio sources classified as HII region candidates and found that many have negative values. This may imply that these radio sources represent young stellar objects that are members of the star clusters around the high mass stars that excite the HII regions, but not these HII regions themselves. By comparing the peak flux densities from the GLOSTAR and CORNISH surveys we have identified 49 variable radio sources, most of them with an unknown nature. Additionally, we provide the list of 1866 radio sources detected within 5 to 7$\sigma$ levels.

The DAMIC experiment employs large-area, thick charge-coupled devices (CCDs) to search for the interactions of low-mass dark matter particles in the galactic halo with silicon atoms in the CCD target. From 2017 to 2019, DAMIC collected data with a seven-CCD array (40-gram target) installed in the SNOLAB underground laboratory. We report dark-matter search results, including a conspicuous excess of events above the background model below 200 eV$_{\rm ee}$, whose origin remains unknown. We present details of the published spectral analysis, and update on the deployment of skipper CCDs to perform a more precise measurement by early 2023.

The performance of high-contrast imaging instruments is limited by wavefront errors, in particular by non-common path aberrations (NCPA). Focal-plane wavefront sensing (FPWFS) is appropriate to handle NCPA because it measures the aberration where it matters the most, i.e., at the science focal plane. Phase retrieval from focal-plane images results nonetheless in a sign ambiguity for even modes of the pupil-plane phase. The phase diversity methods currently used to solve the sign ambiguity tend to reduce the science duty cycle, i.e., the fraction of observing time dedicated to science. In this work, we explore how we can combine the phase diversity provided by a vortex coronagraph with modern deep learning techniques to perform efficient FPWFS without losing observing time. We apply the state-of-the-art convolutional neural network EfficientNet-B4 to infer phase aberrations from simulated focal-plane images. The two cases of scalar and vector vortex coronagraphs (SVC and VVC) are considered, respectively using a single post-coronagraphic PSF or two PSFs obtained by splitting the circular polarization states. The sign ambiguity is properly lifted in both cases even at low signal-to-noise ratios (S/N). Using either the SVC or the VVC, we reach very similar performance compared to using phase diversity with a defocused PSF, except for high levels of aberrations where the SVC slightly underperforms compared to the other approaches. The models finally show great robustness when trained on data with a wide range of wavefront errors and noise levels. The proposed FPWFS technique provides a 100% science duty cycle for instruments using a vortex coronagraph and does not require any additional hardware in the case of the SVC.

SMACS~J0723.3-7327 is the first galaxy cluster lens observed by JWST. Based on the ERO data from JWST, several groups have reported the results on strong lensing analysis and mass distribution of this cluster. However, limited by the angular coverage of the JWST data, the strong lensing models only cover the central region. X-ray analysis on the hot ICM is necessary to obtain a more complete constraint on the mass distribution in this very massive cluster. In this work, we aim to perform a comprehensive X-ray analysis of J0723 to obtain accurate ICM hydrostatic mass measurements, using the X-ray data from SRG/eROSITA and Chandra X-ray observatories. By comparing the hydrostatic mass profile with the strong lensing model, we aim to provide the most reliable constraint on the distribution of mass up to R500. Thanks to the eROSITA all-sky survey and Chandra data, which provide high S/N and high angular resolution respectively, we are able to constrain the ICM gas density profile and temperature profile with good accuracy both in the core and to the outskirts. With the density and temperature profiles, we compute the hydrostatic mass profile, which is then projected along the line of sight to compare with the mass distribution obtained from the recent strong lensing analysis based on JWST data. We also deproject the strong lensing mass distribution using the hydrostatic mass profile we obtained in this work. The X-ray results obtained from eROSITA and Chandra agree very well with each other. The hydrostatic mass profiles we measured in this work, both projected and deprojected, are in good agreement with recent strong lensing results based on JWST data, at all radii.

Previous studies found that stellar scattering by massive clumps can lead to the formation of exponential profiles in galaxy discs, but details on how a star is moved around have not been fully explained. We use a GADGET-2 simulation where an exponential profile forms from an initially Gaussian disc in about 4 Gyr for a low-mass galaxy like a dwarf irregular. We find that nearly all large angular momentum changes of stars are caused by star-clump encounters with the closest approach less than 0.5 kpc. During star-clump encounters, stars may increase their random motions, resulting in an increase in the average radial and vertical actions of the whole stellar population. The angular momentum change and the radial action change of an individual star are influenced by the direction from which the star approaches a clump. A star initially at a higher galactic radius relative to the scattering clump usually gets pulled inwards and loses its angular momentum during the encounter, and one at a lower radius tends to shift outwards and gains angular momentum. The increase in the radial action is the largest if a star encounters a clump from the azimuthal direction, and is the smallest from a radial approach. The angular momentum change due to encounters has an inward bias when the clump profile has a steep radial decline, and a shallow decline can make the bias outwards. The stellar profile evolution towards an exponential seems to occur regardless of the direction of the bias.

There is a very popular two-zone accretion disk model that the inner part of the non-advective Keplerian disk (Shakura-Sunyaev disk) can produce hot advection-dominated accretion flow, which can generate high energy power-law radiation and outflows/jets. However, we find that this simple model is inadequate to automatically explain many properties of the sources (such as hysteresis effect, counter-clockwise traversal in a hardness-intensity diagram, peculiar variabilities, and association/non-association of jets in a black hole $X-$ray binary) without considering additional assumptions. We also find some theoretical issues in this model, such as understanding of variation of transition region and formation of an outer disk, which has only Keplerian distribution. Based on the recent theoretical studies on advective disk structures, as well as, many observational behaviors of the accreting black holes, we conclude that there should be a third component (TC) of accretion flow parallel to the two-zone disk model, which can naturally explain all above mentioned issues. Interestingly, this modified model also provides a new scenario for the jet generation and evolution with the TC flow during high energy states, which can make the jet close to the axis. We also find out an expression of jet kinetic power.

It was suggested that the prominent feature of the optical Fe II emission has a connection with the accretion process in active galactic nuclei (AGN). For a large sample of 4037 quasars ($z < 0.8$) with measured $\rm H\beta$ line dispersion ($\sigma_{\rm H\beta}$) selected from the Sloan Digital Sky Survey (SDSS) and 120 compiled reverberation-mapped (RM) AGN, we use $\sigma_{\rm H\beta}$ and the extended $R_{\rm BLR}-L_{\rm 5100}$ relation to calculate supermassive black holes masses ($M_{\rm BH}$) from the single-epoch spectra for the SDSS subsample, and $\sigma_{\rm H\beta}$ from the mean spectra for the RM subsample. We find a strong correlation between the relative optical Fe II strength $R_{\rm Fe}$ and $\dot{\mathscr{M}}$ for the SDSS subsample with the Spearman correlation coefficient $r_s$ of $0.727$, which is consistent with that derived from the mean spectra for the RM subsample. The magnitude of velocity shift of the optical Fe II emission has a strong anticorrelation with $\dot{\mathscr{M}}$, whenever there is inflow or outflow. These strong correlations show that the optical Fe II emission has an intimate connection with the accretion process. Assuming that the difference of $M_{\rm BH}$ is due to the variable virial factor $f$ for adopting $ \rm FWHM_{H\beta}$ as the velocity tracer, we find that there is a relation between $f$ and $\rm FWHM_{H\beta}$, $\log f=-(0.41\pm 0.002) \rm \log FWHM_{\rm H\beta}+(1.719\pm 0.009)$ for the single-epoch spectrum. The relation between $\log f$ and $\sigma_{\rm H\beta}$ is not too strong, suggesting that $\sigma_{\rm H\beta}$ does not seem to depend much on the broad-line region inclination and a constant $\sigma$-based $f$ is suitable for $\sigma_{\rm H\beta}$ as the velocity tracer.

We develop the 3-dimensional general relativistic radiative transfer code: CARTOON (Calculation code of Authentic Radiative Transfer based On phOton Number conservation in curved space-time) which is improved from the 2-dimensional code: ARTIST developed by Takahashi & Umemura (2017). In CARTOON, the frequency-integrated general relativistic radiative transfer equation is solved in a photon number-conserving manner, and the isotropic and coherent scattering in the zero angular momentum observers (ZAMO) frame and the fluid rest frame is incorporated. By calculating the average energy of photons, energy conservation of the radiation is also guaranteed. With the test calculations in 2-dimensional and 3-dimensional space, we have demonstrated that the wavefront propagation in black hole space-time can be correctly solved in CARTOON conserving photon numbers. The position of the wavefront coincides with the analytical solution and the number of photons remains constant until the wavefront reaches the event horizon. We also solve the radiative transfer equation on the geodesic reaching the observer's screen. The time variation of the intensity map on the observer's screen can be simultaneously and consistently calculated with the time variation of the radiation field around the black hole. In addition, the black hole shadow can be reproduced in moderately optically thin situations.

A variety of new physical processes have proven to play an important role in orbital decay of a satellite galaxy embedded inside a dark matter halo but this is not fully understood. Our goal is to assess if the orbital history of a satellite remains unchanged during a concurrent sinking. For this purpose we analyze the impact that the internal structure of the satellites and their spatial distribution inside the host halo may have on the concurrent sinking process due to both mass loss and the combined effect of self-friction, which have not been studied before for concurrent sinking. We set up a set of N-body simulations that include multiple satellites, sinking simultaneously in a host halo and we compare them with models including a single satellite. The main result of our work is that the satellite's accretion history differs from the classical isolated view when we consider the collective effects. The accretion history of each satellite strongly depends on the initial configuration, the number of satellites in the halo at the time of infall and the internal properties of each satellite. We observe that compact satellites in a flat configuration fall slower than extended satellites that have lost mass, showing a non-reported behavior of self-friction. We find that such effects are maximized when satellites are located in a flat configuration. We show that in a flat configuration similar to the Vast Polar Structure, deviations in the apocenters can be of about 30% with respect to the isolated case, and up to 50% on the eccentricities. We conclude that ignoring the collective effects produced by the concurrent sinking of satellite galaxies may lead to large errors in the determination of the merger progenitors properties, making it considerably more challenging to trace back the accretion event. Timing constrains on host density profile may be modified by the effects discussed here.

We investigate the potential of using a sample of very high-redshift ($2\lesssim z \lesssim6$) (VHZ) Type Ia supernovae (SNe~Ia) attainable by the James Webb Space Telescope (JWST) on constraining cosmological parameters. At such high redshifts, the age of the universe is young enough that the VHZ SNIa sample comprises the very first SNe~Ia of the universe, with progenitors among the very first generation of low mass stars that the universe has made. We show that the VHZ SNe~Ia can be used to disentangle systematic effects due to the luminosity distance evolution with redshifts intrinsic to SNIa standardization. Assuming that the systematic evolution can be described by a linear or logarithmic formula, we found that the coefficients of this dependence can be determined accurately and decoupled from cosmological models. Systematic evolution as large as 0.15 mag and 0.45 mag out to $z=5$ can be robustly separated from popular cosmological models for the linear and logarithmic evolution, respectively. The VHZ SNe~Ia will lay the foundation for quantifying the systematic redshift evolution of SNIa luminosity distance scales. When combined with SNIa surveys at comparatively lower redshifts, the VHZ SNe~Ia allow for a precise measurement of the history of the expansion of the universe from $z\sim 0$ to the epoch approaching reionization.

LHAASO J2108+5157 is one of the few known unidentified Ultra-High-Energy (UHE) gamma-ray sources with no Very-High-Energy (VHE) counterpart, recently discovered by the LHAASO collaboration. We observed LHAASO J2108+5157 in the X-ray band with XMM-Newton in 2021 for a total of 3.8 hours and at TeV energies with the Large-Sized Telescope prototype (LST-1), yielding 49 hours of good quality data. In addition, we analyzed 12 years of Fermi-LAT data, to better constrain emission of its High-Energy (HE) counterpart 4FGL J2108.0+5155. We found an excess (3.7 sigma) in the LST-1 data at energies E > 3 TeV. Further analysis in the whole LST-1 energy range assuming a point-like source, resulted in a hint (2.2 sigma) of hard emission which can be described with a single power law with photon index Gamma = 1.6 +- 0.2 between 0.3 - 100 TeV. We did not find any significant extended emission which could be related to a Supernova Remnant (SNR) or Pulsar Wind Nebula (PWN) in the XMM-Newton data, which puts strong constraints on possible synchrotron emission of relativistic electrons. The LST-1 and LHAASO observations can be explained as inverse Compton dominated leptonic emission of relativistic electrons with cutoff energy of 100+70-30 TeV. The low magnetic field in the source imposed by the X-ray upper limits on synchrotron emission is compatible with a hypothesis of a TeV halo. Furthermore, the spectral properties of the HE counterpart are consistent with a hypothesis of Geminga-like pulsar, which would be able to power the VHE-UHE emission. LST-1 and Fermi-LAT upper limits impose strong constraints on hadronic scenario of pi-0 decay dominated emission from accelerated protons interacting with nearby molecular clouds, requiring hard spectral index, which is incompatible with the standard diffusive acceleration scenario.

Recent radio-frequency probes, with the ATCA and ASKAP telescopes, have proven themselves to be at the forefront of placing indirect limits on the properties of dark matter. The latter being able to substantially exceed the constraining power of Fermi-LAT data. However, these observations were based only on dwarf galaxies, where magnetic field uncertainties are large. Here we re-examine the case for galaxy clusters, often ignored due to substantial diffuse radio backgrounds, by considering the extrapolation of known cluster surface brightness profiles down to scales observable with MeerKAT. Despite large baryonic backgrounds, we find that clusters can be competitive with dwarf galaxies. Extrapolated Coma data being able to rule out WIMPs of mass $< 700$ GeV annihilating via $b$-quarks. This is while having lesser uncertainties surrounding the magnetic field and diffusive environment. Such compelling results are possible due to a clash between the inner shape of the dark matter halo and the flat inner profile of radio halos which is most pronounced for NFW-like Einasto profiles, the presence of which having some supporting evidence in the literature.

BL Lacertae, the prototype of the BL Lacertae (BL Lac) category of blazars, underwent a giant $\gamma-$ray flare in April 2021. The Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope (hereafter Fermi-LAT) observed a peak $\gamma-$ray (0.1$-$500 GeV) flux of $\sim$2 $\times$ 10$^{-5}$ photons cm$^{-2}$ s$^{-1}$ within a single orbit on 2021 April 27, which is historically the brightest $\gamma-$ray flux ever detected from the source. Here, we report, for the first time, the detection of significant minute-timescale GeV $\gamma-$ray flux variability in the BL Lac subclass of blazars by the Fermi-LAT. We resolved the source variability down to 2-min binned timescales with a flux halving time of $\sim$1 minute, which is the shortest GeV variability timescale ever observed from blazars. The detected variability timescale is much shorter than the light-crossing time ($\sim 14$ minutes) across the central black hole of BL Lac indicating a very compact $\gamma-$ray emission site within the outflowing jet. Such a compact emitting region requires the bulk Lorentz factor of the jet to be larger than 16 so that the jet power is not super Eddington. We found a minimum Doppler factor $\delta_{min}$ of 15 using the $\delta$ function approximation for the $\gamma\gamma$ opacity constraint. For a conical jet geometry, considering $\Gamma = \delta_{min}$, the observed short variability timescale suggests the very compact emission region to lie at a distance of about 8.62 $\times$ 10$^{14}$ cm from the central engine of BL Lac.

The cocoon is an inevitable product of a jet propagating through ambient matter, and takes a fair fraction of the jet energy. In short gamma-ray bursts, the ambient matter is the ejecta, from the merger of neutron stars, expanding with a high velocity $\sim 0.2 c$, in contrast to the static stellar envelope in collapsars. Using 2D relativistic hydrodynamic simulations with $r^{-2}$ density profile, we find that the expansion makes a big difference; only 0.5--5\% of the cocoon mass escapes from (faster than) the ejecta, with an opening angle $20^{\circ}$--$30^{\circ}$, while it is $\sim 100\%$ and spherical in collapsars. We also analytically obtain the shares of mass and energies for the escaped and trapped cocoons. Considering the small mass range of the escaped cocoon, and because the trapped cocoon is concealed by the ejecta and the escaped cocoon, we conclude that it is unlikely that the cocoon emission was observed as a counterpart to the gravitational wave event GW170817.

The Solar MAgnetic Connection HAUS tool (Solar-MACH) is an open-source tool completely written in Python that derives and visualizes the spatial configuration and solar magnetic connection of different observers (i.e., spacecraft or planets) in the heliosphere at different times. For doing this, the magnetic connection in the interplanetary space is obtained by the classic Parker Heliospheric Magnetic Field (HMF). In close vicinity of the Sun, a Potential Field Source Surface (PFSS) model can be applied to connect the HMF to the solar photosphere. Solar-MACH is especially aimed at providing publication-ready figures for the analyses of Solar Energetic Particle events (SEPs) or solar transients such as Coronal Mass Ejections (CMEs). It is provided as an installable Python package (listed on PyPI and conda-forge), but also as a web tool at solar-mach.github.io that completely runs in any web browser and requires neither Python knowledge nor installation. The development of Solar-MACH is open to everyone and takes place on GitHub, where the source code is publicly available under the BSD 3-Clause License. Established Python libraries like sunpy and pfsspy are utilized to obtain functionalities when possible. In this article, the Python code of Solar-MACH is explained, and its functionality is demonstrated using real science examples. In addition, we introduce the overarching SERPENTINE project, the umbrella under which the recent development took place.

A diagnosis of the Ar densities measured by the Neutral Gas and Ion Mass Spectrometer aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) and the temperatures derived from these densities shows that solar activity, solar insolation, and the lower atmospheric dust are the dominant forcings of the Martian thermosphere. A methodology, based on multiple linear regression analysis, is developed to quantify the contributions of the dominant forcings to the densities and temperatures. The results of the present study show that a 100 sfu (solar flux units) change in the solar activity results in approx. 136 K corresponding change in the thermospheric temperatures. The solar insolation constrains the seasonal, latitudinal, and diurnal variations to be interdependent. Diurnal variation dominates the solar insolation variability, followed by the latitudinal and seasonal variations. Both the global and regional dust storms lead to considerable enhancements in the densities and temperatures of the Martian thermosphere. Using past data of the solar fluxes and the dust optical depths, the state of the Martian thermosphere is extrapolated back to Martian year (MY) 24. While the global dust storms of MY 25, MY 28 and MY 34 raise the thermospheric temperatures by approx. 22-38 K, the regional dust storm of MY 34 leads to approx. 15 K warming. Dust driven thermospheric temperatures alone can enhance the hydrogen escape fluxes by 1.67-2.14 times compared to those without the dust. Dusts effects are relatively significant for global dust storms that occur in solar minimum compared to those that occur in solar maximum.

Exa-scale simulations are on the horizon but almost no new design for the output has been proposed in recent years. In simulations using individual time steps, the traditional snapshots are over resolving particles/cells with large time steps and are under resolving the particles/cells with short time steps. Therefore, they are unable to follow fast events and use efficiently the storage space. The Continuous Simulation Data Stream (CSDS) is designed to decrease this space while providing an accurate state of the simulation at any time. It takes advantage of the individual time step to ensure the same relative accuracy for all the particles. The outputs consist of a single file representing the full evolution of the simulation. Within this file, the particles are written independently and at their own frequency. Through the interpolation of the records, the state of the simulation can be recovered at any point in time. In this paper, we show that the CSDS can reduce the storage space by 2.76x for the same accuracy than snapshots or increase the accuracy by 67.8x for the same storage space whilst retaining an acceptable reading speed for analysis. By using interpolation between records, the CSDS provides the state of the simulation, with a high accuracy, at any time. This should largely improve the analysis of fast events such as supernovae and simplify the construction of light-cone outputs.

We analyse spectra of 26 early-type stars, with suspected binarity, using a binary spectral model adapted for high-resolution FEROS spectra. We confirm seven SB2 candidates (AE Pic, $\epsilon$ Vol, HD 20784, HD 208433, HD 43519, HD 56024, CD-73~375A) and derive mass ratios and spectroscopic parameters for them. We find good agreement with theoretical models. For slightly evolved system HD 20784 we made the first estimation of the fundamental parameters and age $\log{t}=8.5$ yr.

The evolutionary status of 24 post-AGB stars is presented based on Gaia DR3 data. All 24 stars have parallaxes accurate to better than 3 X sigma and have RUWE values less than 1.4. Based on the Gaia DR3 distances the absolute luminosities are derived. For 14 of the stars, the luminosities confirm their post-AGB evolutionary stage. However, V1027 Cyg, which was previously classified as a post-AGB star, is found to have a higher luminosity; thus it may be an evolved, massive, pulsating semi-regular variable star of type G7Ia. For 9 of the stars, the luminosities are lower than 1000 L (sun), indicating that some are post-RGB stars and some are post-HB stars.This paper was completed more than four months ago but there was delay in getting it published.

The pairwise collisional growth of dust aggregates consisting submicron-sized grains is the first step of the planet formation, and understanding the collisional behavior of dust aggregates is therefore essential. It is known that the main energy dissipation mechanisms are the tangential frictions between particles in contact, namely, rolling, sliding, and twisting. However, there is a large uncertainty for the strength of rolling friction, and the dependence of the collisional growth condition on the strength of rolling friction was poorly understood. Here we performed numerical simulations of collisions between two equal-mass porous aggregates with various collision velocities and impact parameters, and we also changed the strength of rolling friction systematically. We found that the threshold of the collision velocity for the fragmentation of dust aggregates is nearly independent of the strength of rolling friction. This is because the total amount of the energy dissipation by the tangential frictions is nearly constant even though the strength of rolling friction is varied.

We examine the migration of luminous low-mass cores in laminar protoplanetary discs where accretion occurs mainly because of disc winds and where the planet luminosity is generated by pebble accretion. Using 2D hydrodynamical simulations, we determine the eccentricities induced by thermal forces as a function of gas and pebble accretion rates, and also evaluate the importance of the torque exerted by the solid component relative to the gas torque. For a gas accretion rate $\dot M= 2\times 10^{-8}$ $M_\odot/$yr and pebble flux $\dot M_{peb}=170$ $M_\oplus$/Myr, we find that embryo eccentricities attain values comparable to the disc aspect ratio. The planet radial excursion in the disc, however, causes the torque exerted by inflowing pebbles to cancel on average and migration to transition from outward to inward. This is found to arise because the magnitude of thermal torques decreases exponentially with increasing eccentricity, and we provide a fitting formula for the thermal torque attenuation as a function of eccentricity. As the disc evolves, the accretion luminosity becomes at some point too small to make the core eccentricity grow such that the solid component can exert a non-zero torque on the planet. This torque is positive and for gas accretion rates $\dot M \lesssim 5\times 10^{-9}$ $M_\odot/$yr and pebble fluxes $\dot M_{peb} \lesssim 120$ $M_\oplus/$Myr, it is found to overcome the gas torque exerted on cores with mass $m_p\lesssim$ $1M_\oplus$, resulting in outward migration.

We extend the prediction of vibrational spectra to large sized polycyclic aromatic hydrocarbon (PAH) molecules comprising up to \sim 1500 carbon atoms by evaluating the efficiency of several computational chemistry methodologies. We employ classical mechanics methods (Amber and Gaff) with improved atomic point charges, semi-empirical (PM3, and density functional tight binding), and density functional theory (B3LYP) and conduct global optimizations and frequency calculations in order to investigate the impact of PAH size on the vibrational band positions. We primarily focus on the following mid-infrared emission bands 3.3, 6.2, 7.7, 8.6, 11.3, 12.7, and 17.0 microns. We developed a general Frequency Scaling Function (FSF) to shift the bands and to provide a systematic comparison versus the three methods for each PAH. We first validate this procedure on IR scaled spectra from the NASA Ames PAH Database, and extend it to new large PAHs. We show that when the FSF is applied to the Amber and Gaff IR spectra, an agreement between the normal mode peak positions with those inferred from the B3LYP/4-31G model chemistry is achieved. As calculations become time intensive for large sized molecules Nc > 450, this proposed methodology has advantages. The FSF has enabled extending the investigations to large PAHs where we clearly see the emergence of the 17.0 microns feature, and the weakening of the 3.3 microns one. We finally investigate the trends in the 3.3 microns 17.0 microns PAH band ratio as a function of PAH size and its response following the exposure to fields of varying radiation intensities.

Chemical and mineral compositions of asteroids reflect the formation and history of our Solar System. This knowledge is also important for planetary defence and in-space resource utilisation. We aim to develop a fast and robust neural-network-based method for deriving the mineral modal and chemical compositions of silicate materials from their visible and near-infrared spectra. The method should be able to process raw spectra without significant pre-processing. We designed a convolutional neural network with two hidden layers for the analysis of the spectra, and trained it using labelled reflectance spectra. For the training, we used a dataset that consisted of reflectance spectra of real silicate samples stored in the RELAB and C-Tape databases, namely olivine, orthopyroxene, clinopyroxene, their mixtures, and olivine-pyroxene-rich meteorites. We used the model on two datasets. First, we evaluated the model reliability on a test dataset where we compared the model classification with known compositional reference values. The individual classification results are mostly within 10 percentage-point intervals around the correct values. Second, we classified the reflectance spectra of S-complex (Q-type and V-type, also including A-type) asteroids with known Bus-DeMeo taxonomy classes. The predicted mineral chemical composition of S-type and Q-type asteroids agree with the chemical composition of ordinary chondrites. The modal abundances of V-type and A-type asteroids show a dominant contribution of orthopyroxene and olivine, respectively. Additionally, our predictions of the mineral modal composition of S-type and Q-type asteroids show an apparent depletion of olivine related to the attenuation of its diagnostic absorptions with space weathering. This trend is consistent with previous results of the slower pyroxene response to space weathering relative to olivine.

We report the discovery of NGTS-21b, a massive hot Jupiter orbiting a low-mass star as part of the Next Generation Transit Survey (NGTS). The planet has a mass and radius of $2.36 \pm 0.21$ M$_{\rm J}$, and $1.33 \pm 0.03$ R$_{\rm J}$, and an orbital period of 1.543 days. The host is a K3V ($T_{\rm eff}=4660 \pm 41$, K) metal-poor (${\rm [Fe/H]}=-0.26 \pm 0.07$, dex) dwarf star with a mass and radius of $0.72 \pm 0.04$, M$_{\odot}$,and $0.86 \pm 0.04$, R$_{\odot}$. Its age and rotation period of $10.02^{+3.29}_{-7.30}$, Gyr and $17.88 \pm 0.08$, d respectively, are in accordance with the observed moderately low stellar activity level. When comparing NGTS-21b with currently known transiting hot Jupiters with similar equilibrium temperatures, it is found to have one of the largest measured radii despite its large mass. Inflation-free planetary structure models suggest the planet's atmosphere is inflated by $\sim21\%$, while inflationary models predict a radius consistent with observations, thus pointing to stellar irradiation as the probable origin of NGTS-21b's radius inflation. Additionally, NGTS-21b's bulk density ($1.25 \pm 0.15$, g/cm$^3$) is also amongst the largest within the population of metal-poor giant hosts ([Fe/H] < 0.0), helping to reveal a falling upper boundary in metallicity-planet density parameter space that is in concordance with core accretion formation models. The discovery of rare planetary systems such as NGTS-21 greatly contributes towards better constraints being placed on the formation and evolution mechanisms of massive planets orbiting low-mass stars.

Magnetic fields ($\textbf{B}$) are an important factor that controls the star formation process. The leading method to observe $\textbf{B}$ is using polarized thermal emission from dust grains aligned with $\textbf{B}$. However, in dense environments such as protostellar cores, dust grains may have inefficient alignment due to strong gas randomizations, so that using dust polarization to trace $\textbf{B}$ is uncertain. Hoang $\&$ Lazarian (2016) demonstrated that the grain alignment by RAdiative Torques is enhanced if dust grains contain embedded iron inclusions. Here we extend POLARIS code to study the effect of iron inclusions on grain alignment and thermal dust polarization toward a protostellar core, assuming uniform magnetic fields. We found that paramagnetic grains produce a low polarization degree of $p \sim 1\%$ in the envelope and negligible $p \ll 1\%$ in the central region due to the loss of grain alignment. In contrast, grains with a high level of iron inclusions can have perfect alignment and produce high $p \sim 40\%$ in the envelope and low $p \leq 10\%$ in the central region. Grains with a moderate level of iron inclusions induce the polarization flipping from $\textbf{P}$ $\parallel$ $\textbf{B}$ at millimeter to $\textbf{P}$ $\perp$ $\textbf{B}$ at submillimeter due to the change in the internal alignment caused by slow internal relaxation. The weak alignment of very large grains of $a \geq 10\mu m$ reduces the polarization by dichroic extinction at submillimeter wavelengths. We found a positive correlation between p and the level of iron inclusions, which opens a new window to constrain the abundance of irons locked in dust through dust polarimetry.

This work provides a concrete implementation of E. Fermi's model of particle acceleration in magnetohydrodynamic (MHD) turbulence, connecting the rate of energization to the gradients of the velocity of magnetic field lines, which it characterizes within a multifractal picture of turbulence intermittency. It then derives a transport equation in momentum space for the distribution function. This description is shown to be substantiated by a large-scale numerical simulation of strong MHD turbulence. The present, general framework can be used to model particle acceleration in a variety of environments.

Nulling interferometry is one of the most promising technologies for imaging exoplanets within stellar habitable zones. The use of photonics for carrying out nulling interferometry enables the contrast and separation required for exoplanet detection. So far, two key issues limiting current-generation photonic nullers have been identified: phase variations and chromaticity within the beam combiner. The use of tricouplers addresses both limitations, delivering a broadband, achromatic null together with phase measurements for fringe tracking. Here, we present a derivation of the transfer matrix of the tricoupler, including its chromatic behaviour, and our 3D design of a fully symmetric tricoupler, built upon a previous design proposed for the GLINT instrument. It enables a broadband null with symmetric, baseline-phase-dependent splitting into a pair of bright channels when inputs are in anti-phase. Within some design trade space, either the science signal or the fringe tracking ability can be prioritised. We also present a tapered-waveguide $180^\circ$-phase shifter with a phase variation of $0.6^\circ$ in the $1.4-1.7~\mu$m band, producing a near-achromatic differential phase between beams{ for optimal operation of the tricoupler nulling stage}. Both devices can be integrated to deliver a deep, broadband null together with a real-time fringe phase metrology signal.

Short-lived (100s or less), sub-arcsec to a couple of arcsec size features of enhanced brightenings in the narrowband images at the $\mathrm{H_{2V}}$ and $\mathrm{K_{2V}}$ positions of the Ca II H and K lines in the quiet Sun are known as bright grains. With simultaneous observations of a quiet Sun internetwork region in the Fe I 6173 {\AA}, Ca II 8542 {AA}, and Ca II K lines acquired by the CRisp Imaging Spectro-Polarimeter and the CHROMospheric Imaging Spectrometer instruments on the Swedish 1-m Solar Telescope, we performed multi-line non-local thermodynamic equilibrium inversions using the STockholm inversion Code to infer the time-varying stratified atmosphere's physical properties such as the temperature, line-of-sight (LOS) velocity, and microturbulence. The Ca II K profiles of bright grains show enhancement in the $\mathrm{K_{2V}}$ peak intensities with absence of the $\mathrm{K_{2R}}$ features. At the time of maximum enhancement in the $\mathrm{K_{2V}}$ peak intensities, we found average enhancements in temperature at lower chromospheric layers (at $\log\tau_{500}$ $\simeq$ $-$4.2) of about 1.1 kK with maximum enhancement of about 4.5 kK. These temperature enhancements are colocated with upflows, as strong as $-$6 $\mathrm{km\;s^{-1}}$, in the direction of the LOS. The LOS velocities at upper chromospheric layers at $\log\tau_{500}$ < $-$4.2 show consistent downflows greater than $+$8 $\mathrm{km\;s^{-1}}$. The retrieved value of microturbulence in the atmosphere of bright grains is negligible at chromospheric layers. The study provides observational evidence to support the interpretation that the bright grains observed in narrowband images at the $\mathrm{H_{2V}}$ and $\mathrm{K_{2V}}$ positions of the Ca II H and K lines are manifestations of upward propagating acoustic shocks against a background of downflowing atmospheres.

Local non-Gaussianities in the initial conditions of the Universe, parameterized by $f_{\rm NL}$, induce a scale-dependence in the large-scale bias of halos in the late Universe. This effect is a promising path to constrain multi-field inflation theories that predict non-zero $f_{\rm NL}$. While most existing constraints from the halo bias involve auto-correlations of the galaxy distribution, cross-correlations with probes of the matter density provide an alternative channel with fewer systematics. We present the strongest large-scale structure constraint on local primordial non-Gaussianity that uses cross-correlations alone. We use the cosmic infrared background (CIB) consisting of dusty galaxies as a halo tracer and cosmic microwave background (CMB) lensing as a probe of the underlying matter distribution, both from \textit{Planck} data. Milky Way dust is a key challenge in using the large-scale modes of the CIB. Importantly, the cross-correlation of the CIB with CMB lensing is far less affected by Galactic dust compared to the CIB auto-spectrum, which picks up an additive bias from Galactic dust. We find no evidence for primordial non-Gaussianity and find $-87<f_{\rm NL}<19$ with a Gaussian $\sigma(f_{\rm NL})\approx 41$, assuming universality of the halo mass function. We find that future CMB lensing data from Simons Observatory and CMB-S4 could achieve $\sigma(f_{\rm NL})$ of 23 and 20 respectively. The constraining power of such an analysis is limited by current Galactic dust cleaning techniques, requiring us to use a minimum multipole of $\ell=70$. If this challenge is overcome with improved analysis techniques or external data, constraints as tight as $\sigma(f_{\rm NL})=4$ can be achieved through the cross-correlation technique. More optimistically, constraints better than $\sigma(f_{\rm NL})=2$ could be achieved if the CIB auto-spectrum is dust-free down to the largest scales.

We present an in-depth analysis of gas morphologies for a sample of 25 Milky Way-like galaxies from the Illustris TNG50 simulation. We constrain the morphology of cold, warm, hot gas, and gas particles as a whole using a Local Shell Iterative Method (LSIM) and explore its observational implications by computing the hard-to-soft X-ray ratio, which ranges between $10^{-3}$-$10^{-2}$ in the inner $\sim 50 \rm kpc$ of the distribution and $10^{-5}$-$10^{-4}$ at the outer portion of the hot gas distribution. We group galaxies into three main categories: simple, stretched, and twisted. These categories are based on the radial reorientation of the principal axes of the reduced inertia tensor. We find that the vast majority ($76\%$) of galaxies in our sample exhibit twisting patterns in their radial profiles. Additionally, we present detailed comparisons between 1) the gaseous distributions belonging to individual temperature regimes, 2) the cold gas distributions and stellar distributions, and 3) the gaseous distributions and dark matter (DM) halos. We find a strong correlation between the morphological properties of the cold gas and stellar distributions. Furthermore, we find a correlation between gaseous distributions with DM halo which increases with gas temperature, implying that we may use the gaseous morphology as a tracer to probe the DM morphology. Finally, we show gaseous distributions exhibit significantly more prolate morphologies than the stellar distributions and DM halos, which we hypothesize may be due to stellar and AGN feedback.

A potential crewed mission to Mars would require us to solve a number of problems, including how to protect astronauts against the devastating effects of energetic charged particles from Solar and Galactic sources. The radiation environment on Mars is of particular interest, since maintaining optimal absorbed doses by astronauts is crucial to their survival. Here, we give an overview of the conditions on Mars, as determined by theoretical models and in-situ measurements, and present the main proposed strategies to mitigate radiation exposure while on Mars. Specifically, we focus on the passive shielding technique. Several widely used materials, along with some innovative ones and combinations of those, are studied for their behavior against Solar Energetic Particle Events and Galactic Cosmic Rays in the Martian environment. For that purpose, we implement the GEANT4 package, a Monte-Carlo numerical model developed by CERN, which is specifically applied to simulate interactions of radiation with matter. A description of our model will be given, followed by outputs of the numerical model. We conclude that hydrogen-rich materials act as better attenuators, as expected, but other materials can be helpful against cosmic rays too.

We embed linear and nonlinear parametrisations of beyond standard cosmological physics in the halo model reaction framework, providing a model-independent prescription for the nonlinear matter power spectrum. As an application, we focus on Horndeski theories, using the Effective Field Theory of Dark Energy (EFTofDE) to parameterise linear and quasi-nonlinear perturbations. In the nonlinear regime we investigate both a nonlinear parameterised-post Friedmann (nPPF) approach as well as a physically motivated and approximate phenomenological model based on the error function (Erf). We compare the parameterised approaches' predictions of the nonlinear matter power spectrum to the exact solutions in two well studied modified gravity models, finding sub-percent agreement using the Erf model at $z\leq1$ and $k\leq 5~h/{\rm Mpc}$. This suggests only an additional 3 free constants, above the background and linear theory parameters, are sufficient to model nonlinear, non-standard cosmology in the matter power spectrum at scales down to $k \leq 3h~/{\rm Mpc}$ within $2\%$ accuracy. We implement the parametrisations into ver.2.0 of the ReACT code.

We present a detailed analysis of the protostellar outflow activity in the massive star-forming region NGC 3324, as revealed by new Early Release Observations (ERO) from the James Webb Space Telescope (JWST). Emission from numerous outflows is revealed in narrow-band images of hydrogen Paschen-$\alpha$ (Pa-$\alpha$) and molecular hydrogen. In particular, we report the discovery of 24 previously unknown outflows based on their H$_2$ emission. We find three candidate driving sources for these H$_2$ flows in published catalogs of young stellar objects (YSOs) and we identify 15 IR point sources in the new JWST images as potential driving protostars. We also identify several Herbig-Haro (HH) objects in Pa-$\alpha$ images from JWST; most are confirmed as jets based on their proper motions measured in a comparison with previous Hubble Space Telescope (HST) H$\alpha$ images. This confirmed all previous HST-identified HH jets and candidate jets, and revealed 7 new HH objects. The unprecedented capabilities of JWST allow the direct comparison of atomic and molecular outflow components at comparable angular resolution. Future observations will allow quantitative analysis of the excitation, mass-loss rates, and velocities of these new flows. As a relatively modest region of massive star formation (larger than Orion but smaller than starburst clusters), NGC 3324 offers a preview of what star formation studies with JWST may provide.

We examine the temperature structure of static coronal active region loops in regimes where thermal conductive transport is driven by Coulomb collisions, by turbulent scattering, or by a combination of the two. (In the last case collisional scattering dominates the heat transport at lower levels in the loop where temperatures are low and densities are high, while turbulent scattering dominates the heat transport at higher temperatures/lower densities.) Temperature profiles and their corresponding differential emission measure distributions are calculated and compared to observations, and earlier scaling laws relating the loop apex temperature and volumetric heating rate to the loop length and pressure are revisited. Results reveal very substantial changes, compared to the wholly collision-dominated case, to both the loop scaling laws and the temperature/density profiles along the loop. They also show that the well-known excess of differential emission measure at relatively low temperatures in the loop may be a consequence of for by the flatter temperature gradients (and so increased amount of material within a specified temperature range) that results from the predominance of turbulent scattering in the upper regions of the loop.

We present results on the morphological and structural evolution of a total of 4265 galaxies observed with JWST at $1.5 < z < 8$ in the JWST CEERS observations that overlap with the CANDELS EGS field. This is the biggest visually classified sample observed with JWST yet, $\sim20$ times larger than previous studies, and allows us to examine in detail how galaxy structure has changed over this critical epoch. All sources were classified by six individual classifiers using a simple classification scheme aimed to produce disk/spheroid/peculiar classifications, whereby we determine how the relative number of these morphologies evolves since the Universe's first billion years. Additionally, we explore structural and quantitative morphology measurements using \textsc{Morfometryka}, and show that galaxies at $z > 3$ are not dominated by irregular and peculiar structures, either visually or quantitatively, as previously thought. We find a strong dominance of morphologically selected disk galaxies up to $z = 8$, a far higher redshift than previously thought possible. We also find that the stellar mass and star formation rate densities are dominated by disk galaxies up to $z \sim 6$, demonstrating that most stars in the universe were likely formed in a disk galaxy. We compare our results to theory to show that the fraction of types we find is predicted by cosmological simulations, and that the Hubble Sequence was already in place as early as one billion years after the Big Bang. Additionally, we make our visual classifications public for the community.

In the context of particle acceleration in high-energy astrophysical environments featuring magnetic reconnection, the importance of the resistive term of the electric field compared to the convective one is still under debate. In this work, we present a quantitative analysis through 2D magnetohydrodynamic numerical simulations of tearing-unstable current sheets coupled to a test-particles approach, performed with the PLUTO code. We find that the resistive field plays a significant role in the early-stage energization of high-energy particles. Indeed, these particles are firstly accelerated due to the resistive electric field when they cross an X-point, created during the fragmentation of the current sheet. If this preliminary particle acceleration mechanism dominated by the resistive field is neglected, particles cannot reach the same high energies. Our results support therefore the conclusion that the resistive field is not only non-negligible but it does actually play an important role in the particle acceleration mechanism.

We explore a novel IR phase of electromagnetism and place constraints on it. The usual IR modification of electromagnetism, the Higgs phase, involves adding a photon mass for the gauge field $A_\mu$, which screens electric fields and confines magnetic fields. We explore the confined phase resulting from adding a mass term for the dual photon, which screens magnetic fields and confines electric fields. We study the theory of a dual photon mass and argue that it is a consistent effective field theory. We then elucidate the phenomenological consequences of such a mass term and derive constraints on it. As the current constraints come with large uncertainties, we also propose a few new searches for a dual photon mass term.

We summarise the recent progress of the Axion Longitudinal Plasma HAloscope (ALPHA) Consortium, a new experimental collaboration to build a plasma haloscope to search for axions and dark photons. The plasma haloscope is a novel method for the detection of the resonant conversion of light dark matter to photons. ALPHA will be sensitive to QCD axions over almost a decade of parameter space, potentially discovering dark matter and resolving the Strong CP problem. Unlike traditional cavity haloscopes, which are generally limited in volume by the Compton wavelength of the dark matter, plasma haloscopes use a wire metamaterial to create a tuneable artificial plasma frequency, decoupling the wavelength of light from the Compton wavelength and allowing for much stronger signals. We develop the theoretical foundations of plasma haloscopes and discuss recent experimental progress. Finally, we outline a baseline design for ALPHA and show that a full-scale experiment could discover QCD axions over almost a decade of parameter space.

We derive consistency conditions for sustained slow roll and rapid turn inflation in two-field cosmological models with oriented scalar field space, which imply that inflationary models with field-space trajectories of this type are non-generic. In particular, we show that third order adiabatic slow roll, together with large and slowly varying turn rate, requires the scalar potential of the model to satisfy a certain nonlinear second order PDE, whose coefficients depend on the scalar field metric. We also derive consistency conditions for circular rapid turn trajectories with slow roll in two-field models with rotationally invariant field space metric as well as consistency conditions for slow roll inflationary solutions in the so called ``rapid turn attractor'' approximation. Finally, we argue that the rapid turn regime tends to have a natural exit after a limited number of e-folds.

This paper describes the wide-field three-color observations of an expanded field of noctilucent clouds modulated by a one-dimensional gravity wave. Long wave crests were aligned by a small angle to the solar vertical in the sky. This made possible separate determination of altitude and particle size at different wave phases based on three-color photometry of noctilucent clouds. Thereby, it is possible to use simple optical imaging to record the changes in the parameters of noctilucent clouds when a short-period gravity wave passes by.

In this work, we explored the effect of the fuzzy dark matter (FDM) (or wave dark matter) halo on a supermassive black hole (SMBH). Such a dark matter introduces a soliton core density profile, and we treat it ideally as a spherical distribution that surrounds the SMBH located at its center. In this direction, we obtained a new metric due to the union of the black hole and dark matter spacetime geometries. We applied the solution to the two known SMBH - Sgr. A* and M87* and used the empirical data for the shadow diameter by EHT to constrain the soliton core radius $r_\text{c}$ given some values of the boson mass $m_\text{b}$. Then, we examine the behavior of the shadow radius based on such constraints and relative to a static observer. We found that different shadow sizes are perceived at regions $r_\text{obs}<r_\text{c}$ and $r_\text{obs}>r_\text{c}$, and the deviation is greater for values $m_\text{b}<10^{-22}$ eV. Concerning the shadow behavior, we have also analyzed the effect of the soliton profile on the thin-accretion disk. Soliton dark matter effects manifest through the varying luminosity near the event horizon. We also analyzed the weak deflection angle and the produced Einstein rings due to soliton effects. We found considerable deviation, better than the shadow size deviation, for the light source near the SMBH with impact parameters comparable to the soliton core. Our results suggest the possible experimental detection of soliton dark matter effects using an SMBH at the galactic centers.

Trivial choreographies are special periodic solutions of the planar three-body problem. In this work we use a modified Newton's method based on the continuous analog of Newton's method and a high precision arithmetic for a specialized numerical search for new trivial choreographies. As a result of the search we computed a high precision database of 462 such orbits, including 397 new ones. The initial conditions and the periods of all found solutions are given with 180 correct decimal digits. 108 of the choreographies are linearly stable, including 99 new ones. The linear stability is tested by a high precision computing of the eigenvalues of the monodromy matrices.

Beyond individually resolvable gravitational wave events such as binary black hole and binary neutron star mergers, the superposition of many more weak signals coming from a multitude of sources is expected to contribute to an overall background, the so-called stochastic gravitational wave background. In this review, we give an overview of possible detection methods in the search for this background and provide a detailed review of the data-analysis techniques, focusing primarily on current Earth-based interferometric gravitational-wave detectors. In addition, various validation techniques aimed at reinforcing the claim of a detection of such a background are discussed as well. We conclude this review by listing some of the astrophysical and cosmological implications resulting from current upper limits on the stochastic background of gravitational waves.

In modified gravity, the one-loop matter power spectrum exhibits an ultraviolet divergence as shown in the framework of the degenerate higher-order scalar-tensor theory. To address this problem, we extend the effective field theory of large scale structure to modified gravity theories. We find that new counterterms appear and renormalize the ultraviolet divergence as a natural consequence of non-linearity in the modified Poisson equation. The renormalized one-loop matter power spectrum is useful to test modified gravity theories by comparing to observations.

We consider ${\cal{R}}^2$-inflation in Palatini gravity, in the presence of scalar fields coupled to gravity. These theories, in the Einstein frame, and for one scalar field $h$, share common features with $K$ - inflation models. We apply this formalism for the study of single-field inflationary models, whose potentials are monomials, $ V \sim h^{n} $, with $ n $ a positive even integer. We also study the Higgs model non-minimally coupled to gravity. With ${\cal{R}}^2$-terms coupled to gravity as $\sim \alpha {\cal{R}}^2 $, with $\alpha$ constant, the instantaneous reheating temperature $T_{ins}$, is bounded by $ T_{ins} \leq { 0.290 \, m_{Planck}} / {\, \alpha^{1/4}} $, with the upper bound being saturated for large $\alpha$. For such large $\alpha$ need go beyond slow-roll to calculate reliably the cosmological parameters, among these the end of inflation through which $T_{ins}$ is determined. In fact, as inflaton rolls towards the end of inflation point, the quartic in the velocity terms, unavoidable in Palatini gravity, play a significant role and can not be ignored. The values of $\alpha$, and other parameters, are constrained by cosmological data, setting bounds on the inflationary scale $M_{s} \sim 1/\sqrt{\alpha}$ and the reheating temperature of the Universe.

Exploring the expansion history of the universe, understanding its evolutionary stages, and predicting its future evolution are important goals in astrophysics. Today, machine learning tools are used to help achieving these goals by analyzing transient sources, which are modeled as uncertain time series. Although black-box methods achieve appreciable performance, existing interpretable time series methods failed to obtain acceptable performance for this type of data. Furthermore, data uncertainty is rarely taken into account in these methods. In this work, we propose an uncertaintyaware subsequence based model which achieves a classification comparable to that of state-of-the-art methods. Unlike conformal learning which estimates model uncertainty on predictions, our method takes data uncertainty as additional input. Moreover, our approach is explainable-by-design, giving domain experts the ability to inspect the model and explain its predictions. The explainability of the proposed method has also the potential to inspire new developments in theoretical astrophysics modeling by suggesting important subsequences which depict details of light curve shapes. The dataset, the source code of our experiment, and the results are made available on a public repository.