Papers for Monday, May 27 2024

We present an updated characterization of the TOI-1685 planetary system, which consists of a P$_{\rm{b}}$ = 0.69\,day USP super-Earth planet orbiting a nearby ($d$ = 37.6\,pc) M2.5V star (TIC 28900646, 2MASS J04342248+4302148). This planet was previously featured in two contemporaneous discovery papers, but the best-fit planet mass, radius, and bulk density values were discrepant allowing it to be interpreted either as a hot, bare rock or a 50\% H$_{2}$O / 50\% MgSiO$_{3}$ water world. TOI-1685 b will be observed in three independent JWST cycle two programs, two of which assume the planet is a water world while the third assumes that it is a hot rocky planet. Here we include a refined stellar classification with a focus on addressing the host star's metallicity, an updated planet radius measurement that includes two sectors of TESS data and multi-color photometry from a variety of ground-based facilities, and a more accurate dynamical mass measurement from a combined CARMENES, IRD, and MAROON-X radial velocity data set. We find that the star is very metal-rich ([Fe/H] $\simeq$ +0.3) and that the planet is systematically smaller, lower mass, and higher density than initially reported, with new best-fit parameters of \Rpl = 1.468 $^{+0.050}_{-0.051}$ \Rearth\ and \Mpl = 3.03$^{+0.33}_{-0.32}$ \Mearth. These results fall in between the previously derived values and suggest that TOI-1685 b is a hot, rocky, planet with an Earth-like density (\Rhopl = 5.3 $\pm$ 0.8 g cm$^{-3}$, or 0.96 \rhoearth), high equilibrium temperature (T$_{\rm{eq}}$ = 1062 $\pm$ 27 K) and negligible volatiles, rather than a water world.

Project Hephaistos recently identified seven M-dwarfs as possible Dyson Spheres (DS) candidates. We have cross-matched three of these candidates (A, B \& G) with radio sources detected in various all-sky surveys. The radio sources are offset from the Gaia stellar positions by $\sim 4.9$, $\sim 0.4$ and $\sim 5.0$ arcseconds for candidates A, B, and G respectively. We propose that DOGs (Dust obscured galaxies) lying close to the line-of-sight of these M-dwarf stars significantly contribute to the measured WISE mid-IR flux densities in the WISE W3 and W4 wavebands. These three stars have therefore been misidentified as DS candidates. We also note that with an areal sky density of $9 \times 10^{-6}$ per square arcsecond, Hot DOGs can probably account for the contamination of all 7 DS candidates drawn from an original sample of 5 million stars.

This work presents AstroPT, an autoregressive pretrained transformer developed with astronomical use-cases in mind. The AstroPT models presented here have been pretrained on 8.6 million $512 \times 512$ pixel $grz$-band galaxy postage stamp observations from the DESI Legacy Survey DR8. We train a selection of foundation models of increasing size from 1 million to 2.1 billion parameters, and find that AstroPT follows a similar saturating log-log scaling law to textual models. We also find that the models' performances on downstream tasks as measured by linear probing improves with model size up to the model parameter saturation point. We believe that collaborative community development paves the best route towards realising an open source `Large Observation Model' -- a model trained on data taken from the observational sciences at the scale seen in natural language processing. To this end, we release the source code, weights, and dataset for AstroPT under the MIT license, and invite potential collaborators to join us in collectively building and researching these models.

We search for globular clusters (GCs) trapped in resonances with the bar of the Milky Way. By integrating their orbits in a potential with a decelerating bar, we select 10 whose orbits are significantly changed by its presence. Most of these are trapped in the corotation resonance (CR), including M22 and 47 Tuc. The decelerating bar is capable of transporting these GCs to their current positions from much lower energies, angular momenta, and radii. Our results indicate that the bar is likely to have reshaped the Milky Way's globular cluster system via its resonances. We also discuss implications for the origins of specific GCs, including the possible nuclear star cluster M22. Finally, we consider the effects of the bar on the tidal tails of a trapped GC, by running simulations of stars stripped from 47 Tuc. Instead of forming narrow tails, the stripped stars make up a diffuse extended halo around the cluster, consistent with observations of 47 Tuc.

Over-ionized, recombining plasma is an emerging class of X-ray bright supernova remnants (SNRs). This unique thermal state where the ionization temperature ($T_{\rm z}$) is significantly higher than the electron temperature ($T_{\rm e}$) is not expected from the standard evolution model assuming a point explosion in a uniform interstellar medium, requiring a new scenario for the dynamical and thermal evolution. A recently proposed idea attributes the over-ionization state to additional ionization contribution from the low-energy tail of shock-accelerated protons. However, this new scenario has been left untested, especially from the atomic physics point of view. We report calculation results of the proton impact ionization rates of heavy-element ions in ejecta of SNRs. We conservatively estimate the requirement for accelerated protons, and find that their relative number density to thermal electrons needs to be higher than $5~(T_{\rm e}/{\rm 1~keV})\%$ in order to explain the observed over-ionization degree at $T_{\rm z}/T_{\rm e} \ge 2$ for K-shell emission. We conclude that the proton ionization scenario is not feasible because such a high abundance of accelerated protons is prohibited by the injection fraction from thermal to non-thermal energies, which is expected to be $\sim 1\%$ at largest.

At high redshifts ($z\gtrsim12$), the relative velocity between baryons and dark matter (the so-called streaming velocity) significantly affects star formation in low-mass objects. Streaming substantially reduces the abundance of low-mass gas objects while simultaneously allowing for the formation of supersonically-induced gas objects (SIGOs) and their associated star clusters outside of dark matter halos. Here, we present a study of the population-level effects of streaming on star formation within both halos and SIGOs in a set of simulations with and without streaming. Notably, we find that streaming actually enhances star formation within individual halos of all masses at redshifts between $z=12$ and $z=20$. This is demonstrated both as an increased star formation rate per object as well as an enhancement of the Kennicutt-Schmidt relation for objects with streaming. We find that our simulations are consistent with some observations at high redshift, but on a population level, they continue to under-predict star formation relative to the majority of observations. However, simulations of overdense regions (both with and without streaming) agree with observations, suggesting a strategy for extracting information about the overdensity and streaming velocity in a given survey volume in future observations.

Pulsar timing arrays (PTAs) are designed to detect low-frequency gravitational waves (GWs). GWs induce achromatic signals in PTA data, meaning that the timing delays do not depend on radio-frequency. However, pulse arrival times are also affected by radio-frequency dependent "chromatic" noise from sources such as dispersion measure (DM) and scattering delay variations. Furthermore, the characterization of GW signals may be influenced by the choice of chromatic noise model for each pulsar. To better understand this effect, we assess if and how different chromatic noise models affect achromatic noise properties in each pulsar. The models we compare include existing DM models used by NANOGrav and noise models used for the European PTA Data Release 2 (EPTA DR2). We perform this comparison using a subsample of six pulsars from the NANOGrav 15 yr data set, selecting the same six pulsars as from the EPTA DR2 six-pulsar dataset. We find that the choice of chromatic noise model noticeably affects the achromatic noise properties of several pulsars. This is most dramatic for PSR J1713+0747, where the amplitude of its achromatic red noise lowers from $\log_{10}A_{\text{RN}} = -14.1^{+0.1}_{-0.1}$ to $-14.7^{+0.3}_{-0.5}$, and the spectral index broadens from $\gamma_{\text{RN}} = 2.6^{+0.5}_{-0.4}$ to $\gamma_{\text{RN}} = 3.5^{+1.2}_{-0.9}$. We also compare each pulsar's noise properties with those inferred from the EPTA DR2, using the same models. From the discrepancies, we identify potential areas where the noise models could be improved. These results highlight the potential for custom chromatic noise models to improve PTA sensitivity to GWs.

The Orion Molecular Cloud complex, one of the nearest (D~400 pc) and most extensively studied massive star-forming regions, is ideal for constraining the physics of stellar feedback, but its ~12 deg diameter on the sky requires a dedicated approach to mapping ionized gas structures within and around the nebula. The Sloan Digital Sky Survey (SDSS-V) Local Volume Mapper (LVM) is a new optical integral field unit (IFU) that will map the ionized gas within the Milky Way and Local Group galaxies, covering 4300 deg^2 of the sky with the new LVM Instrument (LVM-I). We showcase optical emission line maps from LVM covering 12 deg^2 inside of the Orion belt region, with 195,000 individual spectra combined to produce images at 0.07 pc (35.3 arcsec) resolution. This is the largest IFU map made (to date) of the Milky Way, and contains well-known nebulae (the Horsehead Nebula, Flame Nebula, IC 434, and IC 432), as well as ionized interfaces with the neighboring dense Orion B molecular cloud. We resolve the ionization structure of each nebula, and map the increase in both the [SII]/Ha and [NII]/Ha line ratios at the outskirts of nebulae and along the ionization front with Orion B. [OIII] line emission is only spatially resolved within the center of the Flame Nebula and IC 434, and our ~0.1 pc scale line ratio diagrams show how variations in these diagnostics are lost as we move from the resolved to the integrated view of each nebula. We detect ionized gas emission associated with the dusty bow wave driven ahead of the star sigma Orionis, where the stellar wind interacts with the ambient interstellar medium. The Horsehead Nebula is seen as a dark occlusion of the bright surrounding photo-disassociation region. This small glimpse into Orion only hints at the rich science that will be enabled by the LVM.

Boundaries of galaxy groups and clusters are defined by the interplay between the Newtonian attractive force and the local repulsion force caused by the expansion of the Universe. This research extends the definition of zero radial acceleration surface (ZRAS) and the turnaround surface (TS) for a general distribution of the masses in an expanding background, governed by the cosmological constant. We apply these definitions for different galaxy groups in the local Universe, mapping these groups up to ten megaparsec. We discuss the dipole and the quadrupole rate for the Local Group of Galaxies and the implementations for Hubble diagram correction and galaxy groups viralization. With these definitions, we indicate the surfaces showing the interplay between the local expansion vs the local Newtonian attraction for galaxy groups in the local Universe. The results show that it is important to include the cosmological constant in analyzing the Cosmic Flow of the local Universe.

Resolving the formation channel(s) of merging binary black holes is a key goal in gravitational-wave astronomy. The orbital eccentricity is believed to be a precious tracer of the underlying formation pathway, but is largely dissipated during the usually long inspiral between black-hole formation and merger. Most gravitational-wave sources are thus expected to enter the sensitivity windows of current detectors on configurations that are compatible with quasi-circular orbits. In this paper, we investigate the impact of "negligible" residual eccentricity -- lower than currently detectable by LIGO/Virgo -- on our ability to infer the formation history of binary black holes, focusing in particular on their spin orientations. We trace the evolution of both observed and synthetic gravitational-wave events backward in time, while resampling their residual eccentricities to values that are below the detectability threshold. Eccentricities in-band as low as $\sim 10^{-4}$ can lead to significant biases when reconstructing the spin directions, especially in the case of loud, highly precessing systems. Residual eccentricity thus act like a systematic uncertainty for our astrophysical inference. As a mitigation strategy, one can marginalize the posterior distribution over the residual eccentricity using astrophysical predictions.

Using the SMUDGes and SDSS catalogs, and our own reprocessing of the Legacy Surveys imaging, we investigate the properties of nuclear star clusters (NSCs) in galaxies having central surface brightnesses as low as 27 mag arcsec$^{-2}$. We identify 273 (123 with known redshift) and 32 NSC-bearing galaxies in the two samples, respectively, where we require candidate NSCs to have a separation of less than 0.10$r_e$ from the galaxy center. We find that galaxies with low central surface brightness ($\mu_{0,g} > 24$ mag arcsec$^{-2}$) are more likely to contain an NSC if 1) they have a higher stellar mass, 2) a higher stellar to total mass ratio, 3) a brighter central surface brightness, 4) a larger axis ratio, or 5) lie in a denser environment. Because of the correlations among these various quantities, it is likely that only one or two are true physical drivers. We also find scaling relations for the NSC mass with stellar mass ($M_{NSC}/$\Msol$ = 10^{6.02\pm0.03}(M_{*,gal}/10^{8} $\Msol$)^{0.77\pm0.04}$) and halo mass ($M_{NSC}/$\Msol$ = 10^{6.11\pm0.05}(M_{h,gal}/10^{10} $\Msol$)^{0.92\pm0.05}$), although it is the scaling with halo mass that is consistent with a direct proportionality. In galaxies with an NSC, $M_{NSC} \approx 10^{-4}M_{h,gal}$. This proportionality echoes the finding of a direct proportionality between the mass (or number) of globular clusters (GCs) in galaxies and the galaxy's total mass. These findings favor a related origin for GCs and NSCs.

PSR J0837-2454 is a young 629 ms radio pulsar whose uncertain distance has important implications. A large distance would place the pulsar far out of the Galactic plane and suggest it is the result of a runaway star, while a short distance would mean the pulsar is extraordinarily cold. Here we present further radio observations and the first deep X-ray observation of PSR J0837-2454. Data from the Parkes Murriyang telescope show flux variations over short and long timescales and also yield an updated timing model, while the position and proper motion (and, less strongly, parallax) of the pulsar are constrained by a number of low-significance detections with the Very Long Baseline Array. XMM-Newton data enable detection of X-ray pulsations for the first time from this pulsar and yield a spectrum that is thermal and blackbody-like, with a cool blackbody temperature ~70 eV or atmosphere temperature ~50 eV, as well as a small hotspot. The spectrum also indicates the pulsar is at a small distance of <~1 kpc, which is compatible with the marginal VLBA parallax constraint that favours a distance of >~330 pc. The low implied X-ray luminosity (~3x10^31 erg s^-1 at 0.9 kpc) suggests PSR J0837-2454 has a mass high enough that fast neutrino emission from direct Urca reactions operates in this young star and points to a nuclear equation of state that allows for direct Urca reactions at the highest densities present in neutron star cores.

Astrophysics demands higher precision in measurements across photometry, spectroscopy, and astrometry. Several science cases necessitate not only precision but also a high level of accuracy. We highlight the challenges involved, particularly in achieving spectral fidelity, which refers to our ability to accurately replicate the input spectrum of an astrophysical source. Beyond wavelength calibration, this encompasses correcting observed spectra for atmospheric, telescope, and instrumental signatures. Elevating spectral fidelity opens avenues for addressing fundamental questions in physics and astrophysics. We delve into specific science cases, critically analyzing the prerequisites for conducting crucial observations. Special attention is given to the requirements for spectrograph detectors, their calibrations and data reduction. Importantly, these considerations align closely with the needs of photometry and astrometry.

Axion-inflation models are a compelling candidate as a mechanism behind the accelerated expansion in the early universe in light of the possibility to embed them in higher dimensional UV complete theories and the exciting prospect of testing them with next-generation cosmological probes. Adding an Abelian gauge sector to axion-inflation models makes for a rich, interesting, phenomenology spanning from primordial black holes to gravitational waves (GWs). Several recent studies employ an approximate analytic (Gaussian) template to characterize the effect of gauge field production on cosmological perturbations. In this work we go beyond such approximation and numerically study particle production and the ensuing scalar and tensor spectra. We find a significant deviation from results based on log-normally distributed vector field excitations. As an important phenomenological application of the improved method, we study the expected chirality and spectral index of the sourced GW background at scales relevant for current and next-generation GW detectors. One striking feature is that of a scale-dependent chirality. We derive a consistency relation between these two observables that can serve as an important tool in identifying key signatures of multi-field dynamics in axion inflation.

Kpc-scale dual and offset Active Galactic Nuclei (AGNs) are signposts of accreting supermassive black holes (SMBHs) triggered during late-stage galaxy mergers, offering crucial insights into the coevolution of SMBHs and galaxies. However, robustly confirmed systems at high redshift (e.g., $z>1$) are scarce and biased towards the most luminous and unobscured systems. In this study, we systematically search for kpc-scale (projected separation $<15$ kpc) dual and offset AGNs around 571 moderate-luminosity, X-ray-selected AGNs including the obscured population, utilizing deep HST ACS/F814W and multiband JWST NIRCam imaging from the COSMOS-Web survey. We identify 59 dual and 30 offset AGN candidates in late stage major mergers based on spatially-resolved spectral energy distribution analyses. This translates to $\sim28$ and $\sim10$ bona-fide dual and offset AGNs using a probabilistic pair counting scheme to minimize chance superpositions. Notably, the fraction of dual and offset AGNs among moderate-luminosity ($L_{\rm bol}\sim10^{43}-10^{46}\ \rm erg\ s^{-1}$), obscured AGNs is nearly two orders of magnitude higher than that of the most luminous, unobscured quasar pairs. We find tentative evidence for an increasing pair fraction among AGNs with redshift (from a few percent at $z\sim 0.5$ to $\sim22.9_{-17.7}^{+27.5}\%$ at $z\sim4.5$) and a higher occurrence rate of dual over offset AGNs. There is no pileup of dual/offset AGNs below $\sim 2~{\rm kpc}$ separations. These results generally align with predictions from the ASTRID and Horizon-AGN cosmological simulations when matching sample selection criteria, implying a high probability of both BHs being active simultaneously in late-stage major mergers.

The solar eruption that occurred on 2023 November 28 (SOL2023-11-28) triggered an intense geomagnetic storm on Earth on 2023 December 1. The associated Earth's auroras manifested at the most southern latitudes in the northern hemisphere observed in the past two decades. In order to explore the profound geoeffectiveness of this event, we conducted a comprehensive analysis of its solar origin to offer potential factors contributing to its impact. Magnetic flux ropes (MFRs) are twisted magnetic structures recognized as significant contributors to coronal mass ejections (CMEs), thereby impacting space weather greatly. In this event, we identified multiple MFRs in the solar active region and observed distinct slipping processes of the three MFRs: MFR1, MFR2, and MFR3. All three MFRs exhibit slipping motions at a speed of 40--137 km s$^{-1}$, extending beyond their original locations. Notably, the slipping of MFR2 extends to $\sim$30 Mm and initiate the eruption of MFR3. Ultimately, MFR1's eruption results in an M3.4-class flare and a CME, while MFR2 and MFR3 collectively produce an M9.8-class flare and another halo CME. This study shows the slipping process in a multi-MFR system, showing how one MFR's slipping can trigger the eruption of another MFR. We propose that the CME--CME interactions caused by multiple MFR eruptions may contribute to the significant geoeffectiveness.

Gravitational microlensing is a robust tool to detect and directly measure the abundance and mass of any kind of compact objects, either in our galaxy or in the extragalatic domain. On basis to generic, broadly applicable arguments, it is concluded that the observed microlensing magnifications are too small and the microlensing events less frequent than the expectations for a significant population of compact objects (other than normal stars). The detection of chromatic effects of microlensing, neither supports the presence of BHs. Detailed statistical studies of the observed microlensing magnifications and events frequency impose strict upper limits to the fraction of total mass of BHs ($\ltsim$ 1\%) from $10^{-7}M_\odot$ to indefinitely large masses. These results hold even when the BHs are distributed according to a mass spectrum or are forming clusters.

The squeezed cross-bispectrum \bispeconed\ between the gravitational lensing in the Cosmic Microwave Background and the 1D \lya\ forest power spectrum can constrain bias parameters and break degeneracies between $\sigma_8$ and other cosmological parameters. We detect \bispeconed\ with $4.8\sigma$ significance at an effective redshift $z_\mathrm{eff}=2.4$ using Planck PR3 lensing map and over 280,000 quasar spectra from the Dark Energy Spectroscopic Instrument's first-year data. We test our measurement against metal contamination and foregrounds such as Galactic extinction and clusters of galaxies by deprojecting the thermal Sunyaev-Zeldovich effect. We compare our results to a tree-level perturbation theory calculation and find reasonable agreement between the model and measurement.

NASA's Transiting Exoplanet Survey Satellite (TESS) has identified over 7,000 candidate exoplanets via the transit method, with gas giants among the most readily detected due to their large radii. Even so, long intervals between TESS observations for much of the sky lead to candidates for which only a single transit is detected in one TESS sector, leaving those candidate exoplanets with unconstrained orbital periods. Here, we confirm the planetary nature of TIC 393818343 b, originally identified via a single TESS transit, using radial velocity data and ground-based photometric observations from citizen scientists with the Unistellar Network and Exoplanet Watch. We determine a period of $P$ = 16.24921 $\substack{+0.00010 \\ -0.00011}$ days, a mass $M_{P}$ = 4.34 $\pm$ 0.15 $M_{J}$, and semi-major axis $a$ = 0.1291 $\substack{+0.0021 \\ -0.0022}$ au, placing TIC 393818343 b in the "warm Jupiter" population of exoplanets. With an eccentricity $e$ = 0.6058 $\pm$ 0.0023, TIC 393818343 b is the most eccentric warm Jupiter to be discovered by TESS orbiting less than 0.15 au from its host star and therefore an excellent candidate for follow-up, as it may inform our future understanding of how hot and warm Jupiter populations are linked.

On 18 May 2024, a superbolide traversed the western part of the Iberian Peninsula, culminating its flight over the Atlantic Ocean and generating significant media attention. This event was caused by a weak carbonaceous meteoroid of 93.0$\pm$0.8 cm, with a density of 1613$\pm$12 kg\,m$^{-3}$, entering the atmosphere at 40.1$\pm$0.4 km\,s$^{-1}$ with an angle of 10.93$\pm$0.02$^\circ$. The luminous phase started at 137.88$\pm$0.05 km and ended at an altitude of 53.78$\pm$0.07 km. The meteoroid's heliocentric orbit was characterized by an inclination of 14.42$\pm$0.23$^\circ$, a high eccentricity of 0.950$\pm$0.004, a semi-major axis of 2.31$\pm$0.13 au, and a notably short perihelion distance of 0.116$\pm$0.003 au. The superbolide was recorded by multiple ground-based stations of the Spanish Meteor Network (SPMN), the European Space Agency (ESA), and the U.S. Government (USG) space sensors. Our analysis shows a good agreement with the radiant and velocity data reported by the Center for Near-Earth Object Studies (CNEOS), with a deviation of 1.6$^\circ$ and -0.4 km\,s$^{-1}$, respectively. Due to the absence of observable deceleration, we successfully reconciled satellite radiometric data with a purely dynamic atmospheric flight model, constraining the meteoroid's mass and coherently fitting its velocity profile.

Understanding the nature of the luminous 1991T-like supernovae is of great importance to supernova cosmology as they are likely to have been more common in the early universe. In this paper we explore the observational properties of 1991T-like supernovae to study their relationship to other luminous, slow-declining Type~Ia supernovae (SNe Ia). From the spectroscopic and photometric criteria defined in Phillips et al. (1992), we identify 17 1991T-like supernovae from the literature. Combining these objects with ten 1991T-like supernovae from the Carnegie Supernova Project-II, the spectra, light curves, and colors of these events, along with their host galaxy properties, are examined in detail. We conclude that 1991T-like supernovae are closely related in essentially all of their UV, optical, and near-infrared properties -- as well as their host galaxy parameters -- to the slow-declining subset of Branch core-normal supernovae and to the intermediate 1999aa-like events, forming a continuum of luminous SNe Ia. The overriding difference between these three subgroups appears to be the extent to which $^{56}$Ni mixes into the ejecta, producing the pre-maximum spectra dominated by Fe III absorption, the broader UV light curves, and the higher luminosities that characterize the 1991T-like events. Nevertheless, the association of 1991T-like SNe with the rare Type Ia CSM supernovae would seem to run counter to this hypothesis, in which case 1991T-like events may form a separate subclass of SNe Ia, possibly arising from single-degenerate progenitor systems.

Recent cosmological hydrodynamic simulations have suggested that the first stars in the universe often form as binary or multiple systems. However, previous studies typically overlooked the potential influence of magnetic fields during this process, assuming them to be weak and minimally impactful. Emerging theoretical investigations, however, propose an alternative perspective, suggesting that turbulent dynamo effects within first-star forming clouds can generate strong magnetic fields. In this study, we perform three-dimensional ideal magnetohydrodynamics simulations, starting from the gravitational collapse of a turbulent cloud core to the early accretion phase, where disk fragmentation frequently occurs. Our findings reveal that turbulent magnetic fields, if they reach an equipartition level with turbulence energy across all scales during the collapse phase, can significantly affect the properties of the multiple systems. Specifically, both magnetic pressure and torques contribute to disk stabilization, leading to a reduction in the number of fragments, particularly for low-mass stars. Additionally, our observations indicate the launching of protostellar jets driven by magnetic pressure of toroidal fields, although their overall impact on star formation dynamics appears to be minor. Given the case with which seed magnetic fields amplify to the full equipartition level, our results suggest that magnetic fields likely play a significant role in shaping the initial mass function of the first stars, highlighting the importance of magnetic effects on star formation in the early universe.

The upcoming generation of telescopes, instruments, and surveys is poised to usher in an unprecedented "Big Data" era in the field of astronomy. Within this context, even seemingly modest tasks such as spectral line analyses could become increasingly challenging for astronomers. In this paper, we announce the release of ${\rm L{\small I}M{\small E}}$. This package is tailored for multidisciplinary observations with long-slit and integral field spectroscopy (IFS) support. ${\rm L{\small I}M{\small E}}$ functions encompass the reading of observational files, detecting lines, conditioned line fitting, and the plotting and storage of results. Most importantly, these measurements are structured to support the subsequent chemical and kinematic analyses. To reduce the coding effort required from users, we introduced a notation system for atomic transitions that is accessible to humans and machine-readable. Along with this system, we present an extensive database of line bands, spanning from the ultraviolet to the infrared wavelength range. Additionally, we propose a model designed to train machine learning algorithms in line detection. ${\rm L{\small I}M{\small E}}$ features a comprehensive online documentation, which details the command attributes and includes several tutorials. These tutorials range from measuring a single line to analyzing an entire IFS data cube. This library functions and measurements are showcased in an online virtual observatory. The data in this interactive website come from the JWST NIRSpec observations of the CEERs survey. In this regard, ${\rm L{\small I}M{\small E}}$ offers improvements related to the dissemination and accessibility of astronomical spectra.

In this work, we propose a deep learning-based classification model of astronomical objects using alerts reported by the Zwicky Transient Facility (ZTF) survey. The model takes as inputs sequences of stamp images and metadata contained in each alert, as well as features from the All-WISE catalog. The proposed model, called temporal stamp classifier, is able to discriminate between three classes of astronomical objects: Active Galactic Nuclei (AGN), Super-Novae (SNe) and Variable Stars (VS), with an accuracy of approximately 98% in the test set, when using 2 to 5 detections. The results show that the model performance improves with the addition of more detections. Simple recurrence models obtain competitive results with those of more complex models such as LSTM.We also propose changes to the original stamp classifier model, which only uses the first detection. The performance of the latter model improves with changes in the architecture and the addition of random rotations, achieving a 1.46% increase in test accuracy.

Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous component of the interstellar medium (ISM) in z~0 massive, star-forming galaxies and play key roles in ISM energy balance, chemistry, and shielding. Wide field of view, high resolution mid-infrared (MIR) images from JWST provides the ability to map the fraction of dust in the form of PAHs and the properties of these key dust grains at 10-50 pc resolution in galaxies outside the Local Group. We use MIR JWST photometric observations of a sample of 19 nearby galaxies from the "Physics at High Angular Resolution in Nearby GalaxieS" (PHANGS) survey to investigate the variations of the PAH fraction. By comparison to lower resolution far-IR mapping, we show that a combination of the MIRI filters (R$_{\rm{PAH}}$ = [F770W+F1130W]/F2100W) traces the fraction of dust by mass in the form of PAHs (i.e., the PAH fraction, or q$_{\rm{PAH}}$). Mapping R$_{\rm{PAH}}$ across the 19 PHANGS galaxies, we find that the PAH fraction steeply decreases in HII regions, revealing the destruction of these small grains in regions of ionized gas. Outside HII regions, we find R$_{\rm{PAH}}$ is constant across the PHANGS sample with an average value of 3.43$\pm$0.98, which, for an illuminating radiation field of intensity 2-5 times that of the radiation field in the solar neighborhood, corresponds to q$_{\rm{PAH}}$ values of 3-6%.

Particle acceleration and magnetic field amplification in relativistic shocks propagating in inhomogeneous media are investigated by three-dimensional magnetohydrodynamical (MHD) simulations and test-particle simulations. The MHD simulations show that the interaction between the relativistic shock and dense clumps amplifies the downstream magnetic field to the value expected from observations of the gamma-ray burst. The test-particle simulations in the electromagnetic field given by the MHD simulation show that particles are accelerated by the downstream turbulence and the relativistic shock. We provide the injection energy to the shock acceleration in this system. If the amplitude of upstream density fluctuations is sufficiently large, low-energy particles are initially accelerated to the injection energy by the downstream turbulence and then rapidly accelerated to higher energies by the relativistic shock. Therefore, the density fluctuation significantly affects particle acceleration in the relativistic shock.

The formation of the Inner Oort Cloud (IOC) - a vast halo of icy bodies residing far beyond Neptune's orbit - is an expected outcome of the solar system's primordial evolution within a stellar cluster. Recent models have shown that the process of early planetesimal capture within the trans-Neptunian region may have been sufficiently high for the cumulative mass of the Cloud to approach several Earth masses. In light of this, here we examine the dynamical evolution of the IOC, driven by its own self-gravity. We show that the collective gravitational potential of the IOC is adequately approximated by the Miyamoto-Nagai model, and use a semi-analytic framework to demonstrate that the resulting secular oscillations are akin to the von Zeipel-Lidov-Kozai resonance. We verify our results with direct $N$-body calculations, and examine the effects of IOC self-gravity on the long-term behavior of the solar system's minor bodies using a detailed simulation. Cumulatively, we find that while the modulation of perihelion distances and inclinations can occur within an observationally relevant range, the associated timescales vastly surpass the age of the sun, indicating that the influence of IOC self-gravity on the architecture of the solar system is negligible.

A warm corona has been widely proposed to explain the soft X-ray excess (SE) above the 2--10 keV power law extrapolation in AGNs. In actual spectral fittings, the warm coronal seed photon temperature ($T_{\rm s}$) is usually assumed to be far away from the soft X-ray, but $kT_{\rm s}$ can reach close to 0.1 keV in standard accretion disc model. In this study, we used Monte Carlo simulations to obtain radiation spectra from a slab-like warm corona and fitted the spectra using the spherical-geometry-based routine \textsc{thcomp} or a thermal component. Our findings reveal that high $T_{\rm s}$ can influence the fitting results. A moderately high $kT_{\rm s}$ (around 0.03 keV) can result in an apparent low-temperature and flat SE, while an extremely high $kT_{\rm s}$ (around 0.07 keV) can even produce an unobserved blackbody-like SE. Our conclusions indicate that, for spectral fittings of the warm coronal radiation (SE in AGNs), $kT_{\rm s}$ should be treated as a free parameter with an upper limit, and an accurate coronal geometry is necessary when $kT_{\rm s}>0.01$ keV.

Asteroseismology offers a profound window into stellar interiors and has emerged as a pivotal technique in exoplanetary research. This study harnesses the Transiting Exoplanet Survey Satellite (TESS) observations to reveal, for the first time, the asteroseismic oscillations of four exoplanet-hosting stars. Through meticulous analysis, we extracted their asteroseismic signatures, enabling the precise determination of stellar masses, radii, luminosities, and surface gravities. These parameters exhibit markedly reduced uncertainties compared to those derived from spectroscopic methods. Crucially, the exoplanets orbiting these stars were initially identified via radial velocity measurements. The refinement of host stellar masses necessitates a corresponding adjustment in planetary characteristics. Employing asteroseismology, we recalibrated the exoplanets' minimum masses and semi-major axes - a novel approach in the field. For instance, the exoplanet HD 5608 b's minimum mass, denoted as Msini, was ascertained to be 1.421 +/- 0.091 M_J through the integration of asteroseismic and radial velocity data. Similarly, two planets within the 7 CMa system yielded Msini values of 1.940 +/- 0.064 MJ and 0.912 +/- 0.067 M_J, respectively. Two planets in HD 33844 system presented Msini figures of 1.726 +/- 0.145 M_J and 1.541 +/- 0.182 M_J, while the HIP 67851 system's planets registered Msini at 1.243 +/- 0.139 M_J and a notably higher 5.387 +/- 0.699 M_J. This investigation extends beyond mere parameter refinement; it underscores the synergy between asteroseismology and exoplanetology, yielding unprecedented precision in system metrics. Focusing on quartet of K-type giants in advanced evolutionary phases, our work positions these systems as invaluable astrophysical laboratories, offering insights into the potential trajectory of our own solar system's fate.

The stellar-to-halo mass relation (SHMR) is a fundamental relationship between galaxies and their host dark matter haloes. In this study, we examine the scatter in this relation for primary galaxies in the semi-analytic L-Galaxies model and two cosmological hydrodynamical simulations, \eagle{} and \tng{}. We find that in low-mass haloes, more massive galaxies tend to reside in haloes with higher concentration, earlier formation time, greater environmental density, earlier major mergers, and, to have older stellar populations, which is consistent with findings in various studies. Quantitative analysis reveals the varying significance of halo and galaxy properties in determining SHMR scatter across simulations and models. In \eagle{} and \tng{}, halo concentration and formation time primarily influence SHMR scatter for haloes with $M_{\rm h}<10^{12}~\rm M_\odot$, but the influence diminishes at high mass. Baryonic processes play a more significant role in \lgal{}. For halos with $M_{\rm h} <10^{11}~\rm M_\odot$ and $10^{12}~\rm M_\odot<M_{\rm h}<10^{13}~\rm M_\odot$, the main drivers of scatter are galaxy SFR and age. In the $10^{11.5}~\rm M_\odot<M_{\rm h} <10^{12}~\rm M_\odot$ range, halo concentration and formation time are the primary factors. And for halos with $M_{\rm h} > 10^{13}~\rm M_\odot$, supermassive black hole mass becomes more important. Interestingly, it is found that AGN feedback may increase the amplitude of the scatter and decrease the dependence on halo properties at high masses.

We search for gamma-ray emission from OJ287 in the energy range from 0.1-300 GeV during 2015-2023, in coincidence with an extensive observing campaign to monitor the optical flux variability and polarization, as discussed in arXiv:2311.02372. We present results for eight segments in the aforementioned period, with each segment corresponding to an observing season. We find non-zero gamma-ray emission for all the eight segments. The photon and energy flux observed during this period is $\sim 5.2 \times 10^{-8} \rm{ph~cm^{-2}~s^{-1}}$ and $2.75 \times 10^{-5} \rm{MeV~cm^{-2}~s^{-1}}$, respectively, while the SED can be fitted with a power law with a slope of $2.12 \pm 0.02$. The observed luminosity is between $10^{45}-10^{46}$ ergs/sec.

The mass loss rates of planets undergoing core-powered escape are usually modeled using an isothermal Parker-type wind at the equilibrium temperature, $T_\mathrm{eq}$. However, the upper atmospheres of sub-Neptunes may not be isothermal if there are significant differences between the opacity to incident visible and outgoing infrared radiation. We model bolometrically-driven escape using aiolos, a hydrodynamic radiative-transfer code that incorporates double-gray opacities, to investigate the process's dependence on the visible-to-infrared opacity ratio, $\gamma$. For a value of $\gamma \approx 1$, we find that the resulting mass loss rates are well-approximated by a Parker-type wind with an isothermal temperature $T = T_\mathrm{eq}/2^{1/4}$. However, we show that over a range of physically plausible values of $\gamma$, the mass loss rates can vary by orders of magnitude, ranging from $10^{-5} \times$ the isothermal rate for low $\gamma$ to $10^5 \times$ the isothermal rate for high $\gamma$. The differences in mass loss rates are largest for small planet radii, while for large planet radii, mass loss rates become nearly independent of $\gamma$ and approach the isothermal approximation. We incorporate these opacity-dependent mass loss rates into a self-consistent planetary mass and energy evolution model and show that lower/higher $\gamma$ values lead to more/less hydrogen being retained after core-powered mass loss. In some cases, the choice of opacities determines whether or not a planet can retain a significant primordial hydrogen atmosphere. The dependence of escape rate on the opacity ratio may allow atmospheric escape observations to directly constrain a planet's opacities and therefore its atmospheric composition.

Deep-sea archives that include intermediate-lived radioactive $^{60}\mathrm{Fe}$ particles suggest the occurrence of several recent supernovae inside the present-day volume of the Local Bubble during the last $\sim 10$ Myr. The isotope $^{60}\mathrm{Fe}$ is mainly produced in massive stars and ejected in supernova explosions, which should always result in a sizeable yield of $^{26}\mathrm{Al}$ from the same objects. $^{60}\mathrm{Fe}$ and $^{26}\mathrm{Al}$ decay with lifetimes of 3.82 and 1.05 Myr, and emit $\gamma$-rays at 1332 and 1809 keV, respectively. These $\gamma$-rays have been measured as diffuse glow of the Milky Way, and would also be expected from inside the Local Bubble as foreground emission. Based on two scenarios, one employing a geometrical model and the other state-of-the-art hydrodynamics simulations, we estimate the expected fluxes of the 1332 and 1809 keV $\gamma$-ray lines, as well as the resulting 511 keV line from positron annihilation due to the $^{26}\mathrm{Al}$ $\beta^+$-decay. We find fluxes in the range of $10^{-6}$-$10^{-5}\,\mathrm{ph\,cm^{-2}\,s^{-1}}$ for all three lines with isotropic contributions of 10-50%. We show that these fluxes are within reach for the upcoming COSI-SMEX $\gamma$-ray telescope over its nominal satellite mission duration of 2 yr. Given the Local Bubble models considered, we conclude that in the case of 10-20 Myr-old superbubbles, the distributions of $^{60}\mathrm{Fe}$ and $^{26}\mathrm{Al}$ are not co-spatial - an assumption usually made in $\gamma$-ray data analyses. In fact, this should be taken into account however when analysing individual nearby targets for their $^{60}\mathrm{Fe}$ to $^{26}\mathrm{Al}$ flux ratio as this gauges the stellar evolution models and the age of the superbubbles. A flux ratio measured for the Local Bubble could further constrain models of $^{60}\mathrm{Fe}$ deposition on Earth and its moon.

In the present work, we study a cosmological model composed of a viscous dark matter interacting with decaying vacuum energy in a spatially flat Universe. In the first part, we find the analytical solution of different cosmological parameters by assuming the physically viable forms of bulk viscosity and decaying vacuum density with the interaction term. The second part is dedicated to constrain the free parameters of the interacting viscous model with decaying vacuum energy by employing latest observational data of $Pantheon+$, Cosmic Chronometer and $f(z)\sigma_{8}(z)$. We find that the interacting model just deviate very slightly from well-known concordance $\Lambda$CDM model and can alleviate effectively the current $H_0$ tension between local measurement by R21 and global measurement by Planck 2018, and the excess in the mass fluctuation amplitude $\sigma_{8}$ essentially vanish in this context. We report the Hubble constants as $H_0=72.150^{+0.989}_{-0.779}$, and $ 72.202^{+0.796}_{-0.937}$ \;$km s^{-1} Mpc^{-1}$, deceleration parameters as $q_0=-0.533 \pm 0.024$, and $-0.531 \pm 0.024$, and equation of state parameters as $w_0=-0.689 \pm 0.016$, and $ -0.687 \pm 0.016$ for $\Lambda$CDM and interacting models, respectively. It is found that the interacting model is in good agreement with $\Lambda$CDM. Further, we discuss the amplitude of matter power spectrum $\sigma_8$ and its associated parameter $S_8$ using $f(z)\sigma_8(z)$ data. Finally, the information selection criterion and Bayesian inference are discussed to distinguish the interacting model with $\Lambda$CDM model.

We show using superposed epoch analysis (SEA) that the most energetic protons (greater than 60 MeV) in near-Earth IMF have a peak almost immediately (less than a day) after peak in solar flare index (SFI), while protons greater than 10 MeV peak one day after the SFI and protons greater than 1 MeV two days after the SFI. The geomagnetic indices AU, -AL, PC, Ap and -Dst peak after two to three days in SEAs after the peak in SFI. The auroral electrojet indices AU and -AL, however, have only low peaks. Especially, the response of the eastward electrojet, AU, to SFI is negligible compared to other geomagnetic indices. The SEAs of the SFI and cosmic ray counts (CR) show that the deepest decline in the CR intensity follows also with 2-3 day lag the maximum of the SFI for the Solar Cycles 20-24. The depth of the declines are related to the SFI strength of each cycle, i.e, the average decline is about 5% for the Cycles 21 and 22, but only 3% for the Cycle 24. The strongest Cycle 19, however, differs from the other cycles such that it has double-peaked decline and lasts longer than the decline of the other cycles. The double superposed epoch analyses show that the response of IMF Bv2, which is about two days, and CR to SFI are quite simultaneous, but sometimes Bv2 may peak somewhat earlier than the decline existing in CR.

A morphological and photometric analysis of the naked-eye long-period comet C/2022 E3 (ZTF) before perihelion is presented in this study. The observation images taken by the Zwicky Transient Facility survey telescope from July 2022 to October 2022 show a gradually brightening dust coma and a tail with a clear structure. The morphology of the dust coma reveals nonsteady-state emission with an ejection velocity lower than 14 m s$^{-1}$ for particles larger than 100 um. According to the syndyne-synchrone analysis, dust particles larger than about 10 um contribute significantly to the observed tail. The model simulations of the 10 October 2022 image suggest that the radii of large particles lingering near the nucleus range from 0.1 mm to 1 mm. Assuming that the nucleus of comet E3 is a homogeneous sphere with an albedo of 0.1, the photometry analysis sets the lower and upper limits of the nucleus radius to be $0.81\pm0.07$ km and $2.79\pm0.01$ km, respectively. The dust production rates increased continuously from $241\pm3$ kg s$^{-1}$ in July to $476\pm9$ kg s$^{-1}$ in October. The dependence of the ejection velocity $v_{\perp}$ perpendicular to the orbital plane of comet E3 on the particle size $a$ can be simplified as $v_{\perp}\propto a^{-1/2}$, which indicates that the dust emission is likely driven by gas. The water-production rate is inferred as $\sim 368\pm72$ kg s$^{-1}$ in October 2022, which is sustained by an equilibrium-sublimating area of $8.2\times10^6$ m$^2$ at least. The comparative analysis of the characteristics of comet E3 with those of comets belonging to different types shows that the activity profile of long-period comet E3 surprisingly aligns more closely with those of short-period comets within a heliocentric distance range of about [1.7, 3.4] AU, where the images of comet E3 that we used in this study were taken.

We analyse the monthly sunspot group (SG) data for Solar Cycles C8-C23 and calculate the average latitude of the drift path for the northern and southern hemisphere of the Sun. We find that exponential function fits slightly better than the second-order polynomial to the average drift of the SGs. The drift velocities are are 0.30 and 0.27 degrees/month (meridional speed about 1.41 and 1.27 m/s) in the beginning and 0.071 and 0.069 degrees/month (about 0.33 and 0.32 m/s) at the end of the average cycle for northern and southern hemisphere, respectively. We do also bi-linear fits (first-order polynomial fits in two fractions) because they tell us the crossing point were the drift velocity changes the most. This crossing point for the Cycles C8-C23 is at 50 months and 15.4 degrees of latitude in the northern hemisphere and 54 months and -14.4 degrees for the southern hemisphere. The drift velocities calculated from the slopes of the bi-linear fits are 0.233 and 0.216 degrees/month (about 1.10 and 1.02 m/s) before the crossing point and 0.118 and 0.101 degrees/month (about 0.55 and 0.47 m/s) after the crossing point. We find a slight dependence of the migration on the strength of the cycle such that the drift path of the stronger cycles follow slightly higher latitudes than those of the weaker cycles. The areas of the sunspot groups affect also slightly to the drift path such that large area SGs have path at somewhat lower latitudes in the ascending phase and higher latitudes in the descending phase of the cycle than the smaller area SGs.

We have fulfilled a detailed long-slit spectroscopic analysis for two SB0 galaxies -- NGC 1533 and NGC 1543, -- belonging to the Dorado group. Our spectral data reveal asymmetric decoupled kinematics of the stars and ionised gas in these barred lenticular galaxies that give evidences for external origin of the gas in the rings. We have calculated the star formation rates in the rings by using the ultraviolet fluxes of the rings corrected for the foreground and intrinsic absorption; and we have estimated parameters of the stellar populations in the inner parts of the galaxies confirming that they are old -- except the nucleus of NGC 1543, which demonstrates signatures of re-juvenation less than 5 Gyr ago.

The propagation of very-high-energy gamma-rays (VHEGRs) in the extragalactic space offers the opportunity to study astrophysical phenomena not reproducible in laboratories. In particular, the deviation from predictions of the observed photon flux from distant sources at the GeV energy scale still represents an open problem. Commonly, this deviation is interpreted as the result of the deflection out of the line of sight of the source of the cascade-produced charged leptons by weak magnetic fields present in the intergalactic medium (IGM). However, plasma instabilities could have an effect on the energy- and momentum-distribution of the secondary electrons and positrons, modifying the development of electromagnetic cascades. In this work, we study the influence of plasma instabilities on the energy spectrum of electromagnetic cascades through a parametric study, performed with the Monte Carlo code CRPropa. We parameterize plasma instabilities with an energy loss length normalisation $\lambda_0$ and a power law index $\alpha$ of its electron/positron energy dependence. We simulate photon spectra at Earth for different blazar scenarios and find that plasma instabilities can reproduce the suppression in the GeV-photon flux of real astrophysical sources, such as 1ES 0229+200, when the energy loss length of electrons/positrons at 1.0 TeV is $\lambda_0 \simeq 100\,\text{kpc}$ and $\alpha\simeq0$. The energy fraction lost by the secondary electron pairs due to the instability is estimated to be about $1\%$ over the typical interaction length of Inverse Compton scattering for these parameter values.

Observed evolution of the total mass distribution with redshift is crucial to testing galaxy evolution theories. To measure the total mass distribution, strong gravitational lenses complement the resolved dynamical observations currently limited to $z \lesssim 0.5$. Here we present the lens models for a pilot sample of seven galaxy-scale lenses from the ASTRO3D Galaxy Evolution with Lenses (AGEL) survey. The AGEL lenses, modeled using HST/WFC3-F140W images with Gravitational Lens Efficient Explorer (GLEE) software, have deflector redshifts between $0.3 < z_{\rm defl} < 0.9$. Assuming a power-law density profile with slope $\gamma$, we measure the total density profile for the deflector galaxies via lens modeling. We also measure the stellar velocity dispersions ($\sigma_{\rm obs}$) for four lenses and obtain $\sigma_{\rm obs}$ from SDSS-BOSS for the remaining lenses to test our lens models by comparing observed and model-predicted velocity dispersions. For the seven AGEL lenses, we measure an average density profile slope of $-1.95 \pm 0.09$ and a $\gamma$--$z$ relation that does not evolve with redshift at $z<1$. Although our result is consistent with some observations and simulations, it differs from other studies at $z<1$ that suggest the $\gamma$--$z$ relation evolves with redshift. The apparent conflicts among observations and simulations may be due to a combination of 1) systematics in the lensing and dynamical modeling; 2) challenges in comparing observations with simulations; and 3) assuming a simple power-law for the total mass distribution. By providing more lenses at $z_{\rm defl} > 0.5$, the AGEL survey will provide stronger constraints on whether the mass profiles evolve with redshift as predicted by current theoretical models.

Flares from magnetically active dwarf stars should produce relativistic particles capable of creating gamma-rays. So far, the only isolated main sequence star besides the Sun to have been detected in gamma-rays is TVLM 513-46546. Detecting gamma-ray flares from more dwarf stars can improve our understanding of their magnetospheric properties, and could also indicate a diminished likelihood of their planets' habitability. In this work, we stack data from the Fermi Gamma-ray Space Telescope during a large number of events identified from optical and X-ray flare surveys. We report an upper limit of gamma-ray emission from the population of flare stars. Stacking results towards control positions are consistent with a non-detection. We compare these results to observed Solar gamma-ray flares and against a model of emission from neutral pion decay. The upper limit is consistent with Solar flares when scaled to the flare energies and distances of the target stars. As with Solar flares, the neutral pion decay mechanism for gamma-ray production is also consistent with these results.

We investigate the star formation occurring in the Planck Galactic cold clump PGCC 120.69+2.66. Near-infrared JHKs images and K-band spectroscopy obtained with NOTCam at the Nordic Optical Telescope complemented with archive data are used to study the stellar content. In addition, millimetre line CO and CS spectra were obtained with the Onsala 20 m telescope, and sub-millimetre continuum SCUBA archive data are used to characterise the host molecular cloud. We identify a molecular cloud core traced by CO and CS emission at a distance of 1.1 kpc. In the region studied, we identify 5 submm continuum cores. Embedded in and around these dense submm cores, we find 38 young stellar objects, classified as 9 Class I, 8 Class II, and 21 near-IR excess or variability sources, accompanied by bipolar nebulosities and signs of protostellar jets. Furthermore, a very bright and reddened source is found towards this molecular cloud core. Even though its location appears to suggest its association to the star formation region, its infrared spectral type is compatible with a red supergiant, hidden behind 36 mag of visual extinction.

Magnetars are potential energy sources or central engines for numerous transient phenomena in the universe. How newborn magnetars evolve in different environments remains an open question. Based on both observed and candidate magnetars, it is found that the periods of all magnetars or candidates appear as a bimodal distribution, and are defined as the ``long-P'' and ``short-P'' magnetar sub-classes, respectively. We find that for the ``short-P'' sub-class of magnetars, the $\dot{P}$ values also appear as a bimodal distribution, and therefore can be classified as ``high-$\dot{P}$ short-P'' and ``low-$\dot{P}$ short-P'' magnetar sub-classes. In this paper, we use Monte Carlo simulations to generate synthetic magnetar populations and investigate the evolution of the ``high-$\dot{P}$ short-P'' and ``low-$\dot{P}$ short-P'' magnetar sub-classes by considering both the magnetar spin and inclination, as well as the decay of their magnetic field within their evolution in both vacuum and plasma-filled magnetospheres. We find that the magnetar evolution is dependent on both spin and magnetic field, but seems to be insensitive to inclination evolution and magnetospheric environment for the ``high-$\dot{P}$ short-P'' sub-class. In comparison for the case of ``high-$\dot{P}$ short-P'', the magnetar evolution is dependent on spin, magnetic field, and inclination evolution, as well as the magnetospheric environment. The best evolution model should be the case of inclination evolution in vacuum with a small value of $\overline{\mathrm{FOM}}$. The differences in the best-fit parameters also suggest that the ``high-$\dot{P}$ short-P'' and ``low-$\dot{P}$ short-P'' magnetar sub-classes may be tracking with different evolution channels.

We point out that the rotation angle $\beta$ of cosmic birefringence, which is a recently reported parity-violating signal in the cosmic microwave background (CMB), has a phase ambiguity of $n\pi \,(n\in\mathbb{Z})$. This ambiguity has a significant impact on the interpretation of the origin of cosmic birefringence. Assuming an axion-like particle as the origin of cosmic birefringence, this ambiguity can be partly broken by the anisotropic cosmic birefringence and the shape of the CMB angular power spectra. We also discuss constraints on $\beta$ from existing experimental results.

Discs in long-period eclipsing binary systems are rare and can lead to extraordinary eclipsing events. ZTF J185259.31+124955.2 was identified as a candidate disc-eclipsing system through a continuing search programme of ZTF variables with a near-IR excess in the WISE data. Examination of the combined ZTF and ATLAS photometry shows seven eclipses since 2017 with depths of 0\fm34 in all bands on a period of $289.57\pm0.09$\,d. The eclipse width is $\sim 40$\,d but this and the profile evolve over time. Comparison with library spectra shows that the spectral energy distribution from the available photometry is consistent with an early K-type giant, and fitting black-body profiles suggests $T_{eff} \sim 4000$\,K for the stellar component, with a cool component having $T_{eff} < 500$\,K. The reddening and distance, and hence the luminosity place the star within the giant branch. The most likely scenario is that the system is in a state of rapid evolution following Case B/C mass transfer into an extended disc around an unseen companion.

Aims. We explore machine learning techniques to forecast star formation rate, stellar mass, and metallicity across galaxies with redshifts ranging from 0.01 to 0.3. Methods. Leveraging CatBoost and deep learning architectures, we utilize multiband optical and infrared photometric data from SDSS and AllWISE, trained on the SDSS MPA-JHU DR8 catalogue. Results. Our study demonstrates the potential of machine learning in accurately predicting galaxy properties solely from photometric data. We achieve minimised root mean square errors, specifically employing the CatBoost model. For star formation rate prediction, we attain a value of RMSESFR = 0.336 dex, while for stellar mass prediction, the error is reduced to RMSESM = 0.206 dex. Additionally, our model yields a metallicity prediction of RMSEmetallicity = 0.097 dex. Conclusions. These findings underscore the significance of automated methodologies in efficiently estimating critical galaxy properties, amid the exponential growth of multi-wavelength astronomy data. Future research may focus on refining machine learning models and expanding datasets for even more accurate predictions.

The magnetic geometry of the solar atmosphere, combined with projection effects, makes it difficult to accurately map the propagation of ubiquitous waves in fibrillar structures. These waves are of interest due to their ability to carry energy into the chromosphere and deposit it through damping and dissipation mechanisms. To this end, the Interferometric Bidimensional Spectrometer (IBIS) at the Dunn Solar Telescope was employed to capture high resolution H$\alpha$ spectral scans of a sunspot, with the transverse oscillations of a prominent super-penumbral fibril examined in depth. The oscillations are re-projected from the helioprojective-cartesian frame to a new frame of reference oriented along the average fibril axis through non-linear force-free field extrapolations. The fibril was found to be carrying an elliptically polarised, propagating kink oscillation with a period of $430$ s and a phase velocity of $69\pm4$ km s$^{-1}$. The oscillation is damped as it propagates away from the sunspot with a damping length of approximately $9.2$ Mm, resulting in the energy flux decreasing at a rate on the order of $460$ W m$^{-2}$/Mm. The H$\alpha$ line width is examined and found to increase with distance from the sunspot; a potential sign of a temperature increase. Different linear and non-linear mechanisms are investigated for the damping of the wave energy flux, but a first-order approximation of their combined effects is insufficient to recreate the observed damping length by a factor of at least $3$. It is anticipated that the re-projection methodology demonstrated in this study will aid with future studies of transverse waves within fibrillar structures.

Detecting protoplanets during their formation stage is an important but elusive goal of modern astronomy. Kinematic detections via the spiral wakes in the gaseous disc are a promising avenue to achieve this goal. We aim to test the applicability to observations in the low and intermediate planet mass regimes of a commonly used semi-analytical model for planet induced spiral waves. In contrast with previous works which proposed to use the semi-analytical model to interpret observations, in this study we analyse for the first time both the structure of the velocity and density perturbations. We run a set of FARGO3D hydrodynamic simulations and compare them with the output of the semi-analytic model in the code wakeflow, which is obtained by solving Burgers' equation using the simulations as an initial condition. We find that the velocity field derived from the analytic theory is discontinuous at the interface between the linear and nonlinear regions. After 0.2 r$_p$ from the planet, the behaviour of the velocity field closely follows that of the density perturbations. In the low mass limit, the analytical model is in qualitative agreement with the simulations, although it underestimates the azimuthal width and the amplitude of the perturbations, predicting a stronger decay but a slower azimuthal advance of the shock fronts. In the intermediate regime, the discrepancy increases, resulting in a different pitch angle between the spirals of the simulations and the analytic model. The implementation of a fitting procedure based on the minimisation of intensity residuals is bound to fail due to the deviation in pitch angle between the analytic model and the simulations. In order to apply this model to observations, it needs to be revisited accounting also for higher planet masses.

We conducted a search for HI emission of the gas-rich galaxies in the Vela region ($260^{\circ} \leq \ell \leq 290^{\circ}, -2^{\circ} \leq b \leq 1^{\circ}$) to explore the Vela Supercluster (VSCL) at $V_\mathrm{hel} \sim 18000$ km s$^{-1}$, largely obscured by Galactic dust. Within the mostly RFI-free band ($250 < V_\mathrm{hel} < 25000$ km s$^{-1}$) of MeerKAT, the analysis focuses on $157$ hexagonally distributed pointings extracted from the SARAO MeerKAT Galactic Plane Survey located in the Vela region (Vela$-$SMGPS). These were combined into 10 contiguous mosaics, covering a ${\sim}90$ deg$^2$ area. Among the $843$ HI detected sources, 39 were previously discovered in the Parkes HIZOA survey ($V_\mathrm{hel} < 12000$ km s$^{-1}$; rms $\sim 6$ mJy beam$^{-1}$). With the improved rms level of the Vela$-$SMGPS, i.e., $0.29 - 0.56$ mJy beam$^{-1}$, our study unveils nearly 12 times more detections (471 candidates) in that same velocity range. We furthermore could identify $187$ galaxy candidates with an HI mass limit reaching $\log (M_{\rm HI}/\rm M_{\odot}) = 9.44$ in the VSCL velocity range $V_\mathrm{hel} \sim 19500 \pm 3500$ km s$^{-1}$. We find indications of two wall-like overdensities that confirm the original suspicion that these walls intersect at low latitudes around longitudes of $\ell \sim 272^{\circ} - 278^{\circ}$. We also find a strong signature most likely associated with the Hydra/Antlia extension and evidence of a previously unknown narrow filament at $V_\mathrm{hel} \sim 12000$ km s$^{-1}$. This paper demonstrates the efficiency of systematic HI surveys with the SKA precursor MeerKAT, even in the most obscured part of the Zone of Avoidance (ZOA).

The Large High Altitude Airshower Array (LHAASO) has detected very high energy gamma rays from the LINER galaxy NGC 4278, which has a low luminosity active galactic nucleus, and symmetric mildly relativistic S-shaped twin jets detected by radio observations. Few low-luminosity active galactic nuclei are detected in gamma rays due to their faintness. Earlier, several radio-emitting components were detected in the jets of NGC 4278. We model their radio emission with synchrotron emission of ultra-relativistic electrons to estimate the strength of the magnetic field inside these components within a time-dependent framework after including the ages of the different components. We show that the synchrotron and synchrotron self-Compton emission by these components cannot explain the Swift X-ray data detected from NGC 4278 and the LHAASO gamma-ray data associated with NGC 4278. We suggest that a separate component in one of the jets is responsible for the high energy emission whose age, size, magnetic field and the spectrum of the ultra-relativistic electrons inside it have been estimated after fitting the multi-wavelength data of NGC 4278 with the sum of the spectral energy distributions from the radio components and the high energy component.

In light of the discovery of the long-period radio pulsar PSR J0901-4046, it is interesting to revisit a question about how the magnetized neutron star slows down its rotation. In the case of a weak or liquid outer crust, the mechanism of spin-down becomes unclear because the braking stress cannot then be transmitted from the surface to the main bulk of the star. We show that even if the outer crust does not withstand the surface electromagnetic forces creating the braking torque, the stellar spin-down does not stop, and the matter rearranges so that the necessary electromagnetic forces form in more deep and rigid layers capable of withstanding these forces. The spin-down rate remains the same and corresponds to the transformation of the rotational energy of the neutron star into the energy of the generated relativistic electron-positron plasma. The solid iron surface of ultrastrongly magnetized PSR J0901-4046 appears not to be yielding and withstands the braking stress without breaking.

A direct consequence of Faraday rotation is that the polarized radio sky does not resemble the total intensity sky at long wavelengths. We analyze G137+7, which is undetectable in total intensity but appears as a depolarization feature. We use the first polarization maps from the Canadian Hydrogen Intensity Mapping Experiment. Our $400-729$ MHz bandwidth and angular resolution, $17'$ to $30'$, allow us to use Faraday synthesis to analyze the polarization structure. In polarized intensity and polarization angle maps, we find a "tail" extending $10^\circ$ from the "head" and designate the combined object the "tadpole". Similar polarization angles, distinct from the background, indicate that the head and tail are physically associated. The head appears as a depolarized ring in single channels, but wideband observations show that it is a Faraday rotation feature. Our investigations of H I and H$\alpha$ find no connections to the tadpole. The tail suggests motion of either the gas or an ionizing star through the ISM; the B2(e) star HD 20336 is a candidate. While the head features a coherent, $\sim -8$ rad m$^2$ Faraday depth, Faraday synthesis also identifies multiple components in both the head and tail. We verify the locations of the components in the spectra using QU fitting. Our results show that $\sim$octave-bandwidth Faraday rotation observations at $\sim 600$ MHz are sensitive to low-density ionized or partially-ionized gas which is undetectable in other tracers.

Millisecond pulsars (MSPs) are abundant in globular clusters (GCs), which offer favorable environments for their creation. While the advent of recent, powerful facilities led to a rapid increase in MSP discoveries in GCs through pulsation searches, detection biases persist. In this work, we investigate the ability of current and future detections in GCs to constrain the parameters of the MSP population in GCs through a careful study of their luminosity function. Parameters of interest are the number of MSPs hosted by a GC, as well as the mean and the width of their luminosity function, which are typically affected by large uncertainties. While, as we show, likelihood-based studies can lead to ill-behaved posterior on the size of the MSP population, we introduce a novel, likelihood-free analysis, based on Marginal Neural Ratio Estimation, which consistently produces well-behaved posteriors. We focus on the GC Terzan 5, which currently counts 48 detected MSPs. We find that about 158 MSPs should be hosted in this GC, but the uncertainty on this number remains large. We explore the performance of our new method on simulated Terzan 5-like datasets mimicking possible future observational outcomes. We find that significant improvement on the posteriors can be obtained by adding a reliable measurement of the diffuse radio emission of the GC to the analysis or by improving the detection threshold of current radio pulsation surveys by at least a factor two.

Despite recent progress, the question of what regulates the star formation efficiency in galaxies remains one of the most debated problems in astrophysics. According to the dominant picture, star formation (SF) is regulated by turbulence and feedback, and the SFE is 1-2% per local free-fall time. In an alternate scenario, the SF rate in galactic disks is linearly proportional to the mass of dense gas above a critical density threshold. We aim to discriminate between these two pictures thanks to high-resolution observations tracing dense gas and young stellar objects (YSOs) for a comprehensive sample of 49 nearby massive SF complexes out to d < 3 kpc in the Galactic disk. We use data from CAFFEINE, a 350/450 $\mu$m survey with APEX/ArTéMiS of the densest portions of all southern molecular clouds, in combination with Herschel data to produce column density maps at 8" resolution. Our maps are free of saturation and resolve the structure of dense gas and the typical 0.1 pc width of molecular filaments at 3 kpc, which is impossible with Herschel data alone. Coupled with SFR estimates derived from Spitzer observations of the YSO content of the same clouds, this allows us to study the dependence of the SFE with density in the CAFFEINE clouds. We also combine our findings with existing SFE measurements in nearby clouds to extend our analysis down to lower column densities. Our results suggest that the SFE does not increase with density above the critical threshold and support a scenario in which the SFE in dense gas is approximately constant. However, the SFE measurements traced by Class I YSOs in nearby clouds are more inconclusive, since they are consistent with both the presence of a density threshold and a dependence on density above the threshold. Overall, we suggest that the SFE in dense gas is primarily governed by the physics of filament fragmentation into protostellar cores.

The non-gravitational interaction between the dark components of the Universe could lead to the variation of dark matter energy density standard evolution law. When we assume this scenario, the dark matter energy density follows $\rho_{dm}\sim(1+z)^{3 + \epsilon(z)}$ (where $\epsilon(z)=0$ the standard law is recovered). In this paper, we perform a Bayesian analysis to test three parameterizations for $\epsilon(z)$, namely: $\epsilon(z)=\epsilon_0$, $\epsilon(z)=\epsilon_0 + \epsilon_1\frac{z}{1+z}$ and $\epsilon(z)=\epsilon_0 + \epsilon_1\frac{z(1+z)}{1+z^2}$, where the first one is motivated through the fundamental grounds and the others are on the phenomenological ones. Through the Gaussian process regression, our method uses galaxy cluster gas mass fraction measurements, SNe Ia observations, Cosmic Chronometers, and BAO data. No specific cosmological model is considered. In all possibilities analyzed, the standard evolution law ($\epsilon(z)=0$) is within $2\sigma$ c.l. The investigated cases generally indicated scenarios of inconclusive or weak evidence toward the simplest model from the Bayesian standpoint.

We obtain the largest catalog of multi-mode $\delta$ Sct stars in the northern sky to date using the Zwicky Transient Facility (ZTF) Data Release 20 (DR20). The catalog includes 2254 objects, of which 2181 are new to our study. Among these multi-mode $\delta$ Sct stars, 2142 objects are double-mode $\delta$ Sct, while 109 objects are triple-mode $\delta$ Sct and 3 are quadruple-mode $\delta$ Sct. By analyzing the light curves in the $r$ and $g$ bands of the ZTF, we determine the basic parameters of multi-mode $\delta$ Sct stars, including the periods and amplitudes. Periods are checked by comparison with the OGLE catalog of double-mode $\delta$ Sct stars. On the Petersen diagram, multi-mode $\delta$ Sct stars form six sequences. We find that in Galactic coordinates, the periods of 1O/F double-mode $\delta$ Sct stars at high latitudes are shorter than those of 1O/F double-mode $\delta$ Sct stars in the disk, due to metallicity variations. In the future, our catalog can be used to establish the period--luminosity relation and the period--metallicity relation of double-mode $\delta$ Sct stars, and to study the Galactic structure.

Modern space missions with uncrewed spacecraft require robust trajectory design to connect multiple chaotic orbits by small controls. To address this issue, we propose a control scheme to design robust trajectories by leveraging a geometrical structure in chaotic zones, known as a {\it lobe}. Our scheme shows that appropriately selected lobes reveal possible paths to traverse chaotic zones in a short time. The effectiveness of our method is demonstrated through trajectory design in both the standard map and Hill's equation.

Mathematicians have been proposing for sometimes that Monge-Ampère equation, a nonlinear generalization of the Poisson equation, where trace of the Hessian is replaced by its determinant, provides an alternative non-relativistic description of gravity. Monge-Ampère equation is affine invariant, has rich geometric properties, connects to optimal transport theory, and remains bounded at short distances. Monge-Ampère gravity, that uses a slightly different form of the Monge-Ampère equation, naturally emerges through the application of large-deviation principle to a Brownian system of indistinguishable and independent particles. In this work we provide a physical formulation of this mathematical model, study its theoretical viability and confront it with observations. We show that Monge-Ampère gravity cannot replace the Newtonian gravity as it does not withstand the solar-system test. We then show that Monge-Ampère gravity can describe a scalar field, often evoked in modified theories of gravity such as Galileons. We show that Monge-Ampère gravity, as a nonlinear model of a new scalar field, is screened at short distances, and behaves differently from Newtonian gravity above galactic scales but approaches it asymptotically. Finally, we write a relativistic Lagrangian for Monge-Ampère gravity in flat space time, which is the field equation of a sum of the Lagrangians of all Galileons. We also show how the Monge-Ampère equation can be obtained from the fully covariant Lagrangian of quartic Galileon in the static limit. The connection between optimal transport theory and modified theories of gravity with second-order field equations, unravelled here, remains a promising domain to further explore.

Research-based active learning approaches are critical for the teaching and learning of undergraduate STEM majors. Course-based undergraduate research experiences (CUREs) are becoming more commonplace in traditional, in-person academic environments, but have only just started to be utilized in online education. Online education has been shown to create accessible pathways to knowledge for individuals from nontraditional student backgrounds, and increasing the diversity of STEM fields has been identified as a priority for future generations of scientists and engineers. We developed and instructed a rigorous, six-week curriculum on the topic of observational astronomy, dedicated to educating second year online astronomy students in practices and techniques for astronomical research. Throughout the course, the students learned about telescopes, the atmosphere, filter systems, adaptive optics systems, astronomical catalogs, and image viewing and processing tools. We developed a survey informed by previous research validated assessments aimed to evaluate course feedback, course impact, student self-efficacy, student science identity and community values, and student sense of belonging. The survey was administered at the conclusion of the course to all eleven students yielding eight total responses. Although preliminary, the results of our analysis indicate that student confidence in utilizing the tools and skills taught in the course was significant. Students also felt a great sense of belonging to the astronomy community and increased confidence in conducting astronomical research in the future.

Certain measurements in celestial mechanics necessitate having the origin O of a Cartesian coordinate system (CCS) coincide with a point mass. For the two and three body problems we show mathematical inadequacies in Newton's celestial mechanics equations (NCME) when the origin of a coordinate system coincides with a point mass. A certain system of equations of relative differences implied by NCME is free of these inadequacies and is invariant with respect to any CCS translation. A new constant of motion is derived for the relative system. It shows that the universe of relative differences of the $N$-body problem is ``restless''.