bluuebunny/crossref_metadata_2025_split huggingface dataset:
Red supergiant candidates for multimessenger monitoring of the next Galactic supernova
Authors: Healy Sarah , Horiuchi Shunsaku , Colomer Molla Marta , Milisavljevic Dan , Tseng Jeff , Bergin Faith , Weil Kathryn , Tanaka Masaomi , Otero Sebastián 
Published: March 2024

ABSTRACT
We compile a catalogue of 578 highly probable and 62 likely red supergiants (RSGs) of the Milky Way, which represents the largest list of Galactic RSG candidates designed for continuous follow-up efforts to date. We match distances measured by Gaia DR3, 2MASS photometry, and a 3D Galactic dust map to obtain luminous bright late-type stars. Determining the stars’ bolometric luminosities and effective temperatures, we compare to Geneva stellar evolution tracks to determine likely RSG candidates, and quantify contamination using a catalogue of Galactic AGB in the same luminosity-temperature space. We add details for common or interesting characteristics of RSG, such as multistar system membership, variability, and classification as a runaway. As potential future core-collapse supernova progenitors, we study the ability of the catalogue to inform the Supernova Early Warning System (SNEWS) coincidence network made to automate pointing, and show that for 3D position estimates made possible by neutrinos, the number of progenitor candidates can be significantly reduced, improving our ability to observe the progenitor pre-explosion and the early phases of core-collapse supernovae.
Flares during eclipses of high-mass X-ray binary systems Vela X-1, 4U 1700−37, and LMC X-4
Authors: Rikame Ketan , Paul Biswajit , Sharma Rahul , Jithesh V , Paul K T 
Published: March 2024

ABSTRACT
In eclipsing X-ray binary systems, the direct X-ray emission is blocked by the companion star during the eclipse. We observe only reprocessed emission that contains clues about the environment of the compact object and its chemical composition, ionization levels, etc. We have found flares in some X-ray binaries during their eclipses. The study of eclipse flares provides additional clues regarding the size of the reprocessing region and helps distinguish between different components of the X-ray spectrum observed during the eclipse. In the archival data, we searched for flares during eclipses of high-mass X-ray binaries and found flares in three sources: Vela X-1, LMC X-4, and 4U 1700−37. Comparing spectral properties of the eclipse flare and non-flare data, we found changes in the power-law photon index in all three sources and multiple emission lines in Vela X-1 and 4U 1700-37. The fluxes of prominent emission lines showed a similar increase as the overall X-ray flux during the eclipse flare, suggesting the lines originate in the binary environment and not in the interstellar medium. We also observed a soft excess in 4U 1700-37 that remains unchanged during both eclipse flare and non-flare states. Our analysis suggests that this emission originates from the extremely thin shell of the stellar wind surrounding the photosphere of its companion star. The detection of short (100–200 s) count-rate doubling time-scale in 4U 1700−37 and LMC X-4 indicates that the eclipse reprocessing occurs in a region larger than, but comparable to the size of the companion star.
Age of Geminids derived from the statistics of meteoroid orbits
Authors: Milanov D V , Shaidulin V S , Rusakov A S , Veselova A V 
Published: March 2024

ABSTRACT
Statistical analysis of samples of the orbits of celestial bodies is complicated by the fact that the Keplerian orbit is a multidimensional object, the coordinate representation of which non-linearly depends on the choice of orbital elements. In this work, using the construction of the Fréchet mean, concepts of mean orbit and dispersion of the orbit family are introduced, consistent with the distance function on the orbit set. The introduced statistical characteristics serve as analogues of sample mean and variance of a one-dimensional random variable. Exact formulas for calculating the elements of mean orbits and dispersion quantities with respect to two metrics on the orbit space are derived. For a large sample of meteoroid orbits from the Geminid stream, numerical simulations of orbit evolution over 20 000 yr in the past were conducted. By analysing the dependency of statistical characteristics on time, estimates for the age of the stream and the gas outflow velocity are obtained under the assumption of the birth of the Geminids due to the rapid destruction of the cometary nucleus. The estimate of the age of the stream lies in the interval from 1200 to 2400 yr, and the speed of gas outflow at perihelion should have been more than 1.2 km s−1.
Cosmic-ray induced ionization rates and non-thermal emissions from nuclei of starburst galaxies
Authors: Phan Vo Hong Minh , Peretti Enrico , Cristofari Pierre , Gusdorf Antoine , Mertsch Philipp 
Published: March 2024

ABSTRACT
Cosmic rays are the only agent capable of ionizing the interior of dense molecular clouds and, thus, they are believed to play an essential role in determining the physical and chemical evolution of star-forming regions. In this work, we aim to study cosmic-ray induced ionization rates in starburst environments using non-thermal emissions of cosmic rays from starburst nuclei. To this end, we first revisit cosmic-ray models, which could explain data of non-thermal emissions from radio to X-ray and gamma-ray from nuclei of three prototypical starburst galaxies NGC 253, M82, and Arp 220. These models are then applied to predict ionization rates in starburst environments, which gives values around 10−14 s−1. Such a high value of the ionization rate, which is 2 to 3 orders of magnitude higher than the typical values found in the Milky Way, is probably due to relatively high rates of supernova explosions occurring within the nuclei of these starburst galaxies. We also discuss in more detail the case of NGC 253, where our predicted ionization rate is found to be, in most cases, a few times smaller than the values inferred from molecular line observations of clouds in the starburst nucleus. The general framework provided in this work illustrates how the use of non-thermal emission data could help to provide more insights into ionization rates or, more generally, cosmic-ray impact in starburst environments.
Probing the physics of reionization using kinematic Sunyaev–Zeldovich power spectrum from current and upcoming cosmic microwave background surveys
Authors: Jain Divesh , Choudhury Tirthankar Roy , Raghunathan Srinivasan , Mukherjee Suvodip 
Published: March 2024

ABSTRACT
The patchiness in the reionization process alters the statistics of cosmic microwave background (CMB), with the kinematic Sunyaev–Zeldovich (kSZ) effect in the CMB temperature power spectrum being a notable consequence. In this work, we aim to explore the potential of future kSZ power spectrum measurements in inferring the details of the reionization process. In this pursuit, we capitalize on the recent developments in foreground mitigation techniques using the Cross-Internal Linear Combination (Cross-ILC) technique, which enables robust detection of the kSZ power spectrum with signal-to-noise ratio roughly 20σ–30σ in this decade by South pole Telescope (SPT-3G) and Simons Observatory (SO); and ≥80σ by CMB-S4 – substantially improving on the recent evidence for kSZ binned at ℓ = 3000 using SPT-SZ + SPTpol surveys. We use a fiducial kSZ power spectrum along with realistic error bars expected from the above technique for SPT-3G, SO, and CMB-S4 to constrain the parameter space for a physical model of reionization. We find that with the improved error bars it will be possible to place stringent constraints on reionization using solely the Cross-ILC recovered SPT-3G kSZ without imposing any prior on τ in the Bayesian inference. Notably, high-fidelity kSZ measurements from CMB-S4 coupled with τ measurements through LiteBIRD will enable unprecedented constraint on the midpoint of reionization with an error bar of ∼0.25 and the duration of reionization with an error bar at ∼0.21 exclusively using CMB data. This study highlights the need to capture kSZ power spectrum on a broad range of multipoles to gain insights into the inhomogeneous reionization era.
The long-lasting effect of X-ray pre-heating in the post-reionization intergalactic medium
Authors: Montero-Camacho Paulo , Zhang Yao , Mao Yi 
Published: March 2024

ABSTRACT
X-ray photons can penetrate deep into the intergalactic medium (IGM), leading to pre-heating of the IGM prior to cosmic reionization. X-ray pre-heating wipes out some of the small-scale structures that would otherwise be present prior to the passage of an ionization front. Accurate modelling of the small-scale structure is vital to the post-reionization IGM, since the small-scale structure is ultimately the dominant source of long-lasting relics from hydrogen reionization. However, the precise impact of X-ray pre-heating in the fossils from hydrogen reionization is highly uncertain. In this work, we explore and establish for the first time, the long-lasting impact of X-ray pre-heating in the post-reionization IGM via hydrodynamic simulations with high-mass resolution. We find that the addition of X-ray pre-heating astrophysics leads to an overall lesser impact of the effect of inhomogeneous reionization in the Lyα forest – depending on specific X-ray prescription – at low redshifts (z ∼ 2) with respect to a model with no X-ray pre-heating. However, at high redshifts (z ∼ 4), our results indicate a strengthening of the relics of reionization in the Lyα forest because the IGM becomes more transparent compared to the scenario with no pre-heating. Thus, the absence of X-ray pre-heating in Lyα modelling can lead to a biased inference of cosmological parameters. Nevertheless, optimistically, the inclusion of X-ray pre-heating emerges as a promising novel avenue to probe the astrophysics of cosmic dawn.
Homogeneous metallicities for 14 old LMC globular clusters based on their fundamental mode RR Lyrae stars
Authors: Sarajedini Ata 
Published: March 2024

ABSTRACT
We present the first internally consistent set of [Fe/H] values for 14 of the 15 old globular clusters in the Large Magellanic Cloud (LMC). We make use of periods and amplitudes of fundamental mode (ab-type) RR Lyrae stars in the vicinity of these LMC clusters, mostly taken from the Optical Gravitational Lensing Experiment (OGLE) data base, in order to calculate metallicities for the clusters. Our data set contains a total of 417 ab-type cluster RR Lyrae stars (289 from OGLE and the rest from the literature) and yields a set of homogeneous metallicities for 14 old LMC globular clusters all on the Zinn and West scale. No previously published work contains metallicities for as many of the old LMC globular clusters as presented herein. An analysis of a subset of our abundances compared with seven other metallicity studies in the peer-reviewed literature indicates very little overall agreement between these [Fe/H] values suggesting that significantly more effort needs to be devoted to measuring internally consistent [Fe/H]s for the old LMC globular clusters.
Unveiling the hidden Universe with JWST: the contribution of dust-obscured galaxies to the stellar mass function at z ~ 3 – 8
Authors: Gottumukkala R , Barrufet L , Oesch P A , Weibel A , Allen N , Alcalde Pampliega B , Nelson E J , Williams C C , Brammer G , Fudamoto Y , González V , Heintz K E , Illingworth G , Magee D , Naidu R P , Shuntov M , Stefanon M , Toft S , Valentino F , Xiao M 
Published: March 2024

ABSTRACT
With the advent of JWST, we can probe the rest-frame optical emission of galaxies at $z\gt 3$ with high sensitivity and spatial resolution, making it possible to accurately characterize red, optically faint galaxies and thus move towards a more complete census of the galaxy population at high redshifts. To this end, we present a sample of 148 massive, dusty galaxies from the JWST/Cosmic Evolution Early Release Science survey, colour-selected using solely JWST bands. With deep JWST/NIRCam data from 1.15 to 4.44 $\mu$m and ancillary HST/ACS and WFC3 data, we determine the physical properties of our sample using spectral energy distribution fitting with bagpipes. We demonstrate that our selection method efficiently identifies massive ($\mathrm{\langle \log {\it M}_\star /M_\odot \rangle \sim 10}$) and dusty ($\mathrm{\langle {\it A}_V\rangle \sim 2.7\ mag}$) sources, with a majority at $z\,\gt\, 3$ and predominantly lying on the galaxy main sequence. The main results of this work are the stellar mass functions (SMFs) of red, optically faint galaxies from redshifts between $3\,\lt\, z\,\lt\, 8$: these galaxies make up a significant relative fraction of the pre-JWST total SMF at $3\,\lt\, z\,\lt\, 4$ and $4\,\lt\, z\,\lt\, 6$, and dominate the high-mass end of the pre-JWST SMF at $6\,\lt\, z\,\lt \,8$, suggesting that our census of the galaxy population needs amendment at these epochs. While larger areas need to be surveyed in the future, our results suggest already that the integrated stellar mass density at $\mathrm{\log {\it M}_\star /M_\odot \ge 9.25}$ may have been underestimated in pre-JWST studies by up to $\sim$15–20% at $z\sim 3{\!-\!}6$, and up to $\sim$45% at $z\sim 6{\!-\!}8$, indicating the rapid onset of obscured stellar mass assembly in the early Universe.
21 cm intensity mapping cross-correlation with galaxy surveys: Current and forecasted cosmological parameters estimation for the SKAO
Authors: Berti Maria , Spinelli Marta , Viel Matteo 
Published: March 2024

ABSTRACT
We present a comprehensive set of forecasts for the cross-correlation signal between 21 cm intensity mapping and galaxy redshift surveys. We focus on the data sets that will be provided by the SKAO for the 21 cm signal, DESI and Euclid for galaxy clustering. We build a likelihood which takes into account the effect of the beam for the radio observations, the Alcock–Paczynski effect, a simple parametrization of astrophysical nuisances, and fully exploit the tomographic power of such observations in the range z = 0.7–1.8 at linear and mildly non-linear scales (k &lt; 0.25h Mpc−1). The forecasted constraints, obtained with Monte Carlo Markov Chains techniques in a Bayesian framework, in terms of the six base parameters of the standard ΛCDM model, are promising. The predicted signal-to-noise ratio for the cross-correlation can reach ∼50 for z ∼ 1 and k ∼ 0.1h Mpc−1. When the cross-correlation signal is combined with current Cosmic Microwave Background (CMB) data from Planck, the error bar on $\Omega _{\rm c}\, h^2$ and H0 is reduced by factors 3 and 6, respectively, compared to CMB only data, due to the measurement of matter clustering provided by the two observables. The cross-correlation signal has a constraining power that is comparable to the autocorrelation one and combining all the clustering measurements a sub-per cent error bar of 0.33 per cent on H0 can be achieved, which is about a factor 2 better than CMB only measurements. Finally, as a proof of concept, we test the full pipeline on the real data measured by the MeerKat collaboration (Cunnington et al. 2022) presenting some (weak) constraints on cosmological parameters.
Polymer amide as a source of the cosmic 6.2 μm emission and absorption
Authors: McGeoch Julie E M , McGeoch Malcolm W 
Published: March 2024

ABSTRACT
Cosmic infrared emission and absorption spectra often carry a well-defined and invariant 6.2 $\mu \rm m$ band that has been proposed to emanate from very small dust grains that may carry polyaromatic hydrocarbons. Hemoglycin, a well-defined polymer of glycine that also contains iron, has been found in meteorites of the primordial CV3 class and therefore originated in the solar protoplanetary disc. Here, we suggest that the polymer hemoglycin should also be considered as a source of the cosmic 6.2 $\mu{\rm m}$ emission and absorption. In quantum calculations, the principal amide I infrared absorption band of hemoglycin is centred, before splitting, at 6.0 $\mu\rm m$. Multiple hemoglycin polymers interact to split amide I into the strong (a-) band in the region of 6.2 $\mu\rm m$ and the much weaker (a+) band in the region of 5.8 $\mu\rm m$. Experimentally, these two components are seen in extracts of the Sutter’s Mill meteorite and in stromatolite ooid. The two 11-mer glycine antiparallel chains of hemoglycin have an exact structural analogue in antiparallel poly-l-lysine beta sheet crystals which in the laboratory have an (a-) absorption peak at 6.21 $\mu\rm m$. This wavelength coincidence, the demonstrated propensity of hemoglycin 4.9 nm rods to form accreting lattice structures, and its proven existence in the solar protoplanetary disc suggest that the cosmic 6.2 $\mu\rm m$ emission and absorption could be from small grains that are hemoglycin lattices or shell-like vesicles carrying internal organic molecules of various types. Calculated hemoglycin ultraviolet absorptions associated with iron in the molecule match the observed ultraviolet extinction feature at nominal 2175 Å.
Amorphous 1-propanol interstellar ice beyond its melting point
Authors: Ramachandran R , Hazarika A , Gupta S , Nag S , Meka J K , Thakur Tejender S , Yashonath S , Vishwakarma G , Chou S -L , Wu Y -J , Janardhan P , Rajasekhar B N , Bhardwaj Anil , Mason N J , Sivaraman B , Maiti Prabal K 
Published: March 2024

ABSTRACT
The recent discovery of 1-propanol (CH3CH2CH2OH) in the interstellar medium (ISM) is of tremendous interest since fatty alcohols have been proposed as constituents of proto-cell membranes. Motivated by this discovery, we present the laboratory mid-infrared (MIR) and vacuum ultraviolet (VUV) absorption spectra of 1-propanol ice under astrochemical conditions, mimicking an icy mantle on cold dust in the ISM. Both MIR and VUV spectra were recorded at ultrahigh vacuum of ∼10-9 mbar and at temperatures ranging from 10 K to sublimation. The morphology of the 1-propanol ice deposited at 10 K was amorphous. By warming the ice to temperatures of 140 K and above, with subsequent recording of IR spectra, we observe complete sublimation of 1-propanol molecules from the substrate around 170 K. No amorphous-to-crystalline phase change was observed upon warming to higher temperatures. Additionally, we observe the IR and VUV signatures of 1-propanol ice on the substrate well beyond its melting point (147 K). To the best of our knowledge, this is the first reported observation of a molecular ice staying well beyond its melting point under such conditions. This result shows that the morphology of icy mantles on ISM cold dust grains is more complex than previously thought. Our atomistic molecular dynamics simulations capture the experimental trends and shed light on the microscopic origin of this unusual phase behaviour of 1-propanol.
Machine-learning recovery of foreground wedge-removed 21-cm light cones for high-z galaxy mapping
Authors: Kennedy Jacob , Carr Jonathan Colaço , Gagnon-Hartman Samuel , Liu Adrian , Mirocha Jordan , Cui Yue 
Published: March 2024

ABSTRACT
Upcoming experiments will map the spatial distribution of the 21-cm signal over three-dimensional volumes of space during the Epoch of Reionization (EoR). Several methods have been proposed to mitigate the issue of astrophysical foreground contamination in tomographic images of the 21-cm signal, one of which involves the excision of a wedge-shaped region in cylindrical Fourier space. While this removes the k-modes most readily contaminated by foregrounds, the concurrent removal of cosmological information located within the wedge considerably distorts the structure of 21-cm images. In this study, we build upon a U-Net-based deep-learning algorithm to reconstruct foreground wedge-removed maps of the 21-cm signal, newly incorporating light-cone effects. Adopting the Square Kilometre Array as our fiducial instrument, we highlight that our U-Net recovery framework retains a reasonable level of reliability even in the face of instrumental limitations and noise. We subsequently evaluate the efficacy of recovered maps in guiding high-redshift galaxy searches and providing context to existing galaxy catalogues. This will allow for studies of how the high-redshift galaxy luminosity function varies across environments, and ultimately refine our understanding of the connection between the ionization state of the intergalactic medium and galaxies during the EoR.
A statistical analysis of over three thousand meteors and their spectra
Authors: Betzler Alberto S , Sekiguchi Takashi 
Published: March 2024

ABSTRACT
In this article, over three thousand meteor spectra recorded in Saitama, Japan, between 2018 and 2021 are analysed. We performed a principal component analysis of the intensity of the sodium and magnesium lines and the iron band of each meteor in combination with the orbital elements and the kinematic parameters such as the geocentric velocity and the initial and final altitudes to determine the relative importance of each of these variables in the composition of a meteor’s spectrum. We found that for meteor showers such as GEM, LEO, QUA, and PER, the orbital elements or kinematic parameters are important parameters that determine the intensity of these spectral lines, which could indicate the influence of gravitational and/or non-gravitational forces in distinguishing the composition or variations in the strength of the meteoroid material in each meteor shower. The normal spectral type in our sample ranges from 39.5 per cent to 96.8 per cent, corresponding to GEM and PER, respectively. The COM meteors have a similar sodium content to the components of the LEO and PER showers, suggesting a comet as a possible parent body. The sodium and magnesium content of the iron-class meteoroids is the lowest of all our samples, but it is not zero, suggesting that there are no pure iron meteoroids. The sodium content of the GEM meteor shower shows temporal variations in 2021 compared to the 2019 and 2020 observing seasons. We found no correlation between the sodium content and the perihelion distance for other meteor showers.
Clumpy structures within the turbulent primordial cloud
Authors: Tang Ching-Yao , Chen Ke-Jung 
Published: March 2024

ABSTRACT
The primordial clouds in the mini-haloes hatch the first generation stars of the Universe, which play a crucial role in cosmic evolution. In this paper, we investigate how turbulence impacts the structure of primordial star-forming clouds. Previous cosmological simulations of the first star formation predicted a typical mass of around $\mathrm{ 100 \, M_\odot }$. This conflicts with recent observations of extremely metal-poor stars, suggesting a lower mass scale of about $\mathrm{25 \, M_\odot }$. The discrepancy may arise from unresolved turbulence in the star-forming cloud, driven by primordial gas accretion during mini-halo formation in the previous simulations. To quantitatively examine the turbulence effect on the primordial cloud formation, we employ the adaptive mesh refinement code Enzo to model the gas cloud with primordial composition, including artificially driven turbulence on the cloud scale and relevant gas physics. This artificially driven turbulence utilizes a stochastic forcing model to mimic the unresolved turbulence inside mini-haloes. Our results show that the turbulence with high Mach number and compressional mode effectively fragments the cloud into several clumps, each with dense cores of $\mathrm{22.7 - 174.9 \, M_\odot }$ that undergo Jeans instability to form stars. Fragmentation caused by intense and compressive turbulence prevents a runaway collapse of the cloud. The self-bound clumps with smaller masses in the turbulent primordial clouds suggest a possible pathway to decrease the theoretical mass scale of the first stars, further reconciling the mass discrepancy between simulations and observations.