bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamical study of Geminid formation assuming a rotational instability scenario
Authors: Jo Hangbin , Ishiguro Masateru 
Published: January 2024

Context. Various ideas have been proposed to explain the formation of the Geminid meteoroid stream from the asteroid (3200) Phaethon. However, little has been studied regarding whether the Geminid formation could be the result of mass ejection via rotational instability of this asteroid.
Aims. In this work, we present the first dynamical study of the Geminid formation taking into account low-velocity mass ejection caused by Phaethon’s rotational instability.
Methods. We conducted numerical simulations for 1-mm and 1-cm particles ejected in a wide range of ejection epochs (103–105 yr ago). We computed the minimum orbital intersecting distance (MOID) of the dust particles as the realistic condition, that is, the Earth’s radius and the Earth–Moon distance to be observed as the Geminid meteoroid stream.
Results. We found that the low-velocity ejection model produced the Geminid-like meteoroid stream when the dust particles were ejected more than ~2000 yr ago. In this case, close encounters with terrestrial planets would transport some dust particles from the Phaethon orbit (the current MOID is as large as ~460 Earth radii) to the Earth-intersecting orbits. The optimal ejection epoch and the estimated mass were 18 000 yr ago and ~1010–1014 g (<0.1% of the Phaethon mass).
Conclusions. Our results suggest that the JAXA DESTINY+ mission has the potential to find evidence of recent rotational instability recorded on the surface of Phaethon.
Three sub-Jovian-mass microlensing planets: MOA-2022-BLG-563Lb, KMT-2023-BLG-0469Lb, and KMT-2023-BLG-0735Lb
Authors: Han Cheongho , Jung Youn Kil , Bond Ian A. , Gould Andrew , Albrow Michael D. , Chung Sun-Ju , Hwang Kyu-Ha , Lee Chung-Uk , Ryu Yoon-Hyun , Shin In-Gu , Shvartzvald Yossi , Yang Hongjing , Yee Jennifer C. , Zang Weicheng , Cha Sang-Mok , Kim Doeon , Kim Dong-Jin , Kim Seung-Lee , Lee Dong-Joo , Lee Yongseok , Park Byeong-Gon , Pogge Richard W. , Abe Fumio , Barry Richard , Bennett David P. , Bhattacharya Aparna , Fujii Hirosame , Fukui Akihiko , Hamada Ryusei , Hirao Yuki , Silva Stela Ishitani , Itow Yoshitaka , Kirikawa Rintaro , Koshimoto Naoki , Matsubara Yutaka , Miyazaki Shota , Muraki Yasushi , Olmschenk Greg , Ranc Clément , Rattenbury Nicholas J. , Satoh Yuki , Sumi Takahiro , Suzuki Daisuke , Tomoyoshi Mio , Tristram Paul J. , Vandorou Aikaterini , Yama Hibiki , Yamashita Kansuke 
Published: January 2024

Aims. We analyze the anomalies appearing in the light curves of the three microlensing events MOA-2022-BLG-563, KMT-2023-BLG-0469, and KMT-2023-BLG-0735. The anomalies exhibit common short-term dip features that appear near the peak.
Methods. From the detailed analyses of the light curves, we find that the anomalies were produced by planets accompanied by the lenses of the events. For all three events, the estimated mass ratios between the planet and host are on the order of 10−4: q ~ 8 × 10−4 for MOA-2022-BLG-563L, q ~ 2.5 × 10−4 for KMT-2023-BLG-0469L, and q ~ 1.9 × 10−4 for KMT-2023-BLG-0735L. The interpretations of the anomalies are subject to a common inner-outer degeneracy, which causes ambiguity when estimating the projected planet-host separation.
Results. We estimated the planet mass, Mp, host mass, Mh, and distance, DL, to the planetary system by conducting Bayesian analyses using the observables of the events. The estimated physical parameters of the planetary systems are (Mh/M⊙, Mp/MJ, DL/kpc) = (0.48−0.30+0.36, 0.40−0.25+0.31, 6.53−1.57+1.12) for MOA-2022-BLG-563L, (0.47−0.26+0.35, 0.124−0.067+0.092, 7.07−1.19+1.03) for KMT-2023-BLG-0469L, and (0.62−0.35+0.34, 0.125−0.070+0.068, 6.26−1.67+1.27) for KMT-2023-BLG-0735L. According to the estimated parameters, all planets are cold planets with projected separations that are greater than the snow lines of the planetary systems, they have masses that lie between the masses of Uranus and Jupiter of the Solar System, and the hosts of the planets are main-sequence stars that are less massive than the Sun. In all cases, the planetary systems are more likely to be in the bulge with probabilities Pbulge = 64%, 73%, and 56% for MOA-2022-BLG-563, KMT-2023-BLG-0469, and KMT-2023-BLG-0735, respectively.
Airy worlds or barren rocks? On the survivability of secondary atmospheres around the TRAPPIST-1 planets
Authors: Van Looveren Gwenaël , Güdel Manuel , Boro Saikia Sudeshna , Kislyakova Kristina 
Published: January 2024

Context. The James Webb Space Telescope is currently at the forefront of the search for atmospheres of exoplanets. However, the observation of atmospheres of Earth-like planets pushes the limits of the instruments, and often, multiple observations must be combined. As with most instruments, telescope time is unfortunately extremely limited. Over the course of cycle 1, approximately 100 hours have been dedicated to the TRAPPIST-1 planets. This system is therefore studied in unusually great detail. However, the first two sets of observations of the innermost two planets show that these planets most likely lack a thick atmosphere. The question therefore arises whether terrestrial planets around M stars have atmospheres or do not have atmospheres at all.
Aims. We aim to determine the atmospheric survivability of the TRAPPIST-1 planets by modelling the response of the upper atmosphere to incoming stellar high-energy radiation. Through this case study, we also aim to learn more about rocky planet atmospheres in the habitable zone around low-mass M dwarfs.
Methods. We simulated the upper atmospheres of the TRAPPIST-1 planets using the Kompot code, which is a self-consistent thermo-chemical code. Specifically, we studied the atmospheric mass loss due to Jeans escape induced by stellar high-energy radiation. This was achieved through a grid of models that account for the differences in planetary properties and irradiances of the TRAPPIST-1 planets, as well as different atmospheric properties. This grid allows for the explorations of the different factors influencing atmospheric loss.
Results. The present-day irradiance of the TRAPPIST-1 planets would lead to the loss of an Earth’s atmosphere within just some hundreds of million years. When we take into account the much more active early stages of a low-mass M dwarf, the planets undergo a period of even more extreme mass loss, regardless of planetary mass or atmospheric composition.
Conclusions. The losses calculated in this work indicate that it is unlikely that any significant atmosphere could survive for any extended amount of time around any of the TRAPPIST-1 planets based on present-day irradiance levels. The assumptions used here allow us to generalise the results, and we conclude that the results tentatively indicate that this conclusion applies to all Earth-like planets in the habitable zones of low-mass M dwarfs.
Exploring the hardness of the ionising radiation with the infrared softness diagram
Authors: Pérez-Montero E. , Fernández-Ontiveros J. A. , Pérez-Díaz B. , Vílchez J. M. , Kumari N. , Amorín R. 
Published: January 2024

Aims. We explored the softness parameter in the infrared, ηIR′, whose main purpose is the characterisation of the hardness of the incident ionising radiation in emission-line nebulae. This parameter is obtained from the combination of mid-infrared wavelength range transitions corresponding to consecutive ionisation stages in star-forming regions.
Methods. We compiled observational data from a sample of star-forming galaxies (SFGs), including luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs), to study the ηIR′ and its equivalent expression in two dimensions, the softness diagram. We compared them with predictions from photoionisation models to determine the shape of the ionising continuum energy distribution in each case. We also used the measured emission-line ratios as input for HCMISTRY-TEFF-IR, a code that performs a Bayesian-like comparison with photoionisation model predictions in order to quantify the equivalent effective temperature (T*) and the ionisation parameter.
Results. We found similar average values within the errors of ηIR′ in (U)LIRGs (−0.57) in the rest of the SFGs (−0.51), which could be interpreted as indicative of a similar incident radiation field. This result is confirmed from the analysis using HCM-TEFF-IR, which simultaneously points to a slightly lower, although similar within the errors, T* scale for (U)LIRGs, even when a higher dust-to-gas mass ratio is considered in the models for these objects. These derived T* values are compatible with the ionisation from massive stars, without any need of harder ionising sources, both for (U)LIRGs and the rest of the SFGs. However, the derived T* in (U)LIRGs do not show any correlation with metallicity. This could be interpreted as a sign that their similar average T* values are due to the attenuation of the energetic incident flux from massive stars by the heated dust mixed with the gas. This is supported by the known very large amounts of small grains associated with the very high star formation rates measured in galaxies of this type.
Constraining ΛLTB models with galaxy cluster counts from next-generation surveys
Authors: Sakr Z. , Carvalho A. , Da Silva A. , García-Bellido J. , Mimoso J. P. , Camarena D. , Nesseris S. , Martins C. J. A. P. , Nunes N. , Sapone D. 
Published: January 2024

Context. The Universe’s assumed homogeneity and isotropy is known as the cosmological principle. It is one of the assumptions that led to the Friedmann-Lemaître-Robertson-Walker (FLRW) metric and is a cornerstone of modern cosmology, because the metric plays a crucial role in the determination of the cosmological observables. Thus, it is of paramount importance to question this principle and perform observational tests that may falsify it.
Aims. Here, we explore the use of galaxy cluster counts as a probe of a large-scale inhomogeneity, which is a novel approach to the study of inhomogeneous models, and we determine the precision with which future galaxy cluster surveys will be able to test the cosmological principle.
Methods. We present forecast constraints on the inhomogeneous Lemaître-Tolman-Bondi (LTB) model with a cosmological constant and cold dark matter, basically a ΛCDM model endowed with a spherical, large-scale inhomogeneity, from a combination of simulated data according to a compilation of ‘Stage-IV’ galaxy surveys. For that, we followed a methodology that involves the use of a mass function correction from numerical N-body simulations of an LTB cosmology.
Results. When considering the ΛCDM fiducial model as a baseline for constructing our mock catalogs, we find that our combination of the forthcoming cluster surveys will improve the constraints on the cosmological principle parameters and the FLRW parameters by about 50% with respect to previous similar forecasts performed using geometrical and linear growth of structure probes, with ±20% of variations depending on the level of knowledge of systematic effects.
Conclusions. These results indicate that galaxy cluster abundances are sensitive probes of inhomogeneity and that next-generation galaxy cluster surveys will thoroughly test homogeneity at cosmological scales, tightening the constraints on possible violations of the cosmological principle in the framework of ΛLTB scenarios.
Contamination of spectroscopic observations by satellite constellations
Authors: Hainaut O. R. , Moehler S. 
Published: January 2024

Context. With the onset of large telecommunication constellations, the number of satellites on low orbits has dramatically increased over the past years, raising concerns among the astronomical community about their impact on observations.
Aims. Since spectroscopic observations represent a large fraction of professional astronomical observations and given that spectro-graphs lack spatial information that can reveal the presence of a satellite, this paper is focused on how satellites affect spectroscopic optical observations.
Methods. We simulated how often satellites contaminate spectrograph observations by using realistic constellations with over 400 000 objects. We counted the satellites that crossed a representative 10 × 1" slit during a 1000 s exposure, for different solar elevations and observation directions. We also measured how a satellite affects a spectrum by using real data from different scientific targets and a scaled solar analog as the satellite. We then used standard tools to measure astrophysical parameters and compare them with the clean spectrum.
Results. As expected, the fraction of affected spectra varies dramatically with the direction of the observation and the elevation of the sun, with a maximum of 10% at twilight down to no contamination when the sun reaches −30°, with a nightly average of ~2%. The probability of a satellite crossing over the astronomical target will be further reduced depending on the target’s apparent size. Because of the fast motion of the satellites and the limiting magnitude of the spectrographs, high-resolution instruments are essentially blind to most satellites. For lower resolution spectrographs, the effect on the measured astrophysical parameters depends strongly on the signal-to-noise ratio of the exposure, longer exposures on brighter targets being the least affected at ≲1%. Satellites that are brighter and/or higher than the constellation satellites, while less numerous, can also contaminate the spectra.
Conclusions. Satellites (either coming from a large constellation or not) have the potential to contaminate spectra. While the fraction of affected spectra is likely to remain low even with a number of satellites about 100× larger than today, some of these contaminated spectra will be difficult to identify, as is already the case with existing satellites and asteroids. The best mitigation is to ensure that their brightness is fainter than V = 7 and that the satellites’ absolute magnitude V1000 km is also fainter than 7, and whenever possible to shoot multiple exposures.
The Baade-Wesselink projection factor of RR Lyrae stars
Authors: Bras Garance , Kervella Pierre , Trahin Boris , Wielgórski Piotr , Zgirski Bartłomiej , Mérand Antoine , Nardetto Nicolas , Gallenne Alexandre , Hocdé Vincent , Breuval Louise , Afanasiev Anton , Pietrzyński Grzegorz , Gieren Wolfgang 
Published: January 2024

Context. The application of the parallax-of-pulsation (PoP) technique to determine the distances of pulsating stars implies the use of a scaling parameter, namely the projection factor (p-factor), which is required to transform disc-integrated radial velocities (RVs) into photospheric expansion velocities. The value of this parameter is poorly known and is still debated. Most present applications of the PoP technique assume a constant p-factor. However, it may actually depend on the physical parameters of each star, as past studies designed to calibrate the p-factor (predominantly for Cepheids) led to a broad range of individual values.
Aims. We aim to calibrate the p-factors of a sample of RR Lyrae stars (RRLs) in order to compare them with classical Cepheids (CCs). Due to their higher surface gravity, RRLs have more compact atmospheres, and therefore provide a valuable comparison with their supergiant siblings.
Methods. We determined the p-factor of 17 RRLs by modelling their pulsation using the SPIPS code. The models are constrained using Gaia DR3 parallaxes, photometry, and new RVs that we collected with the OHP/SOPHIE spectrograph. We carefully examine the different steps of the PoP technique, in particular the method used to determine the RV from spectra using the classical approach based on the cross-correlation function (CCF).
Results. The method employed to extract the RV from the CCF has a strong impact on the p-factor, that is, of up to 10%. However, this choice of method results in a global scaling of the p-factor, and only marginally affects the scatter of p within the sample for a given method. Over our RRL sample, we find a mean value of p = 1.248 ± 0.022 for RVs derived using a Gaussian fit of the CCF. There is no evidence for a different value of the p-factor of RRLs, although its distribution for RRLs appears significantly less scattered (σ ≈ 7%) than that for CCs (σ ≈ 12%).
Conclusions. The p-factor does not appear to depend in a simple way on fundamental stellar parameters (pulsation period, radius, metallicity, amplitude of the RV curve). We argue that large-amplitude dynamical phenomena occurring in the atmospheres of RRLs (and CCs) during their pulsation affect the relative velocity of the spectral line-forming regions compared to the velocity of the photosphere.
Locked differential rotation in core-helium burning red giants
Authors: Mosser B. , Dréau G. , Pinçon C. , Deheuvels S. , Belkacem K. , Lebreton Y. , Goupil M.-J. , Michel E. 
Published: January 2024

Context. Oscillation modes of a mixed character are able to probe the inner region of evolved low-mass stars and offer access to a range of information, in particular, the mean core rotation. Ensemble asteroseismology observations are then able to provide clear views on the transfer of angular momentum when stars evolve as red giants.
Aims. Previous catalogs of core rotation rates in evolved low-mass stars have focussed on hydrogen-shell burning stars. Our aim is to complete the compilation of rotation measurements toward more evolved stages, with a detailed analysis of the mean core rotation in core-helium burning giants.
Methods. The asymptotic expansion for dipole mixed modes allows us to fit oscillation spectra of red clump stars and derive their core rotation rates. We used a range of prior seismic analyses, complete with new data, to get statistically significant results.
Results. We measured the mean core rotation rates for more than 1500 red clump stars. We find that the evolution of the core rotation rate in core-helium-burning stars scales with the inverse square of the stellar radius, with a small dependence on mass.
Conclusions. Assuming the conservation of the global angular momentum, a simple model allows us to infer that the mean core rotation and envelope rotation are necessarily coupled. The coupling mechanism ensures that the differential rotation in core-helium-burning red giants is locked.
Hunting young stars in the Galactic centre
Authors: Nogueras-Lara F. 
Published: January 2024

Context. The Galactic centre stands out as the most prolific star-forming environment of the Galaxy when averaged over volume. In the last 30 million years, it has witnessed the formation of ∼106 M⊙ of stars. However, crowding and high extinction hamper their detection and, up to now, only a small fraction of the expected mass of young stars has been identified.
Aims. We aim to detect hidden young stars at the Galactic centre by analysing the stellar population in Sagittarius (Sgr) C. This is a region at the western edge of the nuclear stellar disc whose HII emission makes it a perfect candidate to host young stars.
Methods.We built dereddened luminosity functions for Sgr C and a control field in the central region of the nuclear stellar disc, and fitted them with a linear combination of theoretical models to analyse their stellar population.
Results. We find that Sgr C hosts several 105 M⊙ of young stars. We compared our results with the recently discovered young stellar population in Sgr B1, which is situated at the opposite edge of the nuclear stellar disc. We estimated that the Sgr C young stars are ∼20 Myr old, and likely show the next evolutionary step of the slightly younger stars in Sgr B1. Our findings contribute to addressing the discrepancy between the expected and the detected number of young stars in the Galactic centre, and shed light on their evolution in this extreme environment. As a secondary result, we find an intermediate-age stellar population in Sgr C (∼50% of its stellar mass with an age of between 2 and 7 Gyr), which is not present in the innermost regions of the nuclear stellar disc (dominated by stars > 7 Gyr). This supports the existence of an age gradient and favours an inside-out formation of the nuclear stellar disc.
3D NLTE modelling of Y and Eu
Authors: Storm N. , Barklem P. S. , Yakovleva S. A. , Belyaev A. K. , Palmeri P. , Quinet P. , Lodders K. , Bergemann M. , Hoppe R. 
Published: January 2024

Context. Abundances of s- and r-process elements in Sun-like stars constrain nucleosynthesis in extreme astrophysical events, such as compact binary mergers and explosions of highly magnetised rapidly rotating massive stars.
Aims. We measure solar abundances of yttrium (Y) and europium (Eu) using 3D non-local thermal equilibrium (NLTE) models. We use the model to determine the abundance of Y, and also explore the model’s ability to reproduce the solar centre-to-limb variation of its lines. In addition, we determine the Eu abundance using solar disc-centre and integrated flux spectra.
Methods. We developed an NLTE model of Eu and updated our model of Y with collisional data from detailed quantum-mechanical calculations. We used the IAG spatially resolved high-resolution solar spectra to derive the solar abundances of Y across the solar disc and of Eu for integrated flux and at disc centre using a set of carefully selected lines and a 3D radiation-hydrodynamics model of the solar atmosphere.
Results. We find 3D NLTE solar abundances of A(Y)3D NLTE = 2.30 ± 0.03stat ± 0.07syst dex based on observations at all angles and A(Eu) = 0.57 ± 0.01stat ± 0.06syst dex based on the integrated flux and disc-centre intensity. 3D NLTE modelling offers the most consistent abundances across the solar disc, and resolves the problem of severe systematic bias in Y and Eu abundances inherent to 1D LTE, 1D NLTE, and 3D LTE modelling.
Lebensalltag und psychosoziale Gesundheit älterer Menschen
mit kognitiven Beeinträchtigungen während der
COVID-19-Pandemie
Authors: Nikelski Angela , Trompetter Eva M. , Boekholt Melanie , Schumacher-Schönert Fanny , Rädke Anika , Michalowsky Bernhard , Vollmar Horst Christian , Hoffmann Wolfgang , Driessen Martin , Thyrian Jochen René , Kreisel Stefan H. 
Published: January 2024

Zusammenfassung
Ziel Ziel ist die Analyse pandemiebedingter Auswirkungen auf den Alltag
und die psychosoziale Gesundheit der bislang wenig untersuchten vulnerablen
Gruppe zu Hause lebender, kognitiv beeinträchtigter älterer
Menschen.
Methodik Mittels strukturierter Telefoninterviews 2020
(n+=+141) und 2021 (n+=+107)
wurden über 65-Jährige mit kognitiven Beeinträchtigungen
(MMSE Ø 23,4) befragt. Die hier vorgestellten Ergebnisse aus 2021
reflektieren Erfahrungen und Einstellungen, Auswirkungen auf den Alltag und die
Versorgung sowie psychosoziale Belastungen und Ressourcen. Für
n+=+66 erfolgt eine längsschnittliche Analyse
ausgewählter Belastungsindikatoren.
Ergebnisse Auch in Anbetracht moderater Auswirkungen auf den Alltag und
die Versorgung und zunehmender Sorgen erweist sich die psychosoziale Gesundheit
insgesamt als gut und im zeitlichen Verlauf als relativ stabil.
Schlussfolgerung Die Befragten verfügen über ein hohes
Maß an personalen und sozialen Ressourcen und ihr Umgang mit
Einschränkungen ist durch Akzeptanz und Anpassungsbereitschaft
gekennzeichnet.
Continuous Flow Multigram-Scale Synthesis of Cetylpyridinium Chloride
Authors: Patel Kashyap , Kapdi Anant R. , Shinde Manish Manohar , Veeramani Karuna , Oruganti Srinivas 
Published: January 2024

AbstractCetylpyridinium chloride is popularly employed as an antimicrobial agent in high-volume commodity and consumer products. Given its high tonnage requirements annually, challenges in its synthesis using conventional batch manufacturing involving higher reaction temperatures at scale, lower yields and purity, and excessively long reaction times could be circumvented by adopting continuous flow as a safe and sustainable approach. We herein report a facile, gram-scale continuous flow protocol for the synthesis of cetylpyridinium chloride (CPC) that reduces reaction time from ≥24 hours to 30 minutes with an isolated product yield of >90% and an HPLC purity of >99%.