bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Wolf–Rayet wind yields and nucleosynthesis of Helium stars
Authors: Higgins Erin R , Vink Jorick S , Hirschi Raphael , Laird Alison M , Sander Andreas A C 
Published: August 2024

ABSTRACT
Strong metallicity-dependent winds dominate the evolution of core He-burning, classical Wolf–Rayet (cWR) stars, which eject both H and He-fusion products such as $^{14}$N, $^{12}$C, $^{16}$O, $^{19}$F, $^{22}$Ne, and $^{23}$Na during their evolution. The chemical enrichment from cWRs can be significant. cWR stars are also key sources for neutron production relevant for the weak s-process. We calculate stellar models of cWRs at solar metallicity for a range of initial Helium star masses (12–50 $\rm M_{\odot }$), adopting recent hydrodynamical wind rates. Stellar wind yields are provided for the entire post-main sequence evolution until core O-exhaustion. While literature has previously considered cWRs as a viable source of the radioisotope $^{26}$Al, we confirm that negligible $^{26}$Al is ejected by cWRs since it has decayed to $^{26}$Mg or proton-captured to $^{27}$Al. However, in Paper I, we showed that very massive stars eject substantial quantities of $^{26}$Al, among other elements including N, Ne, and Na, already from the zero-age-main-sequence. Here, we examine the production of $^{19}$F and find that even with lower mass-loss rates than previous studies, our cWR models still eject substantial amounts of $^{19}$F. We provide central neutron densities (N$_{n}$) of a 30 $\rm M_{\odot }$ cWR compared with a 32 $\rm M_{\odot }$ post-VMS WR and confirm that during core He-burning, cWRs produce a significant number of neutrons for the weak s-process via the $^{22}$Ne($\alpha$,n)$^{25}$Mg reaction. Finally, we compare our cWR models with observed [Ne/He], [C/He], and [O/He] ratios of Galactic WC and WO stars.
Ram-pressure stripped radio tails detected in the dynamically active environment of the Shapley Supercluster
Authors: Merluzzi P , Venturi T , Busarello G , Gennaro G Di , Giacintucci S , Casasola V , Krajnović D , Vernstrom T , Carretti E , Smirnov O , Trehaeven K , Anderson C S , Chesters J , Heald G , Hopkins A M , Koribalski B 
Published: August 2024

ABSTRACT
We study the radio continuum emission of four galaxies experiencing ram-pressure stripping in four clusters of the Shapley Supercluster at redshift $z\sim 0.05$. Multiband (235–1367 MHz) radio data, complemented by integral-field spectroscopy, allow us to detect and analyse in detail the non-thermal component both in the galaxy discs and the radio continuum tails. Three galaxies present radio continuum tails that are tens of kiloparsecs long. By deriving the radio spectral index in the inner and outer tails and comparing our findings with the distribution of the extraplanar ionized gas and the results of N-body/hydrodynamical simulations, we demonstrate that these tails are caused by the ram pressure, which, together with the ionized gas, sweeps the magnetic field from the galaxy discs. We suggest that the radio continuum emission in these tails can be differently powered by (i) in situ star formation, (ii) relativistic electrons stripped from the disc, and (iii) shock excitation or a combination of them. All the ram-pressure-stripped galaxies are found in environments where cluster–cluster interactions occurred and/or are ongoing, thus strongly supporting the thesis that cluster and group collisions and mergers may locally increase the ram pressure and trigger hydrodynamical interactions between the intracluster medium and the interstellar medium of galaxies.
The application of machine learning in tidal evolution simulation of star–planet systems
Authors: Guo Shuaishuai , Guo Jianheng , Ji KaiFan , Liu Hui , Xing Lei 
Published: August 2024

ABSTRACT
With the release of a large amount of astronomical data, an increasing number of close-in hot Jupiters have been discovered. Calculating their evolutionary curves using star–planet interaction models presents a challenge. To expedite the generation of evolutionary curves for these close-in hot Jupiter systems, we utilized tidal interaction models established on mesa to create 15 745 samples of star–planet systems and 7500 samples of stars. Additionally, we employed a neural network (Multilayer Perceptron – MLP) to predict the evolutionary curves of the systems, including stellar effective temperature, radius, stellar rotation period, and planetary orbital period. The median relative errors of the predicted evolutionary curves were found to be 0.15 per cent, 0.43 per cent, 2.61 per cent, and 0.57 per cent, respectively. Furthermore, the speed at which we generate evolutionary curves exceeds that of model-generated curves by more than four orders of magnitude. We also extracted features of planetary migration states and utilized lightgbm to classify the samples into six categories for prediction. We found that by combining three types that undergo long-term double synchronization into one label, the classifier effectively recognized these features. Apart from systems experiencing long-term double synchronization, the median relative errors of the predicted evolutionary curves were all below 4 per cent. Our work provides an efficient method to save significant computational resources and time with minimal loss in accuracy. This research also lays the foundation for analysing the evolutionary characteristics of systems under different migration states, aiding in the understanding of the underlying physical mechanisms of such systems. Finally, to a large extent, our approach could replace the calculations of theoretical models.
Automation of finding strong gravitational lenses in the Kilo Degree Survey with U – DenseLens (DenseLens + Segmentation)
Authors: N Bharath Chowdhary , Koopmans Léon V E , Valentijn Edwin A , Kleijn Gijs Verdoes , de Jong Jelte T A , Napolitano Nicola , Li Rui , Tortora Crescenzo , Busillo Valerio , Dong Yue 
Published: August 2024

ABSTRACT
In the context of upcoming large-scale surveys like Euclid, the necessity for the automation of strong lens detection is essential. While existing machine learning pipelines heavily rely on the classification probability (P), this study intends to address the importance of integrating additional metrics, such as Information Content (IC) and the number of pixels above the segmentation threshold ($\rm {\mathit{n}_{s}}$), to alleviate the false positive rate in unbalanced data-sets. In this work, we introduce a segmentation algorithm (U-Net) as a supplementary step in the established strong gravitational lens identification pipeline (Denselens), which primarily utilizes $\rm {\mathit{P}_{mean}}$ and $\rm {IC_{mean}}$ parameters for the detection and ranking. The results demonstrate that the inclusion of segmentation enables significant reduction of false positives by approximately 25 per cent in the final sample extracted from DenseLens, without compromising the identification of strong lenses. The main objective of this study is to automate the strong lens detection process by integrating these three metrics. To achieve this, a decision tree-based selection process is introduced, applied to the Kilo Degree Survey (KiDS) data. This process involves rank-ordering based on classification scores ($\rm {\mathit{P}_{mean}}$), filtering based on Information Content ($\rm {IC_{mean}}$), and segmentation score ($\rm {n_{s}}$). Additionally, the study presents 14 newly discovered strong lensing candidates identified by the U-Denselens network using the KiDS DR4 data.
The TRAPUM Small Magellanic Cloud pulsar survey with MeerKAT – II. Nine new radio timing solutions and glitches from young pulsars
Authors: Carli E , Antonopoulou D , Burgay M , Keith M J , Levin L , Liu Y , Stappers B W , Turner J D , Barr E D , Breton R P , Buchner S , Kramer M , Padmanabh P V , Possenti A , Venkatraman Krishnan V , Venter C , Becker W , Maitra C , Haberl F , Thongmeearkom T 
Published: August 2024

ABSTRACT
We report new radio timing solutions from a 3-yr observing campaign conducted with the MeerKAT and Murriyang telescopes for nine Small Magellanic Cloud pulsars, increasing the number of characterized rotation-powered extragalactic pulsars by 40 per cent. We can infer from our determined parameters that the pulsars are seemingly all isolated, that six are ordinary pulsars, and that three of the recent MeerKAT discoveries have a young characteristic age of under 100 kyr and have undergone a spin-up glitch. Two of the sources, PSRs J0040$-$7337 and J0048$-$7317, are energetic young pulsars with spin-down luminosities of the order of 10$^{36}$ erg s$^{-1}$. They both experienced a large glitch, with a change in frequency of about 30 $\mu$Hz, and a frequency derivative change of order $-10^{-14}$ Hz s$^{-1}$. These glitches, the inferred glitch rate, and the properties of these pulsars (including potentially high inter-glitch braking indices) suggest these neutron stars might be Vela-like repeating glitchers and should be closely monitored in the future. The position and energetics of PSR J0048$-$7317 confirm it is powering a new pulsar wind nebula (PWN) detected as a radio continuum source; and similarly the association of PSR J0040$-$7337 with the PWN of supernova remnant (SNR) DEM S5 (for which we present a new Chandra image) is strengthened. Finally, PSR J0040$-$7335 is also contained within the same SNR but is a chance superposition. It has also been seen to glitch with a change of frequency of $10^{-2}$ $\mu$Hz. This work more than doubles the characterized population of SMC radio pulsars.
The effect of dynamical interactions in stellar birth environments on the orbits of young close-in planetary systems
Authors: Schoettler Christina , Owen James E 
Published: August 2024

ABSTRACT
Stars do not form in isolation but together with other stars, and often in a clustered environment. Depending on the initial conditions in these environments, such as initial density and substructure, the distances of encounters between stars will differ. These encounters can also affect just-formed exoplanetary systems. Using N-body simulations, we show the effect of a single fly-by on a common type of exoplanetary system: close-in super-Earths/sub-Neptunes with or without a distant giant planet. Even a single encounter can significantly modify the architecture of these exoplanetary systems over their long lifetimes. We test fly-bys with different characteristics, such as distance and mass, and show how they perturb the inner planets long after the encounter, leading to collisions and mutual inclination excitation, which can significantly modify the observed architecture of these systems in transit. We find that our initially four-planet inner systems reduce to three or two inner planets depending on their initial separation and that the mutual inclinations of these remaining planets can be high enough to reduce the number of observable, transiting planets. In our 500 Myr simulations, we show that this reduction in the number of transiting planets due to stellar fly-bys can contribute to the observed excess of single-transit systems.
The Keck-HGCA Pilot Survey – II. Direct imaging discovery of HD 63754 B, a ∼20 au massive companion near the hydrogen burning limit
Authors: Li Yiting , Brandt Timothy D , Franson Kyle , An Qier , Tobin Taylor , Currie Thayne , Chen Minghan , Wang Lanxuan , Dupuy Trent J , Bowens-Rubin Rachel , Salama Maïssa , Lewis Briley L , Gibbs Aidan , Bowler Brendan P , Jensen-Clem Rebecca , Faherty Jacqueline , Fitzgerald Michael P , Mazin Benjamin A 
Published: August 2024

ABSTRACT
We present the joint astrometric and direct imaging discovery, mass measurement, and orbital analysis of HD 63754 B (HIP 38216 B), a companion near the stellar-substellar boundary orbiting $\sim$20 au from its Sun-like host. HD 63754 was observed in our ongoing high-contrast imaging survey targeting stars with significant proper-motion accelerations between Hipparcos and Gaia consistent with wide-separation substellar companions. We utilized archival High Resolution Echelle Spectrograph and High Accuracy Radial Velocity Planet Searcher radial velocity (RV) data, together with the host star’s astrometric acceleration extracted from the Hipparcos–Gaia Catalog of Accelerations, to predict the location of the candidate companion around HD 63754 A. We subsequently imaged HD 63754 B at its predicted location using the Near Infrared Camera 2 (NIRC2) in the $L^{\prime }$ band at the W. M. Keck Observatory. We then jointly modelled the orbit of HD 63754 B with RVs, Hipparcos–Gaia accelerations, and our new relative astrometry, measuring a dynamical mass of ${81.9}_{-5.8}^{+6.4} {M_{\rm Jup}}$, an eccentricity of ${0.260}_{-0.059}^{+0.065}$, and a nearly face-on inclination of $174.\!\!^\circ 81_{-0.50}^{+0.48}$. For HD 63754 B, we obtain an $L^{\prime }$-band absolute magnitude of $L^{\prime } = 11.39\pm 0.06$ mag, from which we infer a bolometric luminosity of $\rm{log(L_{\rm bol}/{\rm{L}_{\odot}})= -4.55 \pm 0.08}$ dex using a comparison sample of L and T dwarfs with measured luminosities. Although uncertainties linger in age and dynamical mass estimates, our analysis points towards HD 63754 B’s identity as a brown dwarf on the L/T transition rather than a low-mass star, indicated by its inferred bolometric luminosity and model-estimated effective temperature. Future RV, spectroscopic, and astrometric data such as those from JWST and Gaia Data Release 4 will clarify HD 63754 B’s mass, and enable spectral typing and atmospheric characterization.
Approximate analytical solutions of the homologous collapse’s radial evolution in time
Authors: Calvo Manuel , Elipe Antonio , Rández Luis 
Published: August 2024

ABSTRACT
The homologous collapse of a uniform density sphere under its self-gravity is a well-known model in cosmological studies. In the analytical integration, the evolution of the radius of the sphere is defined in terms of a parameter that is related to the physical time through a transcendental equation. The aim of this note is to construct new approximate solutions of this transcendental equation. After close examination of the piecewise Padé approximation introduced in a recent paper by Zhou and collaborators, several modifications that improve the accuracy of this approximation with the same computational cost are proposed. This new approximation shows that the use of piecewise Hermite interpolation leads to approximate solutions with continuity and much higher accuracy than Padé interpolants. Numerical experiments that confirm the above results are also presented.
On the fate of the secondary white dwarf in double-degenerate double-detonation Type Ia supernovae – II. 3D synthetic observables
Authors: Pollin J M , Sim S A , Pakmor R , Callan F P , Collins C E , Shingles L J , Röpke F K , Srivastav S 
Published: August 2024

ABSTRACT
A leading model for Type Ia supernovae involves the double-detonation of a sub-Chandrasekhar mass white dwarf. Double-detonations arise when a surface helium shell detonation generates shockwaves that trigger a core detonation; this mechanism may be triggered via accretion or during the merger of binaries. Most previous double-detonation simulations only included the primary white dwarf; however, the fate of the secondary has significant observational consequences. Recently, hydrodynamic simulations accounted for the companion in double-degenerate double-detonation mergers. In the merger of a 1.05 M$_{\odot }$ primary white dwarf and 0.7 M$_{\odot }$ secondary white dwarf, the primary consistently detonates while the fate of the secondary remains uncertain. We consider two versions of this scenario, one in which the secondary survives and another in which it detonates. We present the first 3D radiative transfer calculations for these models and show that the synthetic observables for both models are similar and match properties of the peculiar 02es-like subclass of Type Ia supernovae. Our calculations show angle dependencies sensitive to the companion’s fate, and we can obtain a closer spectroscopic match to normal Type Ia supernovae when the secondary detonates and the effects of helium detonation ash are minimized. The asymmetry in the width–luminosity relationship is comparable to previous double-detonation models, but the overall spread is increased with a secondary detonation. The secondary detonation has a meaningful impact on all synthetic observables; however, multidimensional nebular phase calculations are needed to support or rule out either model as a likely explanation for Type Ia supernovae.
Statistical properties of filaments in the cosmic web
Authors: Zhang Youcai , Guo Hong , Yang Xiaohu , Wang Peng 
Published: August 2024

ABSTRACT
In the context of the cosmological and constrained Exploring the Local Universe with the reConstructed Initial Density field (ELUCID) simulation, this study explores the statistical characteristics of filaments within the cosmic web, focussing on aspects such as the distribution of filament lengths and their radial density profiles. Using the classification of the cosmic web environment through the Hessian matrix of the density field, our primary focus is on how cosmic structures react to the two variables $R_{\rm s}$ and $\lambda _{\rm th}$. The findings show that the volume fractions of knots, filaments, sheets, and voids are highly influenced by the threshold parameter $\lambda _{\rm th}$, with only a slight influence from the smoothing length $R_{\rm s}$. The central axis of the cylindrical filament is pinpointed using the medial-axis thinning algorithm of the COsmic Web Skeleton (COWS) method. It is observed that median filament lengths tend to increase as the smoothing lengths increase. Analysis of filament length functions at different values of $R_{\rm s}$ indicates a reduction in shorter filaments and an increase in longer filaments as $R_{\rm s}$ increases, peaking around $2.5R_{\rm s}$. The study also shows that the radial density profiles of filaments are markedly affected by the parameters $R_{\rm s}$ and $\lambda _{\rm th}$, showing a valley at approximately $2R_{\rm s}$, with increases in the threshold leading to higher amplitudes of the density profile. Moreover, shorter filaments tend to have denser profiles than their longer counterparts.
Parity-odd power spectra: concise statistics for cosmological parity violation
Authors: Jamieson Drew , Caravano Angelo , Hou Jiamin , Slepian Zachary , Komatsu Eiichiro 
Published: August 2024

ABSTRACT
We introduce the parity-odd power (POP) spectra, a novel set of observables for probing parity violation in cosmological N-point statistics. POP spectra are derived from composite fields obtained by applying non-linear transformations, involving also gradients, curls, and filtering functions, to a scalar field. This compresses the parity-odd trispectrum into a power spectrum. These new statistics offer several advantages: they are computationally fast to construct, estimating their covariance is less demanding compared to estimating that of the full parity-odd trispectrum, and they are simple to model theoretically. We measure the POP spectra on simulations of a scalar field with a specific parity-odd trispectrum shape. We compare these measurements to semi-analytic theoretical calculations and find agreement. We also explore extensions and generalizations of these parity-odd observables.
An improved Tully–Fisher estimate of H0
Authors: Boubel Paula , Colless Matthew , Said Khaled , Staveley-Smith Lister 
Published: August 2024

ABSTRACT
We propose an improved comprehensive method for determining the Hubble constant ($H_0$) using the Tully–Fisher relation. By fitting a peculiar velocity model in conjunction with the Tully–Fisher relation, all available data can be used to derive self-consistent Tully–Fisher parameters. In comparison to previous approaches, our method offers several improvements: it can be readily generalized to different forms of the Tully–Fisher relation and its intrinsic scatter; it uses a peculiar velocity model to predict distances more accurately; it can account for all selection effects; it uses the entire data set to fit the Tully–Fisher relation; and it is fully self-consistent. The Tully–Fisher relation zero-point is calibrated using the subset of galaxies with distances from absolute distance indicators. We demonstrate this method on the Cosmicflows-4 catalogue i-band and $W1$-band Tully–Fisher samples and show that the uncertainties from fitting the Tully–Fisher relation amount to only 0.2 km s$^{-1}$ Mpc$^{-1}$. Using all available absolute distance calibrators, we obtain $H_0=73.3$ $\pm$ 2.1 (stat) $\pm$ 3.5 (sys) km s$^{-1}$ Mpc$^{-1}$, where the statistical uncertainty is dominated by the small number of galaxies with absolute distance estimates. The substantial systematic uncertainty reflects inconsistencies between various zero-point calibrations of the Cepheid period–luminosity relation, the tip of the red giant branch standard candle, and the Type Ia supernova standard candle. However, given a reliable set of absolute distance calibrators, our method promises enhanced precision in $H_0$ measurements from large new Tully–Fisher samples such as the WALLABY survey.
TF-High-Evolutionary: In Vivo Mutagenesis of Gene Regulatory Networks for the Study of the Genetics and Evolution of the Drosophila Regulatory Genome
Authors: Li Xueying C , Srinivasan Vani , Laiker Ian , Misunou Natalia , Frankel Nicolás , Pallares Luisa F , Crocker Justin 
Published: August 2024

Abstract
Understanding the evolutionary potential of mutations in gene regulatory networks is essential to furthering the study of evolution and development. However, in multicellular systems, genetic manipulation of regulatory networks in a targeted and high-throughput way remains challenging. In this study, we designed TF-High-Evolutionary (HighEvo), a transcription factor (TF) fused with a base editor (activation-induced deaminase), to continuously induce germline mutations at TF-binding sites across regulatory networks in Drosophila. Populations of flies expressing TF-HighEvo in their germlines accumulated mutations at rates an order of magnitude higher than natural populations. Importantly, these mutations accumulated around the targeted TF-binding sites across the genome, leading to distinct morphological phenotypes consistent with the developmental roles of the tagged TFs. As such, this TF-HighEvo method allows the interrogation of the mutational space of gene regulatory networks at scale and can serve as a powerful reagent for experimental evolution and genetic screens focused on the regulatory genome.
Land snail assemblages along altitudinal gradients on Mount Semeru, the highest montane forest in Java, Indonesia
Authors: Nurhayati Putri Afin , Nurinsiyah Ayu Savitri , Atmowidi Tri , Priawandiputra Windra 
Published: August 2024

ABSTRACT
We conducted research on land snail diversity on the highest volcanic mountain in Java, Mt Semeru. This research aimed to gain data on the land snail species diversity in the area as well as analyse environmental variables that affect the land snail assemblages along the altitudinal gradients. A total of 40 plots of 10 × 10 m2 were examined in the altitudinal gradient of 800–1,200, 1,201–1,600, 1,601–2,000 and 2,001–2,400 m asl using a timed search method. In total, 788 individuals of land snails were collected, belonging to 22 species from 14 families. Fifteen species were new records for the area. Five endemic species were recorded on Mt Semeru. A single introduced species, Bradybaena similaris was found abundantly on the mountain at an altitude of more than 2,000 m asl. Multiple linear regression analyses showed a unimodal response of species richness for altitude, temperature and precipitation sums on Mt Semeru. In addition to these environmental variables, species richness is influenced by land use type and soil pH. These findings suggest that species and ecosystem management at the altitude 2,001–2,400 m asl is necessary to conserve endemic land snail species, which were found most abundantly at this altitude.