bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of bar origin and morphology on stellar migration
Authors: Iles Elizabeth J , Pettitt Alex R , Okamoto Takashi , Kawata Daisuke 
Published: November 2023

ABSTRACT
Different mechanisms driving bar structure formation indicate that bar origins should be distinguishable in the stellar populations of galaxies. To study how these origins affect different bar morphologies and impact stellar orbits and migration, we analyse three simulated discs which are representative of bar formation under isolated evolution motivated by disc instability, and interaction-driven tidal development. The first isolated disc and the tidally driven disc produce similar bar structure, while the second isolated disc, generated by the tidal initial condition without the companion, is visibly dissimilar. Changes to radial and vertical positions, angular momentum in the disc-plane, orbital eccentricity, and the subsequent disc metallicities are assessed, as is the dependence on stellar age and formation radii. Bar origin is distinguishable, with the tidal disc displaying larger migration overall, higher metallicity difference between the inner and outer disc, and a population of inner disc stars displaced to large radii and below the disc-plane. The effect of closest approach on populations of stars formed before, after, and during this period is evident. However, bar morphology is also found to be a significant factor in the evolution of disc stellar properties, with similar bars producing similar traits in migration tendency with radius, particularly in vertical stellar motion and in the evolution of central metallicity features.
thesan-hr: galaxies in the Epoch of Reionization in warm dark matter, fuzzy dark matter, and interacting dark matter
Authors: Shen Xuejian , Borrow Josh , Vogelsberger Mark , Garaldi Enrico , Smith Aaron , Kannan Rahul , Tacchella Sandro , Zavala Jesús , Hernquist Lars , Yeh Jessica Y-C , Zheng Chunyuan 
Published: November 2023

ABSTRACT
Using high-resolution cosmological radiation-hydrodynamic (RHD) simulations (thesan-hr), we explore the impact of alternative dark matter (altDM) models on galaxies during the Epoch of Reionization. The simulations adopt the IllustrisTNG galaxy formation model. We focus on altDM models that exhibit small-scale suppression of the matter power spectrum, namely warm dark matter (WDM), fuzzy dark matter (FDM), and interacting dark matter (IDM) with strong dark acoustic oscillations (sDAO). In altDM scenarios, both the halo mass functions and the ultraviolet luminosity functions at z ≳ 6 are suppressed at the low-mass/faint end, leading to delayed global star formation and reionization histories. However, strong non-linear effects enable altDM models to ‘catch up’ with cold dark matter (CDM) in terms of star formation and reionization. The specific star formation rates are enhanced in halos below the half-power mass in altDM models. This enhancement coincides with increased gas abundance, reduced gas depletion times, more compact galaxy sizes, and steeper metallicity gradients at the outskirts of the galaxies. These changes in galaxy properties can help disentangle altDM signatures from a range of astrophysical uncertainties. Meanwhile, it is the first time that altDM models have been studied in RHD simulations of galaxy formation. We uncover significant systematic uncertainties in reionization assumptions on the faint-end luminosity function. This underscores the necessity of accurately modeling the small-scale morphology of reionization in making predictions for the low-mass galaxy population. Upcoming James Webb Space Telescope imaging surveys of deep lensed fields hold potential for uncovering the faint low-mass galaxy population, which could provide constraints on altDM models.
Helical and non-helical large-scale dynamos in thin accretion discs
Authors: Zhou Hongzhe 
Published: November 2023

ABSTRACT
The dynamics of accreting and outgoing flows around compact objects depends crucially on the strengths and configurations of the magnetic fields therein, especially of the large-scale fields that remain coherent beyond turbulence scales. Possible origins of these large-scale magnetic fields include flux advection and disc dynamo actions. However, most numerical simulations have to adopt an initially strong large-scale field rather than allow them to be self-consistently advected or amplified, due to limited computational resources. The situation can be partially cured by using sub-grid models where dynamo actions only reachable at high resolutions are mimicked by artificial terms in low-resolution simulations. In this work, I couple thin-disc models with local shearing-box simulation results to facilitate more realistic sub-grid dynamo implementations. For helical dynamos, detailed spatial profiles of dynamo drivers inferred from local simulations are used, and the non-linear quenching and saturation is constrained by magnetic helicity evolution. In the inner disc region, saturated fields have dipole configurations and the plasma β reaches ≃0.1 to 100, with correlation lengths ≃h in the vertical direction and ≃10 h in the radial direction, where h is the disc scale height. The dynamo cycle period is ≃40 orbital time scale, compatible with previous global simulations. Additionally, I explore two dynamo mechanisms which do not require a net kinetic helicity and have only been studied in shearing-box set-ups. I show that such dynamos are possible in thin accretion discs, but produce field configurations that are incompatible with previous results. I discuss implications for future general-relativistic magnetohydrodynamics simulations.
Astroclimatic parameters characterization at lenghu site with ERA5 products
Authors: Bi Cuicui , Qing Chun , Qian Xianmei , Zhu Wenyue , Luo Tao , Li Xuebin , Cui Shengcheng , Weng Ningquan 
Published: November 2023

ABSTRACT
Atmospheric turbulence and wind speed distributions are essential in determining the quality of astronomical sites and implementing adaptive optics systems. In this study, the optical turbulence with a general turbulence model and the wind speed characteristics at Lenghu are investigated by employing the 21-yr European Centre for Medium-Range Weather Forecasts’ fifth set of reanalysis (ERA5) data. The vertical distributions and seasonal behaviours of the wind speed and atmospheric turbulence are analysed. The wind speed values at 200 hPa pressure level (V200) are low in spring and summer except for June, and high in autumn and winter. The highest and lowest values of V200 at Lenghu are 39.93 m s−1 in September and 27.48 m s−1 in April, respectively. Additionally, atmospheric conditions are relatively stable above 20 km throughout the year. The locations of the peaks in the $C_n^2$ profiles correspond to the tropopause and the jet wind stream regions at the Lenghu site. Furthermore, the median seeing value from ERA5 is 0.72 arcsec, generally consistent with the statistically measured value of 0.75 arcsec. Moreover, the astronomical parameters (r0, θAO, and τAO) were initially provided at the Lenghu site. The median values of r0, ε, θAO, and τAO are 15.17 cm, 0.72 arcsec, 1.19 arcsec, and 2.83 ms, respectively, thus providing the potential reference for astronomical applications.
J1046+4047: an extremely low-metallicity dwarf star-forming galaxy with O32 = 57
Authors: Izotov Y I , Thuan T X , Guseva N G 
Published: November 2023

ABSTRACT
Using the optical spectrum obtained with the Kitt Peak Ohio State Multi-Object Spectrograph mounted on the Apache Point Observatory 3.5 m Telescope and the Sloan Digital Sky Survey spectrum, we study the properties of one of the most metal-poor dwarf star-forming galaxies (SFGs) in the local Universe, J1046+4047. The galaxy, with a redshift z = 0.04874, was selected from the Data Release 16 of the SDSS. Its properties are among the most extreme for SFGs in several ways. The oxygen abundance 12 + log(O/H) = 7.082 ± 0.016 in J1046+4047 is among the lowest ever observed. With an absolute magnitude Mg = −16.51 mag, a low stellar mass M⋆ = 1.8 × 106 M⊙, and a very low mass-to-light ratio M⋆/Lg ∼ 0.0029 (in solar units), J1046+4047 has a very high specific star formation rate sSFR ∼ 430 Gyr−1, indicating very active ongoing star formation. Another striking feature of J1046+4047 is that it possesses a ratio O32 = I([O iii] λ5007)/I([O ii] λ3727) ∼ 57. Using this extremely high O32, we have confirmed and improved the strong-line calibration for the determination of oxygen abundances in the most metal-deficient galaxies, in the range 12 + log(O/H) ≲ 7.65. This improved method is applicable for all galaxies with O32 ≤ 60. We find the H α emission line in J1046+4047 to be enhanced by some non-recombination processes and thus cannot be used for the determination of interstellar extinction.
Physical properties of the eclipsing binary KIC 9851944 and analysis of its tidally perturbed p- and g-mode pulsations
Authors: Jennings Z , Southworth J , Pavlovski K , Van Reeth T 
Published: November 2023

ABSTRACT
Stars that are both pulsating and eclipsing offer an important opportunity to better understand many of the physical phenomena that occur in stars, because it is possible to measure the pulsation frequencies of stars for which the masses and radii are known precisely and accurately. KIC 9851944 is a double-lined detached eclipsing binary containing two F-stars which show both pressure and gravity mode pulsations. We present an analysis of new high-resolution spectroscopy of the system and high-quality light curves from the Kepler and TESS space missions. We determine the masses and effective temperatures of the stars to 0.6 per cent precision, and their radii to 1.0 and 1.5 per cent precision. The secondary component is cooler, but larger and more massive than the primary so is more evolved; both lie inside the δ Scuti and γ Doradus instability strips. We measure a total of 133 significant pulsation frequencies in the light curve, including 14 multiplets that each contain between 3 and 19 frequencies. We find evidence for tidal perturbations to some of the p and g modes, attribute a subset of the frequencies to either the primary or secondary star, and measure a buoyancy radius and near-core rotational frequency for the primary component. KIC 9851944 is mildly metal-rich and MIST isochrones from the MESA evolutionary code agree well with the observed properties of the system for an age of 1.25 Gyr.
The contribution of supermassive black holes in stripped nuclei to the supermassive black hole population of UCDs and galaxy clusters
Authors: Mayes Rebecca J , Drinkwater Michael J , Pfeffer Joel , Baumgardt Holger 
Published: November 2023

ABSTRACT
We use the hydrodynamic EAGLE simulation to predict the numbers and masses of supermassive black holes in remnant nuclei of disrupted galaxies (stripped nuclei) and compare these to confirmed measurements of black holes in observed ultra-compact dwarf galaxies (UCDs). We find that black holes in stripped nuclei are consistent with the numbers and masses of those in observed UCDs. Approximately 50 per cent of stripped nuclei with M &gt; 2 × 106 M⊙ should contain supermassive black holes. We further calculate how the presence of a black hole increases the dynamical mass of a stripped nucleus via the mass elevation ratio, Ψ defined as the ratio of the kinematically derived mass to the expected mass from stellar population synthesis. We find Ψsim$= 1.51^{+0.06}_{-0.04}$ for M &gt; 107 M⊙ stripped nuclei, consistent with that of observed UCDs, which have Ψobs = 1.7 ± 0.2 above M &gt; 107 M⊙. We also find that the mass elevation ratios of stripped nuclei with supermassive black holes can explain the observed number of UCDs with elevated mass-to-light ratios. Finally, we predict the relative number of massive black holes in stripped nuclei and galaxy nuclei and find that stripped nuclei should increase the number of black holes in galaxy clusters by 30 − 100 per cent, depending on the black hole occupation fraction of low-mass galaxies. We conclude that the population of supermassive black holes in UCDs represents a large and unaccounted-for portion of supermassive black holes in galaxy clusters.
Retrieving the 21-cm signal from the Epoch of Reionization with learnt Gaussian process kernels
Authors: Mertens Florent G , Bobin Jérôme , Carucci Isabella P 
Published: November 2023

ABSTRACT
Direct detection of the Cosmic Dawn and Epoch of Reionization via the redshifted 21-cm line of neutral Hydrogen will have unprecedented implications for studying structure formation in the early Universe. This exciting goal is challenged by the difficulty of extracting the faint 21-cm signal buried beneath bright astrophysical foregrounds and contaminated by numerous systematics. Here, we focus on improving the Gaussian Process Regression (GPR) signal separation method originally developed for LOFAR observations. We address a key limitation of the current approach by incorporating covariance prior models learnt from 21-cm signal simulations using variational autoencoder (VAE) and interpolatory autoencoder (IAE). Extensive tests are conducted to evaluate GPR, VAE–GPR, and IAE–GPR in different scenarios. Our findings reveal that the new method outperforms standard GPR in component separation tasks. Moreover, the improved method demonstrates robustness when applied to signals not represented in the training set. It also presents a certain degree of resilience to data systematics, highlighting its ability to effectively mitigate their impact on the signal recovery process. However, our findings also underscore the importance of accurately characterizing and understanding these systematics to achieve successful detection. Our generative approaches provide good results even with limited training data, offering a valuable advantage when a large training set is not feasible. Comparing the two algorithms, IAE–GPR shows slightly higher fidelity in recovering power spectra compared to VAE–GPR. These advancements highlight the strength of generative approaches and optimize the analysis techniques for future 21-cm signal detection at high redshifts.
Evolution of helium triplet transits of close-in gas giants orbiting K dwarfs
Authors: Allan Andrew P , Vidotto Aline A , Villarreal D’Angelo Carolina , Dos Santos Leonardo A , Driessen Florian A 
Published: November 2023

ABSTRACT
Atmospheric escape in exoplanets has traditionally been observed using hydrogen Lyman-α and Hα transmission spectroscopy, but more recent detections have utilized the metastable helium triplet at 1083 nm. Since this feature is accessible from the ground, it offers new possibilities for studying atmospheric escape. Our goal is to understand how the observability of escaping helium evolves during the lifetime of a highly irradiated gas giant. We extend our previous work on 1D self-consistent hydrodynamic escape from hydrogen-only atmospheres as a function of planetary evolution to the first evolution-focused study of escaping hydrogen–helium atmospheres. Additionally, using these novel models we perform helium triplet transmission spectroscopy. We adapt our previous hydrodynamic escape model to now account for both hydrogen and helium heating and cooling processes and simultaneously solve for the population of helium in the triplet state. To account for the planetary evolution, we utilize evolving predictions of planetary radii for a close-in 0.3 MJup gas giant and its received stellar flux in X-ray, hard and soft extreme-ultraviolet (UV), and mid-UV wavelength bins assuming a K-dwarf stellar host. We find that the helium triplet signature diminishes with evolution. Our models suggest that young (≲ 150 Myr), close-in gas giants (∼1 to 2 RJup) should produce helium 1083 nm transit absorptions of $\sim 4~{{\ \rm per\ cent}}$ or $\sim 7~{{\ \rm per\ cent}}$, for a slow- or fast-rotating K dwarf, respectively, assuming a 2 per cent helium abundance.
Primordial black holes as near-infrared background sources
Authors: Manzoni D , Ziparo F , Gallerani S , Ferrara A 
Published: November 2023

ABSTRACT
The near-infrared background (NIRB) is the collective light from unresolved sources observed in the band 1–10 $\rm{\mu m}$. The measured NIRB angular power spectrum on angular scales θ ≳ 1 arcmin exceeds by roughly two order of magnitudes predictions from known galaxy populations. The nature of the sources producing these fluctuations is still unknown. Here, we test primordial black holes (PBHs) as sources of the NIRB excess. Considering PBHs as a cold dark matter (DM) component, we model the emission of gas accreting on to PBHs in a cosmological framework. We account for both accretion in the intergalactic medium (IGM) and DM haloes. We self-consistently derive the IGM temperature evolution, considering ionization and heating due to X-ray emission from PBHs. Besides lambda cold DM, we consider a model that accounts for the modification of the linear matter power spectrum due to the presence of PBHs; we also explore two PBH mass distributions, i.e. a δ-function and a lognormal distribution. For each model, we compute the mean intensity and the angular power spectrum of the NIRB produced by PBHs with mass 1–$10^3~\rm M_{\odot }$. In the limiting case in which the entirety of DM is made of PBHs, the PBH emission contributes &lt;1 per cent to the observed NIRB fluctuations. This value decreases to &lt;0.1 per cent if current constraints on the abundance of PBHs are taken into account. We conclude that PBHs are ruled out as substantial contributors to the NIRB.
XQz5: a new ultraluminous z ∼ 5 quasar legacy sample
Authors: Lai Samuel , Onken Christopher A , Wolf Christian , Bian Fuyan , Fan Xiaohui 
Published: November 2023

ABSTRACT
Bright quasar samples at high redshift are useful for investigating active galactic nuclei evolution. In this study, we describe XQz5, a sample of 83 ultraluminous quasars in the redshift range 4.5 &lt; z &lt; 5.3 with optical and near-infrared spectroscopic observations, with unprecedented completeness at the bright end of the quasar luminosity function. The sample is observed with the Southern Astrophysical Research Telescope, the Very Large Telescope, and the Australian National University 2.3 m Telescope, resulting in a high-quality, moderate-resolution spectral atlas of the brightest known quasars within the redshift range. We use established virial mass relations to derive the black hole masses by measuring the observed Mg ii λ2799 Å emission line and we estimate the bolometric luminosity with bolometric corrections to the ultraviolet continuum. Comparisons to literature samples show that XQz5 bridges the redshift gap between other X-shooter quasar samples, XQ-100 and XQR-30, and is a brighter sample than both. Luminosity-matched lower redshift samples host more massive black holes, which indicate that quasars at high redshift are more active than their counterparts at lower redshift, in concordance with recent literature.
Developing Clinical Perspectives: Reflections on Student and Teacher Experiences of an Undergraduate Music Therapy Course
Authors: Devlin Kerry , Lukacs Karrin , Simon-Levine Zoe , Mette Ridder Hanne , Meadows Anthony 
Published: November 2023

Abstract
Centered in the Scholarship of Teaching and Learning, we describe and reflect upon student and teacher experiences of an undergraduate music therapy course in which students are introduced to two core clinical perspectives derived from the music therapy literature: decision-making and case formulation. Guiding the reader through four interrelated course phases, we discuss key content areas, challenges students encountered, and the ways the course instructors engaged with and worked through these challenges. Key learning outcomes are identified, specifically focusing on the importance of 1) teaching multiple perspectives early in a music therapy curriculum, 2) prerequisite knowledge, 3) musical competence, and 4) an integrated curriculum. In doing so, we advocate for an integral perspective to clinical practice, through which students develop the ability to locate themselves and shift perspectives in service of their clients.
Diatonic Voice-Leading Transformations
Authors: Frederick Leah 
Published: November 2023

Abstract
This article draws on the mathematical approaches of Tymoczko (2011) and Hook (2008) to construct a transformational space of closed-position diatonic triads. The group acts on a set of twenty-one objects: the seven diatonic triads differentiated by the three closed-position inversions. After constructing the transformation group as an abstract voice-leading space, I interpret the system as an instrumental space (De Souza 2017) that captures the chord shapes required to play triadic progressions on a keyboard. This emphasis on the space’s ability to capture such chord shapes leads to generalizations of the system that explore interactions between voice leading and chord spacing using geometric and diatonic theory.
The Reactome Pathway Knowledgebase 2024
Authors: Milacic Marija , Beavers Deidre , Conley Patrick , Gong Chuqiao , Gillespie Marc , Griss Johannes , Haw Robin , Jassal Bijay , Matthews Lisa , May Bruce , Petryszak Robert , Ragueneau Eliot , Rothfels Karen , Sevilla Cristoffer , Shamovsky Veronica , Stephan Ralf , Tiwari Krishna , Varusai Thawfeek , Weiser Joel , Wright Adam , Wu Guanming , Stein Lincoln , Hermjakob Henning , D’Eustachio Peter 
Published: November 2023

Abstract
The Reactome Knowledgebase (https://reactome.org), an Elixir and GCBR core biological data resource, provides manually curated molecular details of a broad range of normal and disease-related biological processes. Processes are annotated as an ordered network of molecular transformations in a single consistent data model. Reactome thus functions both as a digital archive of manually curated human biological processes and as a tool for discovering functional relationships in data such as gene expression profiles or somatic mutation catalogs from tumor cells. Here we review progress towards annotation of the entire human proteome, targeted annotation of disease-causing genetic variants of proteins and of small-molecule drugs in a pathway context, and towards supporting explicit annotation of cell- and tissue-specific pathways. Finally, we briefly discuss issues involved in making Reactome more fully interoperable with other related resources such as the Gene Ontology and maintaining the resulting community resource network.