bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Rise and Fall of the Eclipsing Binary HS Hydrae
Authors: Davenport James. R. A. , Windemuth Diana , Warmbein Karen , Howard Erin L. , Klein Courtney , Birky Jessica 
Published: October 2021

Abstract
HS Hydrae is a short period eclipsing binary (P
orb = 1.57 day) that belongs to a rare group of systems observed to have rapidly changing inclinations. This evolution is due to a third star on an intermediate orbit, and results in significant differences in eclipse depths and timings year to year. Zasche & Paschke revealed that HS Hydrae’s eclipses were rapidly fading from view, predicting they would cease around 2022. Using 25 days of photometric data from Sector 009 of the Transiting Exoplanet Survey Satellite (TESS), we find that the primary eclipses for HS Hydrae were only 0.00173 ± 0.00007 mag in depth in March 2019. This data from TESS likely represents the last eclipses detected from HS Hydrae. We also searched the Digitization of the Harvard Astronomical Plate Collection archive for historic data from the system. With a total baseline of over 125 yr, this unique combination of data sets—from photographic plates to precision space-based photometry—allows us to trace the emergence and decay of eclipses from HS Hydrae, and further constrain its evolution. Recent TESS observations from Sector 035 confirm that eclipses have ceased for HS Hya, and we estimate they will begin again in 2195.
Metallicity Estimation of RR Lyrae Stars From Their I-Band Light Curves
Authors: Dékány István , Grebel Eva K. , Pojmański Grzegorz 
Published: October 2021

Abstract
We have revisited the problem of metallicity prediction of RR Lyrae stars from their near-infrared light curves in the Cousins I wave band. Our study is based on high-quality time series photometry and state-of-the-art high-resolution spectroscopic abundance measurements of 80 fundamental-mode (RRab) and 24 first-overtone (RRc) stars, spanning ∼[−2.7, +0.18] dex and ∼[−3, −0.5] dex ranges, respectively. Employing machine-learning methods, we investigated various light-curve representations and regression models to identify their optimal form for our objective. Accurate new empirical relations between the [Fe/H] iron abundance and the light-curve parameters have been obtained using Bayesian regression for both RRab and RRc stars with mean absolute prediction errors of 0.16 dex and 0.18 dex, respectively. We found that earlier I-band [Fe/H] estimates had a systematic positive bias of up to ∼0.4 dex in the metal-poor regime. Our new predictive models were deployed on large ensembles of RR Lyrae stars to obtain photometric metallicity distribution functions (MDFs) for various old stellar populations in and around the Milky Way. We find that the mode of the old bulge component’s MDF is approximately −1.4 dex, in remarkable agreement with the latest spectroscopic result. Furthermore, we derive MDF modes of −1.83, −2.13, and −1.77 dex for the Large and Small Magellanic Clouds and the Sagittarius dwarf galaxy, respectively.
The GOGREEN Survey: Evidence of an Excess of Quiescent Disks in Clusters at 1.0 < z < 1.4
Authors: Chan Jeffrey C. C. , Wilson Gillian , Balogh Michael , Rudnick Gregory , van der Burg Remco F. J. , Muzzin Adam , Webb Kristi A. , Biviano Andrea , Cerulo Pierluigi , Cooper M. C. , De Lucia Gabriella , Demarco Ricardo , Forrest Ben , Jablonka Pascale , Lidman Chris , McGee Sean L. , Nantais Julie , Old Lyndsay , Pintos-Castro Irene , Poggianti Bianca , Reeves Andrew M. M. , Vulcani Benedetta , Yee Howard K. C. , Zaritsky Dennis 
Published: October 2021

Abstract
We present the results of the measured shapes of 832 galaxies in 11 galaxy clusters at 1.0 < z < 1.4 from the GOGREEN survey. We measure the axis ratio (q), the ratio of the minor to the major axis, of the cluster galaxies from near-infrared Hubble Space Telescope imaging using Sérsic profile fitting and compare them with a field sample. We find that the median q of both star-forming and quiescent galaxies in clusters increases with stellar mass, similar to the field. Comparing the axis ratio distributions between clusters and the field in four mass bins, the distributions for star-forming galaxies in clusters are consistent with those in the field. Conversely, the distributions for quiescent galaxies in the two environments are distinct, most remarkably in

10.1
≤
log
(
M

/

M

⊙

)
<
10.5

where clusters show a flatter distribution, with an excess at low q. Modelling the distribution with oblate and triaxial components, we find that the cluster and field sample difference is consistent with an excess of flattened oblate quiescent galaxies in clusters. The oblate population contribution drops at high masses, resulting in a narrower q distribution in the massive population than at lower masses. Using a simple accretion model, we show that the observed q distributions and quenched fractions are consistent with a scenario where no morphological transformation occurs for the environmentally quenched population in the two intermediate-mass bins. Our results suggest that environmental quenching mechanism(s) likely produce a population that has a different morphological mix than those resulting from the dominant quenching mechanism in the field.
An Improved Near-infrared Spectrum of the Archetype Y Dwarf WISEP J182831.08+265037.8
Authors: Cushing Michael C. , Schneider Adam C. , Kirkpatrick J. Davy , Morley Caroline V. , Marley Mark S. , Gelino Christopher R. , Mace Gregory N. , Wright Edward L. , Eisenhardt Peter R. , Skrutskie Michael F. , Marsh Kenneth A. 
Published: October 2021

Abstract
We present a Hubble Space Telescope/Wide-Field Camera 3 near-infrared spectrum of the archetype Y dwarf WISEP 182831.08+265037.8. The spectrum covers the 0.9–1.7 μm wavelength range at a resolving power of λ/Δλ ≈ 180 and is a significant improvement over the previously published spectrum because it covers a broader wavelength range and is uncontaminated by light from a background star. The spectrum is unique for a cool brown dwarf in that the flux peaks in the Y, J, and H bands are of near equal intensity in units of f

λ
. We fail to detect any absorption bands of NH3 in the spectrum, in contrast to the predictions of chemical equilibrium models, but tentatively identify CH4 as the carrier of an unknown absorption feature centered at 1.015 μm. Using previously published ground- and spaced-based photometry, and using a Rayleigh–Jeans tail to account for flux emerging longward of 4.5 μm, we compute a bolometric luminosity of

log
(

L

bol

/



⊙

N

)
=
−
6.50
±
0.02

, which is significantly lower than previously published results. Finally, we compare the spectrum and photometry to two sets of atmospheric models and find that the best overall match to the observed properties of WISE 1828+2650 is a ∼1 Gyr old binary composed of two T
eff ∼ 325 K, ∼5 M
Jup brown dwarfs with subsolar [C/O] ratios.
Alfvén Number for the Richtmyer–Meshkov Instability in Magnetized Plasmas
Authors: Sano Takayoshi 
Published: October 2021

Abstract
The magnetohydrodynamical (MHD) evolution of the Richtmyer–Meshkov instability (RMI) is investigated using two-dimensional MHD simulations. The RMI is suppressed by a strong magnetic field, whereas the RMI amplifies an ambient magnetic field by many orders of magnitude if the seed field is weak. We have found that the suppression and amplification processes can be evaluated continuously along with the amplitude of the Alfvén number R

A
, which is defined as the ratio of the linear growth velocity of the RMI to the Alfvén speed at the interface. When the Alfvén number is less than unity, the Lorentz force acting on the fluid mitigates the unstable motion of the RMI significantly, and the interface oscillates stably in this limit. If R

A
≳ 1, on the other hand, the surface modulation increases due to the growth of the RMI. The maximum strength of the magnetic field is enhanced up to by a factor of R

A
. This critical feature is universal and independent of the initial Mach number of the incident shock, the Atwood number, corrugation amplitude, and even the direction of the initial magnetic field.
Enhanced Localization of Transients Based on a Novel Cross-correlation Method
Authors: Xiao S. , Xiong S. L. , Zhang S. N. , Song L. M. , Lu F. J. , Huang Y. , Cai C. , Yi Q. B. , Song X. Y. , Chen W. , Ge M. Y. , Liu C. Z. , Li X. B. , Li C. K. , Zhao Y. 
Published: October 2021

Abstract
Locating gamma-ray transients including gamma-ray bursts (GRBs) and soft gamma repeater (SGR) bursts is of great importance in multi-messenger and multi-wavelength astronomy, such as guiding optical and radio follow-up observations and evaluating the association of a GRB with a gravitational wave or an SGR with a galaxy or fast radio burst (FRB). A time delay (or triangulation) method with multiple missions has been utilized to localize GRBs since their discovery in the 1970s. In this paper, we propose to use the Modified Cross-correlation Function (called Li-CCF hereafter) to derive the accurate time delay from the high time resolution light curves recorded by GRB detectors. This method has been extensively verified with simulation and a sample of GRBs and SGRs with precise positions, using event-by-event data (TTE or Evt data) of Insight-HXMT/HE, Fermi/GBM, Swift/BAT, and GECAM. We find that the 1σ uncertainty (annulus half-width) can be less than 0.3 degrees despite the relatively short distance between these satellites. We note that the localization error given by Li-CCF can be reduced by several times compared with the traditional CCF method or the Fermi/GBM-alone localization, depending on the timing, spectral lag and direction of the GRB, and the distance and number of satellites used. Finally, systematic errors of this time delay method, including the effect of GRB spectral lags and background variation in light curves, have been studied in detail and several improvements have been proposed to deal with those effects.
EvryFlare. iv. Detection of Periodicity in Flare Occurrence from Cool Stars with TESS
Authors: Howard Ward S. , Law Nicholas M. 
Published: October 2021

Abstract
Phased flaring, or the periodic occurrence of stellar flares, may probe electromagnetic star−planet interaction (SPI), binary interaction, or magnetic conditions in spots. For the first time, we explore flare periodograms for a large sample of flare stars to identify periodicity due to magnetic interactions with orbiting companions, magnetic reservoirs, or rotational phase. Previous large surveys have explored periodicity at the stellar rotation period, but we do not assume periods must correspond with rotation in this work. Two-minute TESS light curves of 284 cool stars are searched for periods of 1–10 days using two newly developed periodograms. Because flares are discrete events in noisy and incomplete data, typical periodograms are not well suited to detect phased flaring. We construct and test a new Bayesian likelihood periodogram and a modified Lomb–Scargle periodogram. We find six candidates with a false-alarm probability below 1%. Three targets are ≥3σ detections of flare periodicity; the others are plausible candidates that cannot be individually confirmed. Periods range from 1.35 to 6.7 days and some, but not all, correlate with the stellar rotation period or its 1/2 alias. Periodicity from two targets may persist from TESS Cycle 1 into Cycle 3. The periodicity does not appear to persist for the others. Long-term changes in periodicity may result from the spot evolution observed from each candidate, which suggests magnetic conditions play an important role in sustaining periodicity.
Spectral Signature of Mass Outflow in the Two Component Advective Flow Paradigm
Authors: Mondal Santanu , Chakrabarti Sandip K. 
Published: October 2021

Abstract
Outflows are common in many astrophysical systems. In the Two Component Advective Flow (TCAF) paradigm, which is essentially a generalized Bondi flow including rotation, viscosity, and cooling effects, the outflow originates in the hot, puffed up, post-shock region at the inner edge of the accretion disk. We consider this region to be the base of the jet carrying away matter with a high velocity. In this paper, we study the spectral properties of black holes using TCAF that includes also a jet (JeTCAF) in the vertical direction of the disk plane. Soft photons from the Keplerian disk are up-scattered by the post-shock region as well as by the base of the jet and are emitted as hard radiation. We also include the bulk motion Comptonization effect by the diverging flow of the jet. Our self-consistent accretion-ejection solution shows how the spectrum from the base of the jet varies with accretion rates, geometry of the flow, and the collimation factor of the jet. We apply the solution to a jetted candidate GS 1354-64 to estimate its mass outflow rate and the geometric configuration of the flow during the 2015 outburst observed by NuSTAR. The estimated mass outflow to mass inflow rate is

0.12

−
0.03

+
0.02

. From the model-fitted accretion rates, shock compression ratio, and the energy spectral index, we identify the presence of hard and intermediate spectral states of the outburst. Our model-fitted jet collimation factor (f
col) is found to be

0.47

−
0.09

+
0.09

.
On the Crystallinity of Silicate Dust in Evolving Protoplanetary Disks due to Magnetically Driven Disk Winds
Authors: Arakawa Sota , Matsumoto Yuji , Honda Mitsuhiko 
Published: October 2021

Abstract
We present a novel mechanism for the outward transport of crystalline dust particles: the outward radial drift of pebbles. A dust-ring structure is frequently observed in protoplanetary disks. One of the plausible mechanisms for the formation of dust rings is the accumulation of pebbles around the pressure maximum, which is formed by the mass loss due to magnetically driven disk winds. Due to magnetically driven disk winds, dust particles in evolving protoplanetary disks can migrate outwardly from the crystallization front to the pressure maximum by radial drift. We found that the outward radial drift process can transport crystalline dust particles efficiently when the radial drift timescale is shorter than the advection timescale. Our model predicts that the crystallinity of silicate dust particles could be as high as 100% inside the dust-ring position.
Minute-timescale Variability in the X-ray Emission of the Highest Redshift Blazar*
Authors: Moretti Alberto , Ghisellini Gabriele , Caccianiga Alessandro , Belladitta Silvia , Della Ceca Roberto , Ighina Luca , Sbarrato Tullia , Severgnini Paola , Spingola Cristiana 
Published: October 2021

Abstract
We report on two Chandra observations of the quasar PSO J0309+27, the most distant blazar observed so far (z = 6.1), performed eight months apart, in 2020 March and November. Previous Swift-XRT observations showed that this object is one of the brightest X-ray sources beyond redshift 6.0 ever observed so far. This new dataset confirmed the high flux level and unveiled a spectral change that occurred on a very short timescale (250 s rest frame), caused by a significant softening of the emission spectrum. This kind of spectral variability, on such a short interval, has never been reported in the X-ray emission of a flat-spectrum radio quasar. A possible explanation for this is given by the emission produced by the inverse Compton scatter of the quasar UV photons by the cold electrons present in a fast shell moving along the jet. Although this bulk Comptonization emission should be an unavoidable consequence of the standard leptonic jet model, this would be the first time that it has been observed.
Discovery of Transition from Marginally Stable Burning to Unstable Burning after a Superburst in Aql X-1
Authors: Li Zhaosheng , Pan Yuanyue , Falanga Maurizio 
Published: October 2021

Abstract
Superbursts are long duration, rare, and extremely energetic thermonuclear explosions of neutron star low-mass X-ray binaries (NS LMXBs), which are proposed to be due to unstable carbon ignition. We report the superburst properties and consequences from Aql X–1 observed by the Neutron Star Interior Composition Explorer (NICER), the Monitor of All-sky X-ray Image, Swift, and Insight Hard X-ray Modulation Telescope (Insight-HXMT) on the MJD 59130.7. We found two faint type I X-ray bursts 9.44 days after the superburst with a short recurrence time of 7.6 minutes, which is the most accurate measurement of the quenching time in all NS LMXBs with observed superbursts. We also discovered mHz quasi-periodic oscillations in the frequency range 2.7–11.3 mHz immediately after the superburst, before and after the resumption of the first type I X-ray burst from NICER, Swift, and Insight-HXMT observations. For the first time, we observed the transition from superburst, via marginally stable burning to unstable burning in NS LMXBs. We compared the quenching time and the recurrence time of type I X-ray bursts with simulations.
A New Catalog of Asymptotic Giant Branch Stars in Our Galaxy
Authors: Suh Kyung-Won 
Published: October 2021

Abstract
We present a new catalog of 11,209 O-rich asymptotic giant branch (AGB) stars and 7172 C-rich AGB stars in our Galaxy, identifying more AGB stars in the bulge component and considering more visual carbon stars. For each object, we cross-identify the Infrared Astronomical Satellite (IRAS), AKARI, Midcourse Space Experiment, Wide-field Infrared Survey Explorer (WISE), Two-Micron All-Sky Survey, and American Association of Variable Star Observers counterparts. We present the new catalog in two parts: one is based on the IRAS PSC for brighter or more isolated objects; the other one is based on the ALLWISE source catalog for less bright objects or objects in crowded regions. We present various infrared two-color diagrams (2CDs) for the sample stars. We find that the theoretical dust shell models can roughly explain the observations of AGB stars on the various IR 2CDs. We investigate IR properties of SiO and OH maser emission sources in the catalog. For Mira variables in the sample stars, we find that the IR colors get redder for longer pulsation periods. We also study infrared variability of the sample stars using the WISE photometric data in the last 12 yr: the ALLWISE multiepoch data and the Near-Earth Object WISE Reactivation 2021 data release. We generate light curves using the WISE data at W1 and W2 bands and compute the Lomb–Scargle periodograms for all of the sample stars. From the WISE light curves, we have found useful variation parameters for 3710 objects in the catalog, for which periods were either known or unknown in previous works.
Galaxy Rotation Curves Disfavor Traditional and Self-interacting Dark Matter Halos, Preferring a Disk Component or Einasto Function
Authors: Loizeau Nicolas , Farrar Glennys R. 
Published: October 2021

Abstract
We use the galaxy rotation curves in the SPARC database to compare nine different dark matter (DM) and modified gravity models on an equal footing, paying special attention to the stellar mass-to-light ratios. We compare three noninteracting DM models: a self-interacting DM model, two hadronically interacting DM models, and three modified Newtonian dynamics type models, modified Newtonian dynamics (MOND), a radial acceleration relation, and a maximal-disk model. The models with DM–gas interactions generate a disky component in the DM, which significantly improves the fits to the rotation curves compared to all other models except an Einasto halo; the MOND-type models give significantly worse fits.
When Hot Meets Cold: Post-flare Coronal Rain
Authors: Ruan Wenzhi , Zhou Yuhao , Keppens Rony 
Published: October 2021

Abstract
Most solar flares demonstrate a prolonged, hour-long post-flare (or gradual) phase, characterized by arcade-like, post-flare loops (PFLs) visible in many extreme ultraviolet (EUV) passbands. These coronal loops are filled with hot (∼30 MK) and dense plasma that evaporated from the chromosphere during the impulsive phase of the flare, and they very gradually recover to normal coronal density and temperature conditions. During this gradual cooling down to ∼1 MK regimes, much cooler (∼0.01 MK) and denser coronal rain is frequently observed inside PFLs. Understanding PFL dynamics in this long-duration, gradual phase is crucial to the entire corona–chromosphere mass and energy cycle. Here we report a simulation in which a solar flare evolves from pre-flare, over the impulsive phase all the way into its gradual phase, which successfully reproduces post-flare coronal rain. This rain results from catastrophic cooling caused by thermal instability, and we analyze the entire mass and energy budget evolution driving this sudden condensation phenomenon. We find that the runaway cooling and rain formation also induces the appearance of dark post-flare loop systems, as observed in EUV channels. We confirm and augment earlier observational findings, suggesting that thermal conduction and radiative losses alternately dominate the cooling of PFLs.
Formation of the First Two Black Hole–Neutron Star Mergers (GW200115 and GW200105) from Isolated Binary Evolution
Authors: Broekgaarden Floor S. , Berger Edo 
Published: October 2021

Abstract
In this work we study the formation of the first two black hole–neutron star (BHNS) mergers detected in gravitational waves (GW200115 and GW200105) from massive stars in wide isolated binary systems—the isolated binary evolution channel. We use 560 BHNS binary population synthesis model realizations and show that the system properties (chirp mass, component masses, and mass ratios) of both GW200115 and GW200105 match predictions from the isolated binary evolution channel. We also show that most model realizations can account for the local BHNS merger rate densities inferred by LIGO–Virgo. However, to simultaneously also match the inferred local merger rate densities for BHBH and NSNS systems we find we need models with moderate kick velocities (σ ≲ 102 km s−1) or high common-envelope efficiencies (α
CE ≳ 2) within our model explorations. We conclude that the first two observed BHNS mergers can be explained from the isolated binary evolution channel for reasonable model realizations.
Morphological, calorific and nutritive characteristics of 656 freshwater invertebrates taxa
Authors: Moreau Axelle , Dupuy Christine , Bocher Pierrick , Farau Sébastien 
Published: October 2021

The Freshwater Animal Diversity Assessment (FADA) project estimated that freshwater animal species represent 9.5% of the 1.2 million species described. Knowing that freshwater represents only 0.01% of the earth's surface, these wetlands are suitable habitats for a great part of the world's total biodiversity. However, it has been shown that there is a lack of knowledge on these species, including freshwater invertebrates. Nevertheless, they play a key role in the majority of freshwater ecosystems and in their foodweb networks. Freshwater invertebrates are the food resource of many species, such as fish and birds. The knowledge of their morphological, energetic and nutritive characteristics allows a better understanding of their selection by predators (size, energy intake etc.), but also leads to the improvement of wetland management. Although information about freshwater invertebrates exists in literature, they are generally heterogeneous, dispersed and difficult to collect. To facilitate the accessibility of these data and, thus, optimise and accelerate research projects including freshwater invertebrates, we propose a literature review describing 14 morphological and nutritive characteristics (size, dry weight, gross energy, crude protein etc.) for 656 taxa of freshwater invertebrates.
This dataset is a review from 104 publications from 1935 to 2020, compiling 14 characteristics when available (size, dry weight, gross energy, crude protein etc.) for 656 taxa of freshwater invertebrates.