bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Warm Gas in the Milky Way: The Kinematical Model of C iv and Its Connection to Si iv
Authors: Qu Zhijie , Lindley Ryan , Bregman Joel N. 
Published: January 2022

Abstract
We compose a 265-sight-line Milky Way C iv line-shape sample using the Hubble Space Telescope/Cosmic Origins Spectrograph archive, which is complementary to the existing Si iv samples. C iv has a higher ionization potential (47–64 eV) than Si iv (33–45 eV), so it also traces warm gas, which is roughly cospatial with Si iv. The spatial density distribution and kinematics of C iv are identical to those Si iv within ≈2σ. C iv is more sensitive to the warm gas density distribution at large radii with a higher element abundance. Applying the kinematical model to the C iv sample, we find two possible solutions of the density distribution, which are distinguished by the relative extension along the disk midplane and the normal-line direction. Both solutions can reproduce the existing sample and suggest a warm gas disk mass of

log
M
(

M

⊙

)
≈
8

and an upper limit of

log
M
(

M

⊙

)
<
9.3

within 250 kpc, which is consistent with Si iv. There is a decrease in the C iv/Si iv column density ratio from the Galactic center to the outskirts by 0.2–0.3 dex, which may suggest a phase transition or different ionization mechanisms for C iv and Si iv. Also, we find that the difference between C iv and Si iv is an excellent tracer of small-scale features, and we find a typical size of 5°–10° for possible turbulence within individual clouds (≈1 kpc).
Data-driven Expectations for Electromagnetic Counterpart Searches Based on LIGO/Virgo Public Alerts
Authors: Petrov Polina , Singer Leo P. , Coughlin Michael W. , Kumar Vishwesh , Almualla Mouza , Anand Shreya , Bulla Mattia , Dietrich Tim , Foucart Francois , Guessoum Nidhal 
Published: January 2022

Abstract
Searches for electromagnetic counterparts of gravitational-wave signals have redoubled since the first detection in 2017 of a binary neutron star merger with a gamma-ray burst, optical/infrared kilonova, and panchromatic afterglow. Yet, one LIGO/Virgo observing run later, there has not yet been a second, secure identification of an electromagnetic counterpart. This is not surprising given that the localization uncertainties of events in LIGO and Virgo’s third observing run, O3, were much larger than predicted. We explain this by showing that improvements in data analysis that now allow LIGO/Virgo to detect weaker and hence more poorly localized events have increased the overall number of detections, of which well-localized, gold-plated events make up a smaller proportion overall. We present simulations of the next two LIGO/Virgo/KAGRA observing runs, O4 and O5, that are grounded in the statistics of O3 public alerts. To illustrate the significant impact that the updated predictions can have, we study the follow-up strategy for the Zwicky Transient Facility. Realistic and timely forecasting of gravitational-wave localization accuracy is paramount given the large commitments of telescope time and the need to prioritize which events are followed up. We include a data release of our simulated localizations as a public proposal planning resource for astronomers.
Gamma-Ray Orbital Modulation of the Transitioning Millisecond Pulsar Binary XSS J12270–4859
Authors: An Hongjun 
Published: January 2022

Abstract
We report on gamma-ray orbital modulation of the transitioning MSP binary XSS J12270–4859 detected in the Fermi Large Area Telescope (LAT) data. We use long-term optical data taken with the XMM-Newton OM and the Swift UltraViolet Optical Telescope to inspect radio timing solutions that are limited to relatively short time intervals and find that extrapolation of the solutions aligns well with the phasing of the optical data over 15 yr. The Fermi-LAT data folded on the timing solutions exhibit significant modulation (p = 5 × 10−6) with a gamma-ray minimum at the inferior conjunction of the pulsar. Intriguingly, the source seems to show similar modulation in both the low-mass X-ray binary and the MSP states, implying that mechanisms for gamma-ray emission in the two states are similar. We discuss these findings and their implications using an intrabinary shock scenario.
Two Correlations with Enhancement Near the Proton Gyroradius Scale in Solar Wind Turbulence: Parker Solar Probe (PSP) and Wind Observations
Authors: Zhao G. Q. , Lin Y. , Wang X. Y. , Feng H. Q. , Wu D. J. , Kasper J. C. 
Published: January 2022

Abstract
Based on the Parker Solar Probe mission, this paper presents the observations of two correlations in solar wind turbulence near the Sun for the first time, demonstrating the clear existence of the following two correlations. One is positive correlation between the proton temperature and turbulent magnetic energy density. The other is negative correlation between the spectral index and magnetic helicity. It is found that the former correlation has a maximum correlation coefficient (CC) at the wavenumber k
ρ

p
≃ 0.5 (ρ

p
being the proton thermal gyroradius), and the latter correlation has a maximum absolute value of CC at k
ρ

p
≃ 1.8. In addition, investigations based on 11 yr of Wind observations reveal that the dimensionless wavenumbers (k
ρ

p
) corresponding to the maximum (absolute) values of CC remain nearly the same for different data sets. These results tend to suggest that the two correlations enhanced near the proton gyroradius scale would be a common feature of solar wind turbulence.
Three-dimensional Hybrid Simulation Results of a Variable Magnetic Helicity Signature at Proton Kinetic Scales
Authors: Vasquez Bernard J. , Markovskii Sergei A. , Smith Charles W. 
Published: January 2022

Abstract
Three-dimensional hybrid kinetic simulations are conducted with particle protons and warm fluid electrons. Alfvénic fluctuations initialized at large scales and with wavevectors that are highly oblique with respect to the background magnetic field evolve into a turbulent energy cascade that dissipates at proton kinetic scales. Accompanying the proton scales is a spectral magnetic helicity signature with a peak in magnitude. A series of simulation runs are made with different large-scale cross helicity and different initial fluctuation phases and wavevector configurations. From the simulations a so-called total magnetic helicity peak is evaluated by summing contributions at a wavenumber perpendicular to the background magnetic field. The total is then compared with the reduced magnetic helicity calculated along spacecraft-like trajectories through the simulation box. The reduced combines the helicity from different perpendicular wavenumbers and depends on the sampling direction. The total is then the better physical quantity to characterize the turbulence. On average the ratio of reduced to total is 0.45. The total magnetic helicity and the reduced magnetic helicity show intrinsic variability based on initial fluctuation conditions. This variability can contribute to the scatter found in the observed distribution of solar wind reduced magnetic helicity as a function of cross helicity.
Dark Energy Survey Year 3 Results: Measuring the Survey Transfer Function with Balrog
Authors: Everett S. , Yanny B. , Kuropatkin N. , Huff E. M. , Zhang Y. , Myles J. , Masegian A. , Elvin-Poole J. , Allam S. , Bernstein G. M. , Sevilla-Noarbe I. , Splettstoesser M. , Sheldon E. , Jarvis M. , Amon A. , Harrison I. , Choi A. , Hartley W. G. , Alarcon A. , Sánchez C. , Gruen D. , Eckert K. , Prat J. , Tabbutt M. , Busti V. , Becker M. R. , MacCrann N. , Diehl H. T. , Tucker D. L. , Bertin E. , Jeltema T. , Drlica-Wagner A. , Gruendl R. A. , Bechtol K. , Rosell A. Carnero , Abbott T. M. C. , Aguena M. , Annis J. , Bacon D. , Bhargava S. , Brooks D. , Burke D. L. , Kind M. Carrasco , Carretero J. , Castander F. J. , Conselice C. , Costanzi M. , da Costa L. N. , Pereira M. E. S. , De Vicente J. , DeRose J. , Desai S. , Eifler T. F. , Evrard A. E. , Ferrero I. , Fosalba P. , Frieman J. , García-Bellido J. , Gaztanaga E. , Gerdes D. W. , Gutierrez G. , Hinton S. R. , Hollowood D. L. , Honscheid K. , Huterer D. , James D. J. , Kent S. , Krause E. , Kuehn K. , Lahav O. , Lima M. , Lin H. , Maia M. A. G. , Marshall J. L. , Melchior P. , Menanteau F. , Miquel R. , Mohr J. J. , Morgan R. , Muir J. , Ogando R. L. C. , Palmese A. , Paz-Chinchón F. , Plazas A. A. , Rodriguez-Monroy M. , Romer A. K. , Roodman A. , Sanchez E. , Scarpine V. , Serrano S. , Smith M. , Soares-Santos M. , Suchyta E. , Swanson M. E. C. , Tarle G. , To C. , Troxel M. A. , Varga T. N. , Weller J. , Wilkinson R. D. ,   (DES Collaboration)
Published: January 2022

Abstract
We describe an updated calibration and diagnostic framework, Balrog, used to directly sample the selection and photometric biases of the Dark Energy Survey (DES) Year 3 (Y3) data set. We systematically inject onto the single-epoch images of a random 20% subset of the DES footprint an ensemble of nearly 30 million realistic galaxy models derived from DES Deep Field observations. These augmented images are analyzed in parallel with the original data to automatically inherit measurement systematics that are often too difficult to capture with generative models. The resulting object catalog is a Monte Carlo sampling of the DES transfer function and is used as a powerful diagnostic and calibration tool for a variety of DES Y3 science, particularly for the calibration of the photometric redshifts of distant “source” galaxies and magnification biases of nearer “lens” galaxies. The recovered Balrog injections are shown to closely match the photometric property distributions of the Y3 GOLD catalog, particularly in color, and capture the number density fluctuations from observing conditions of the real data within 1% for a typical galaxy sample. We find that Y3 colors are extremely well calibrated, typically within ∼1–8 mmag, but for a small subset of objects, we detect significant magnitude biases correlated with large overestimates of the injected object size due to proximity effects and blending. We discuss approaches to extend the current methodology to capture more aspects of the transfer function and reach full coverage of the survey footprint for future analyses.
TESS Eclipsing Binary Stars. I. Short-cadence Observations of 4584 Eclipsing Binaries in Sectors 1–26
Authors: Prša Andrej , Kochoska Angela , Conroy Kyle E. , Eisner Nora , Hey Daniel R. , IJspeert Luc , Kruse Ethan , Fleming Scott W. , Johnston Cole , Kristiansen Martti H. , LaCourse Daryll , Mortensen Danielle , Pepper Joshua , Stassun Keivan G. , Torres Guillermo , Abdul-Masih Michael , Chakraborty Joheen , Gagliano Robert , Guo Zhao , Hambleton Kelly , Hong Kyeongsoo , Jacobs Thomas , Jones David , Kostov Veselin , Lee Jae Woo , Omohundro Mark , Orosz Jerome A. , Page Emma J. , Powell Brian P. , Rappaport Saul , Reed Phill , Schnittman Jeremy , Schwengeler Hans Martin , Shporer Avi , Terentev Ivan A. , Vanderburg Andrew , Welsh William F. , Caldwell Douglas A. , Doty John P. , Jenkins Jon M. , Latham David W. , Ricker George R. , Seager Sara , Schlieder Joshua E. , Shiao Bernie , Vanderspek Roland , Winn Joshua N. 
Published: January 2022

Abstract
In this paper we present a catalog of 4584 eclipsing binaries observed during the first two years (26 sectors) of the TESS survey. We discuss selection criteria for eclipsing binary candidates, detection of hitherto unknown eclipsing systems, determination of the ephemerides, the validation and triage process, and the derivation of heuristic estimates for the ephemerides. Instead of keeping to the widely used discrete classes, we propose a binary star morphology classification based on a dimensionality reduction algorithm. Finally, we present statistical properties of the sample, we qualitatively estimate completeness, and we discuss the results. The work presented here is organized and performed within the TESS Eclipsing Binary Working Group, an open group of professional and citizen scientists; we conclude by describing ongoing work and future goals for the group. The catalog is available from http://tessEBs.villanova.edu and from MAST.
Ammonia Emission in Various Star-forming Environments: A Pilot Study of Planck Galactic Cold Clumps
Authors: Fehér O. , Tóth L. Viktor , Kraus Alex , Bőgner Rebeka , Kim Gwanjeong , Liu Tie , Tatematsu Ken’ichi , Tóth Victor , Eden David J. , Hirano Naomi , Juvela Mika , Kim Kee-Tae , Li Di , Liu Sheng-Yuan , Wu Yuefang ,   The TOP-SCOPE Collaboration
Published: January 2022

Abstract
The Planck Catalogue of Galactic Cold Clumps provides an all-sky sample of potential star-forming regions based on the submillimeter emission of their dust content. Around 1000 of these Planck objects were mapped with the James Clerk Maxwell telescope in the submillimeter range during the SCOPE survey, identifying prestellar and protostellar dense clumps inside them. We used the Effelsberg 100 m telescope to observe the emission lines of the NH3 inversion transitions toward a sample of 97 dense objects in varying environments in order to assess the physical parameters of their gas content. We derive their temperature, density, and velocity dispersion, correlating the resulting parameters with the environmental and evolutionary characteristics of the targets and with regard to their distance and physical size. We examine the dependence of physical parameters on distance and Galactic position and compare the gas-based and dust-continuum-based temperatures and densities. Together with the presence of maser emission and higher inversion transitions of ammonia, we may differentiate between certain groups of targets, e.g., filamentary, protostellar clumps, and high-latitude, core-sized, starless sources.
A New Discrete Implicit Monte Carlo Scheme for Simulating Radiative Transfer Problems
Authors: Steinberg Elad , Heizler Shay I. 
Published: January 2022

Abstract
We present a new algorithm for radiative transfer—based on a statistical Monte Carlo approach—that does not suffer from teleportation effects, on the one hand, and yields smooth results, on the other hand. Implicit Monte Carlo (IMC) techniques for modeling radiative transfer have existed from the 1970s. When they are used for optically thick problems, however, the basic algorithm suffers from “teleportation” errors, where the photons propagate faster than the exact physical behavior, due to the absorption-blackbody emission processes. One possible solution is to use semianalog Monte Carlo, in its new implicit form (ISMC), which uses two kinds of particles, photons and discrete material particles. This algorithm yields excellent teleportation-free results, but it also produces noisier solutions (relative to classic IMC), due to its discrete nature. Here, we derive a new Monte Carlo algorithm, Discrete Implicit Monte Carlo (DIMC), which also uses the idea of two kinds of discrete particles, and thus does not suffer from teleportation errors. DIMC implements the IMC discretization and creates new radiation photons for each time step, unlike ISMC. Using the continuous absorption technique, DIMC yields smooth results like classic IMC. One of the main elements of the algorithm is the avoidance of the explosion of the particle population, by using particle merging. We test the new algorithm on 1D and 2D cylindrical problems, and show that it yields smooth, teleportation-free results. We finish by demonstrating the power of the new algorithm on a classic radiative hydrodynamic problem—an opaque radiative shock wave. This demonstrates the power of the new algorithm for astrophysical scenarios.
What Seismic Minimum Reveals about Solar Magnetism below the Surface
Authors: Jain Kiran , Jain Niket , Tripathy Sushanta C. , Dikpati Mausumi 
Published: January 2022

Abstract
The Sun’s magnetic field varies on multiple timescales. Observations show that the minimum between cycles 24 and 25 was the second consecutive minimum that was deeper and wider than several earlier minima. Since the active regions observed at the Sun’s surface are manifestations of the magnetic field generated in the interior, it is crucial to investigate/understand the dynamics below the surface. In this context, we report by probing the solar interior with helioseismic techniques applied to long-term oscillations data from the Global Oscillation Network Group, that the seismic minima in deeper layers have been occurring about a year earlier than that at the surface for the last two consecutive solar cycles. Our findings also demonstrate a decrease in strong magnetic fields at the base of the convection zone, the primary driver of the surface magnetic activity. We conclude that the magnetic fields located in the core and near-surface shear layers, in addition to the tachocline fields, play an important role in modifying the oscillation frequencies. This further strengthens the existence of a relic magnetic field in the Sun’s core.
Parker Solar Probe Evidence for the Absence of Whistlers Close to the Sun to Scatter Strahl and to Regulate Heat Flux
Authors: Cattell C. , Breneman A. , Dombeck J. , Hanson E. , Johnson M. , Halekas J. , Bale S. D. , Dudok de Wit T. , Goetz K. , Goodrich K. , Malaspina D. , Pulupa M. , Case T. , Kasper J. C. , Larson D. , Stevens M. , Whittlesey P. 
Published: January 2022

Abstract
Using the Parker Solar Probe FIELDS bandpass-filter data and SWEAP electron data from Encounters 1 through 9, we show statistical properties of narrowband whistlers from ∼16 R
s to ∼130 R
s, and compare wave occurrence to electron properties including beta, temperature anisotropy, and heat flux. Whistlers are very rarely observed inside ∼28 R
s (∼0.13 au). Outside 28 R
s, they occur within a narrow range of parallel electron beta from ∼1 to 10, and with a beta-heat flux occurrence consistent with the whistler heat flux fan instability. Because electron distributions inside ∼30 R
s display signatures of the ambipolar electric field, the lack of whistlers suggests that the modification of the electron distribution function associated with the ambipolar electric field or changes in other plasma properties must result in lower instability limits for the other modes (including the observed solitary waves and ion acoustic waves) that are observed close to the Sun. The lack of narrowband whistler-mode waves close to the Sun and in regions of either low (<0.1) or high (>10) beta is also significant for the understanding and modeling of the evolution of flare-accelerated electrons and the regulation of heat flux in astrophysical settings including other stellar winds, the interstellar medium, accretion disks, and the intragalaxy cluster medium.
Three-Dimensional Anisotropy and Scaling Properties of Solar Wind Turbulence at Kinetic Scales in the Inner Heliosphere: Parker Solar Probe Observations
Authors: Zhang J. , Huang S. Y. , He J. S. , Wang T. Y. , Yuan Z. G. , Deng X. H. , Jiang K. , Wei Y. Y. , Xu S. B. , Xiong Q. Y. , Lin R. T. , Yu L. 
Published: January 2022

Abstract
We utilize the data from the Parker Solar Probe mission at its first perihelion to investigate the three-dimensional (3D) anisotropies and scalings of solar wind turbulence for the total, perpendicular, and parallel magnetic-field fluctuations at kinetic scales in the inner heliosphere. By calculating the five-point second-order structure functions, we find that the three characteristic lengths of turbulence eddies for the total and the perpendicular magnetic-field fluctuations in the local reference frame

(

L

ˆ

⊥

,

l

ˆ

⊥

,

l

ˆ

∣
∣

)

defined with respect to the local mean magnetic field
B

local feature as l
∣∣ > L
⊥ > l
⊥ in both the transition range and the ion-to-electron scales, but l
∣∣ > L
⊥ ≈ l
⊥ for the parallel magnetic-field fluctuations. For the total magnetic-field fluctuations, the wave-vector anisotropy scalings are characterized by

l

∣
∣

∝

l

⊥

0.78

and

L

⊥

∝

l

⊥

1.02

in the transition range, and they feature as

l

∣
∣

∝

l

⊥

0.44

and

L

⊥

∝

l

⊥

0.73

in the ion-to-electron scales. Still, we need more complete kinetic-scale turbulence models to explain all these observational results.
The Appearance of a “Fresh” Surface on 596 Scheila as a Consequence of the 2010 Impact Event
Authors: Hasegawa Sunao , Marsset Michaël , DeMeo Francesca E. , Bus Schelte J. , Ishiguro Masateru , Kuroda Daisuke , Binzel Richard P. , Hanuš Josef , Nakamura Akiko M. , Yang Bin , Vernazza Pierre 
Published: January 2022

Abstract
Dust emission was detected on main-belt asteroid 596 Scheila in 2010 December and was attributed to the collision of a few-tens-of-meters projectile on the surface of the asteroid. In such an impact, the ejected material from the collided body is expected to mainly come from its fresh, unweathered subsurface. Therefore, it is expected that the surface of 596 was partially or entirely refreshed during the 2010 impact. By combining spectra of 596 from the literature and our own observations, we show that the 2010 impact event resulted in a significant slope change in the near-infrared (0.8–2.5 μm) spectrum of the asteroid, from moderately red (T type) before the impact to red (D type) after the impact. This provides evidence that red carbonaceous asteroids become less red with time due to space weathering, in agreement with predictions derived from laboratory experiments on the primitive Tagish Lake meteorite, which is spectrally similar to 596. This discovery provides the very first telescopic confirmation of the expected weathering trend of asteroids spectrally analog to Tagish Lake and/or anhydrous chondritic porous interplanetary dust particles. Our results also suggest that the population of implanted objects from the outer solar system is much larger than previously estimated in the main belt, but many of these objects are hidden below their space-weathered surfaces.
Observational Signatures of Tearing Instability in the Current Sheet of a Solar Flare
Authors: Lu Lei , Feng Li , Warmuth Alexander , Veronig Astrid M. , Huang Jing , Liu Siming , Gan Weiqun , Ning Zongjun , Ying Beili , Gao Guannan 
Published: January 2022

Abstract
Magnetic reconnection is a fundamental physical process converting magnetic energy into not only plasma energy but also particle energy in various astrophysical phenomena. In this Letter, we show a unique data set of a solar flare where various plasmoids were formed by a continually stretched current sheet. Extreme ultraviolet images captured reconnection inflows, outflows, and particularly the recurring plasma blobs (plasmoids). X-ray images reveal nonthermal emission sources at the lower end of the current sheet, presumably as large plasmoids with a sufficiently amount of energetic electrons trapped in them. In the radio domain, an upward, slowly drifting pulsation structure, followed by a rare pair of oppositely drifting structures, was observed. These structures are supposed to map the evolution of the primary and the secondary plasmoids formed in the current sheet. Our results on plasmoids at different locations and scales shed important light on the dynamics, plasma heating, particle acceleration, and transport processes in the turbulent current sheet and provide observational evidence for the cascading magnetic reconnection process.