bluuebunny/crossref_metadata_2025 huggingface dataset:
Rheumatoid Arthritis Disability and Absence Trends in the United States
Authors: Brook Richard A , Kleinman Nathan L , Beren Ian A
Published: January 2022

Objectives: Employers increasingly focus on absence benefits and connections with employee health. United States absence benefits include Sick Leave (SL), Short- and Long-Term Disability (STD and LTD, respectively) for non-work-related injuries/illnesses, and Workers’ Compensation (WC) for work-related injuries/illnesses. This research explores all-cause absence (SL, STD, LTD, and WC) utilization and changes from baseline for eligible employees with rheumatoid arthritis to determine if the use a constant payment factor is appropriate for models. Study Design: Retrospective multi-year database analysis. Methods: The Workpartners database (1/1/2001-12/31/2019) was used to identify employees with rheumatoid arthritis with adjudicated medical claims. Annual prevalence, benefit utilization, mean days of leave, and median payments (as % of salary) were analyzed. Annual outcomes were calculated as a percent of baseline (2001). Results: Rheumatoid arthritis prevalence averaged 0.5% between 2001 and 2019. At baseline, the percent of eligible employees using STD = 15.5%, LTD = 0.7%, WC = 1.7%, SL = 61.7%. Mean absence days were 48.5, 367.5, 43.8 for STD, LTD, WC, respectively and median payments were 70.5%, 22.2%, 65.7% of salary for STD, LTD, WC, respectively. From 2002-2019: 11.7%-16.9% of eligible employees filed STD claims for 82.1%-995.9% of baseline days and 80.4%-125.9% median payments; 0.6%-2.9% of eligible employees filed LTD claims for 66.6%-114.7% of baseline days and 63.2%-254.8% median payments; 0.3%-1.6% of eligible employees filed WC claims for 44.0%-472.8% of baseline days and 70.4%-271.5% median payments. Median payments were highest in 2012, 2019, 2003 for STD, LTD, WC, respectively and the most absence days were used in 2017 for SL and LTD, 2008 for STD, and 2005 WC. Conclusion: Employees with rheumatoid arthritis used absence benefits at differing rates over time with varying leave-lengths and payments. Using a constant cost or salary replacement factor for absence costs over time and across benefits is not accurate.
Avifauna within the Main Campus of Imam Mohammad Ibn Saud Islamic University Riyadh, Saudi Arabia
Authors: Rudayni Hassan A
Published: January 2022

Avian diversity of two zones within the main campus of IMSIU University was studied during the period from July 2019 to June 2020. A total number of 1,653 individual birds was recorded across the main campus which falls under fifteen species belonging to thirteen families. Out of this number, 760 individual of them were recorded in Zone-A versus 893 individual in Zone-B. Species richness in Zone-A was 15 while species richness in Zone-B was 13. Census index of the Birds was recorded as follows: 4.6 Birds/ha and 7.9 Birds/ha in both Zones A and B, respectively. Bird species sighted was higher in Zone-B as compared with Zone-A, as indicated by Shannon-Wiener Diversity Index (H) which accounts for 1.83 in Zone-A and 1.65 in Zone-B. Pigeon (Columba livia), House Sparrow (Passer domesticus) and Laughing Dove (Spilopelia senegalensis) were among the most frequently sighted. From the current study, it is recommended that Zone-B be pedestrianized for the enrichment and protection of the avian species. Also, new policies should be put forward by the relevant authority within the main campus to maintain avian diversity, such as expanding afforestation and green landscapes, in addition to the establishment of artificial lakes and ponds.
Ecological Networks and Fluvial Corridors in Calabria (Southern Italy)
Authors: Cantasano Nicola
Published: January 2022

The anthropic pressure on natural systems is the main cause for the present process of biodiversity loss in terrestrial biosphere [1]. Really, the human disturbance on Earth affects the 74.1% of terrestrial and marine habitats, including 22.4% completely modified, 51.7% partially disturbed and just the 25.9% in natural and pristine conditions [2]. At the beginning of third millenium, in the middle of a post-industrial era, named “Anthropocene” [3], mankind is causing the greatest mass extinction of wildlife in terrestrial biosphere [4-6].
Modeling of Climatic Records for the Province of Villa Clara, Cuba
Authors: Rodriguez Ricardo Oses , Duarte Rigoberto Fimia
Published: January 2022

The objective of this work is to model the extreme temperature climatic records of Villa Clara Cuba and see if there is a trend in them, in addition the variable date on which they occurred was modeled, with the help of the Regressive Objective Regression (ROR). A database from 1966 to 2020 of the 4 weather stations with the account of the province of Villa Clara is used. The explained variance of the models is 100% for the maximum temperature and 99.8 for the minimum with errors of 0.58 and 1.4ºC. You can estimate the graphs for the maximum temperature as for the minimum with the predicted values ​​and the errors that the model commits. The trend for the date of the maximum trend is negative while for the minimum it is positive. The records depend on the temperature returned in 1 month (LAG1T) and the temperature returned in 12 months (LAG12T), both for the maximum TX and for the minimum TN, as well as the station value. The correlations between the actual and predicted value for the maximum and minimum temperature records and for the date models are high, greater than 90% and 99% variable.
„Mesterséges intelligencia a köz szolgálatában”
Authors: Hertelendi Lajos , Hornyik Zsuzsanna
Published: January 2022

The solutions inherent in artificial intelligence offer opportunities for many innovative developments in many areas of life, including public administration. The Deputy Secretariat of State for IT Development in the Ministry of the Interior realised significant improvements in the administration system meeting citizens in the past few years. We have come to the point where administration tries to “get known” the language of the citizens. The aim is to process the spoken text that can be heard by our ears, and its usability in official matters. And all we need is only a chat robot with artificial intelligence. We asked Károly Hajzer, deputy secretary of state for information technology, about tangible changes that have taken place and how many different areas have been affected by recent developments. The interview was conducted by Lajos Hertelendi, cooperative editor and Zsuzsanna Hornyik, deputy editor-in-chief.
Bűnügyi adatgyűjtés és adatfelhasználás a klinikai profilalkotás tükrében
Authors: Bellavics Zsóka Mária
Published: January 2022

The aim of the present study is to investigate the place of clinical and psychiatric expertise in the service of law enforcement, with special regard to the method of profiling. We introduce the nature of clinical expertise and briefly describe the professions that perform diagnostic activities in the clinical practice. We present the importance of psychiatric knowledge based on relevant international and domestic findings related to crime. We examine professional experiences that raise the need for a psychiatric specialization focusing on the mental conditions that arise in connection with crime. In this context, we do not give examples of mental disorders only, relatively neglected in civilian care, but may have importance in cases of violent offences, and also demonstrate the complex nature of the psychiatric disorders associated with crime, which requires special police expertise besides clinical. Finally, we recommend the first steps needed to establish the specialization of criminal psychiatry.
AN ONLINE REVIEWS INFORMATION FUSION METHOD AND ITS APPLICATION TO PUBLIC PROPERTY SERVICE QUALITY EVALUATION
Authors: Lin Shanshan , Zuo Wenjin , Lin Hualin , Hu Qiang
Published: January 2022

With the rapid development of computer networking technology, people pay more and more attention to the role of online reviews in management decision making. The existing methods of online reviews fusion are limited to rational decision-making behavior, which does not accord with the characteristics of evaluators’ behavior characteristics in the real environment. In order to solve the online reviews fusion problem based on bounded rational behavior which is closer to the reality of property service quality evaluation, the multi-index and multi-scale (MIMS) method is extended into the generalized form, the online reviews are quantified by using the adverb structure scaling method, and an online reviews fusion method based on the improved TODIM (an acronym in Portuguese of interactive and multi-criteria decision making) model is proposed. The feasibility and effectiveness of the proposed method are verified by an example analysis of property service quality evaluation. The research results are as follows: the adverb structure scaling method is suitable for a large number of online reviews processing, the proposed method improves the efficiency of online reviews information fusion, and it is feasible and effective to evaluate property service quality based on the bounded rationality of evaluator’s behavior.
BARRIERS TO THE ADOPTION OF NEW SAFETY TECHNOLOGIES IN CONSTRUCTION: A DEVELOPING COUNTRY CONTEXT
Authors: Yap Jeffrey Boon Hui , Lam Canwin Guan Ying , Skitmore Martin , Talebian Nima
Published: January 2022

The adoption rate of new technologies is still relatively low in the construction industry, particularly for mitigating occupational safety and health (OSH) risks, which is traditionally a largely labor-intensive activity in developing countries, occupying ill-afforded non-productive management resources. However, understanding why this is the case is a relatively unresearched area in developing countries such as Malaysia. In aiming to help redress this situation, this study explored the major barriers involved, firstly by a detailed literature review to identify the main barriers hampering the adoption of new technologies for safety science and management in construction. Then, a questionnaire survey of Malaysian construction practitioners was used to prioritize these barriers. A factor analysis further identified six major dimensions underlying the barriers, relating to the lack of OSH regulations and legislation, technological limitations, lack of genuine organizational commitment, prohibitive costs, poor safety culture within the construction industry, and privacy and data security concerns. Taken together, the findings provide a valuable reference to assist industry practitioners and researchers regarding the critical barriers to the adoption of new technologies for construction safety management in Malaysia and other similar developing countries, and bridge the identified knowledge gap concerning the dimensionality of the barriers.
RENT-SEEKING DECISIONS OF THE MAIN PARTICIPANTS IN CONSTRUCTION PROJECTS BASED ON EVOLUTIONARY-GAME AND SYSTEM DYNAMICS
Authors: Zuo Weiwei , Wang Qiankun , Li Peng
Published: January 2022

The performance of a construction project can be severely harmed by its participants’ rent-seeking. In order to prevent such attempt, this research integrates the evolutionary game theory with system dynamics method to simulate the impact of the change of some factors that may cause/reduce rent-seeking. Based on the analysis of the behavioral characteristics and interactive relationships of the main participants (the owner, supervisor, and contractor), an evolutionary game model is constructed and simulated with the method of system dynamics based on the replication dynamic equation of the mixed strategy solution of the three-party static game model. By assigning the parameters of project scale, supervision likelihood, supervision success rate, supervision cost, and penalty intensity, the interaction mechanism of the participants on each factor is revealed through a case-based simulation. The results show that the impacts of these factors on participants’ rent-seeking decisions are significantly different. Furthermore, some management suggestions are provided to prevent rent-seeking for project owner according to the research conclusions. This research can help the project owners take proper measures to prevent rent-seeking of the supervisors and the contractors to improve the performances of the projects.
Revisiting KELT-19Ab, WASP-156b, and WASP-121b in the TESS Era
Authors: Yang Fan , Chary Ranga-Ram , Liu Ji-Feng
Published: January 2022

We present a re-analysis of transit depths of KELT-19Ab, WASP-156b, and WASP-121b, including data from the Transiting Exoplanet Survey Satellite (TESS). The large ∼21″ TESS pixels and point-spread function result in significant contamination of the stellar flux by nearby objects. We use Gaia data to fit for and remove this contribution, providing general-purpose software for this correction. We find all three sources have a larger inclination, compared to earlier work. For WASP-121b, we find significantly smaller values (13.°5) of the inclination when using the 30 minute cadence data compared to the 2 minute cadence data. Using simulations, we demonstrate that the radius ratio of exoplanet to star (Rp/R*) is biased small relative to data taken with a larger sampling interval although oversampling corrections mitigate the bias. This is particularly important for deriving subpercent transit differences between bands. We find the radius ratio of exoplanet to star (Rp/R*) in the TESS band is 7.5σsmaller than previous work for KELT-19Ab, but consistent to within ∼2σfor WASP-156b and WASP-121b. The difference could be due to specific choices in the analysis, not necessarily due to the presence of atmospheric features. The result for KELT-19Ab possibly favors a haze-dominated atmosphere. We do not find evidence for the ∼0.95μm water feature contaminating transit depths in the TESS band for these stars but show that with photometric precision of 500 ppm and with a sampling of about 200 observations across the entire transit, this feature could be detectable in a more narrowz-band.
Infrared Absolute Calibration. I. Comparison of Sirius with Fainter Calibration Stars
Authors: Rieke G. H. , Su Kate , Sloan G. C. , Schlawin E.
Published: January 2022

A challenge in absolute calibration is to relate very bright stars with physical flux measurements to faint ones within range of modern instruments, e.g., those on large ground-based telescopes or the James Webb Space Telescope (JWST). We propose Sirius as the fiducial color standard. It is an A0V star that is slowly rotating and does not have infrared excesses due to either hot dust or a planetary debris disk; it also has a number of accurate (∼1%–2%) absolute flux measurements. We accurately transfer the near-infrared flux from Sirius to BD +60 1753, an unobscured early A-type star (A1V, V ≈ 9.6, E(B – V) ≈ 0.009) that is faint enough to serve as a primary absolute flux calibrator for JWST. Its near-infrared spectral energy distribution and that of Sirius should be virtually identical. We have determined its output relative to that of Sirius in a number of different ways, all of which give consistent results within ∼1%. We also transfer the calibration to GSPC P330-E, a well-calibrated close solar analog (G2V). We have emphasized the 2MASS K

S
band, since it represents a large number and long history of measurements, but the theoretical spectra (i.e., from CALSPEC) of these stars can be used to extend this result throughout the near- and mid-infrared.
SDSS-IV MaStar: Data-driven Parameter Derivation for the MaStar Stellar Library
Authors: Imig Julie , Holtzman Jon A. , Yan Renbin , Lazarz Daniel , Chen Yanping , Hill Lewis , Thomas Daniel , Maraston Claudia , Prescott Moire K. M. , Stringfellow Guy S. , Bizyaev Dmitry , Beaton Rachael L. , Drory Niv
Published: January 2022

The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) Stellar Library (MaStar) is a large collection of high-quality empirical stellar spectra designed to cover all spectral types and ideal for use in the stellar population analysis of galaxies observed in the MaNGA survey. The library contains 59,266 spectra of 24,130 unique stars with spectral resolution R ∼ 1800 and covering a wavelength range of 3622–10,354 Å. In this work, we derive five physical parameters for each spectrum in the library: effective temperature (T
eff), surface gravity (

log
g

), metallicity ([Fe/H]), microturbulent velocity (

log
(

v

micro

)

), and alpha-element abundance ([α/Fe]). These parameters are derived with a flexible data-driven algorithm that uses a neural network model. We train a neural network using the subset of 1675 MaStar targets that have also been observed in the Apache Point Observatory Galactic Evolution Experiment (APOGEE), adopting the independently-derived APOGEE Stellar Parameter and Chemical Abundance Pipeline parameters for this reference set. For the regions of parameter space not well represented by the APOGEE training set (7000 ≤ T ≤ 30,000 K), we supplement with theoretical model spectra. We present our derived parameters along with an analysis of the uncertainties and comparisons to other analyses from the literature.
Parallax of Star-forming Region G027.22+0.14
Authors: Bian S. B. , Xu Y. , Li J. J. , Wu Y. W. , Zhang B. , Chen X. , Li Y. J. , Lin Z. H. , Hao C. J. , Liu D. J.
Published: January 2022

Using the Very Long Baseline Array, we measured the trigonometric parallax and proper motions toward a 6.7 GHz methanol maser in the distant high-mass star-forming region G027.22+0.14. The distance of this source is determined to be

6.3

−
0.5

+
0.6

kpc. Combining its Galactic coordinates, radial velocity, and proper motion, we assign G027.22+0.14 to the far portion of the Norma arm. The low peculiar motion and lower luminosity of G027.22+0.14 support the conjecture by Immer et al. that low-luminosity sources tend to have low peculiar motions.
A Semianalytic Afterglow with Thermal Electrons and Synchrotron Self-Compton Emission
Authors: Warren Donald C. , Dainotti Maria , Barkov Maxim V. , Ahlgren Björn , Ito Hirotaka , Nagataki Shigehiro
Published: January 2022

We extend previous work on gamma-ray burst afterglows involving hot thermal electrons at the base of a shock-accelerated tail. Using a physically motivated electron distribution based on first-principles simulations, we compute the broadband emission from radio to TeV gamma rays. For the first time, we present the effects of a thermal distribution of electrons on synchrotron self-Compton emission. The presence of thermal electrons causes temporal and spectral structure across the entire observable afterglow, which is substantively different from models that assume a pure power-law distribution for the electrons. We show that early-time TeV emission is enhanced by more than an order of magnitude for our fiducial parameters, with a time-varying spectral index that does not occur for a pure power law of electrons. We further show that the X-ray closure relations take a very different, also time-dependent, form when thermal electrons are present; the shape traced out by the X-ray afterglows is a qualitative match to observations of the traditional decay phase.
Supersonic Expansion of the Bipolar H ii Region Sh2-106: A 3500 Year Old Explosion?
Authors: Bally John , Chia Zen , Ginsburg Adam , Reipurth Bo , Tanaka Kei E. I , Zinnecker Hans , Faulhaber John
Published: January 2022

Multi-epoch narrowband Hubble Space Telescope images of the bipolar H ii region Sh2-106 reveal highly supersonic nebular proper motions that increase with projected distance from the massive young stellar object S106 IR, reaching over ∼30 mas yr−1 (∼150 km s−1 at D = 1.09 kpc) at a projected separation of ∼1.′4 (0.44 pc) from S106 IR. We propose that S106 IR experienced a ∼1047 erg explosion ∼3500 yr ago. The explosion may be the result of a major accretion burst or a recent encounter with another star, or a consequence of the interaction of a companion with the bloated photosphere of S106 IR as it grew from ∼10 through ∼15 M
⊙ at a high accretion rate. Near-IR images reveal fingers of H2 emission pointing away from S106 IR and an asymmetric photon-dominated region surrounding the ionized nebula. Radio continuum and Brγ emission reveal a C-shaped bend in the plasma, indicating either the motion of S106 IR toward the east, or the deflection of plasma toward the west by the surrounding cloud. The H ii region bends around a ∼1′ diameter dark bay west of S106 IR that may be shielded from direct illumination by a dense molecular clump. Herbig–Haro and Molecular Hydrogen Objects tracing outflows powered by stars in the Sh2-106 protocluster such as the Class 0 source S106 FIR are discussed.
Variable Ion Compositions of Solar Energetic Particle Events in the Inner Heliosphere: A Field Line Braiding Model with Compound Injections
Authors: Guo Fan , Zhao Lulu , Cohen Christina M. S. , Giacalone Joe , Leske R. A. , Wiedenbeck M. E. , Kahler S. W. , Li Xiaocan , Zhang Qile , Ho George C. , Desai Mihir I.
Published: January 2022

We propose a model for interpreting highly variable ion composition ratios in solar energetic particle (SEP) events recently observed by the Parker Solar Probe (PSP) at 0.3–0.45 au. We use numerical simulations to calculate SEP propagation in a turbulent interplanetary magnetic field with a Kolmogorov power spectrum from large scales down to the gyration scale of energetic particles. We show that when the source regions of different species are offset by a distance comparable to the size of the source regions, the observed energetic particle composition He/H can be strongly variable over more than two orders of magnitude, even if the source ratio is at the nominal value. Assuming a 3He/4He source ratio of 10% in impulsive 3He-rich events and the same spatial offset of the source regions, the 3He/4He ratio at observation sites also vary considerably. The variability of the ion composition ratios depends on the radial distance, which can be tested by observations made at different radial locations. We discuss the implications of these results on the variability of ion composition of impulsive events and on further PSP and Solar Orbiter observations close to the Sun.
SN 2015bq: A Luminous Type Ia Supernova with Early Flux Excess
Authors: Li Liping , Zhang Jujia , Dai Benzhong , Li Wenxiong , Wang Xiaofeng , Zhai Qian , Bai Jinming
Published: January 2022

We present optical and ultraviolet (UV) observations of a luminous type Ia supernova (SN Ia) SN 2015bq characterized by early flux excess. This SN reaches a B-band absolute magnitude at M

B
= −19.68 ± 0.41 mag and a peak bolometric luminosity at L = (1.75 ± 0.37) × 1043 erg s−1, with a relatively small post-maximum decline rate [Δm
15(B) = 0.82 ± 0.05 mag]. The flux excess observed in the light curves of SN 2015bq a few days after the explosion, especially seen in the UV bands, might be due to the radioactive decay of 56Ni mixed into the surface. The radiation from the decay of the surface 56Ni heats the outer layer of this SN. It produces blue U − B color followed by monotonically reddening in the early phase, dominated iron-group lines, and weak intermediate-mass element absorption features in the early spectra. The scenario of enhanced 56Ni in the surface is consistent with a large amount of 56Ni (

M

56

Ni

=
0.97
±
0.20

M
☉) synthesized during the explosion. The properties of SN 2015bq are found to locate between SN 1991T and SN 1999aa, suggesting the latter two subclasses of SNe Ia may have a common origin.
Simulation of Plasma Emission in Magnetized Plasmas
Authors: Lee Sang-Yun , Yoon Peter H. , Lee Ensang , Tu Weichao
Published: January 2022

The recent Parker Solar Probe observations of type III radio bursts show that the effects of the finite background magnetic field can be an important factor in the interpretation of data. In the present paper, the effects of the background magnetic field on the plasma-emission process, which is believed to be the main emission mechanism for solar coronal and interplanetary type III radio bursts, are investigated by means of the particle-in-cell simulation method. The effects of the ambient magnetic field are systematically surveyed by varying the ratio of plasma frequency to electron gyrofrequency. The present study shows that for a sufficiently strong ambient magnetic field, the wave–particle interaction processes lead to a highly field-aligned longitudinal mode excitation and anisotropic electron velocity distribution function, accompanied by a significantly enhanced plasma emission at the second-harmonic plasma frequency. For such a case, the polarization of the harmonic emission is almost entirely in the sense of extraordinary mode. On the other hand, for moderate strengths of the ambient magnetic field, the interpretation of the simulation result is less clear. The underlying nonlinear-mode coupling processes indicate that to properly understand and interpret the simulation results requires sophisticated analyses involving interactions among magnetized plasma normal modes, including the two transverse modes of the magneto-active plasma, namely, the extraordinary and ordinary modes, as well as electron-cyclotron-whistler, plasma oscillation, and upper-hybrid modes. At present, a nonlinear theory suitable for quantitatively analyzing such complex-mode coupling processes in magnetized plasmas is incomplete, which calls for further theoretical research, but the present simulation results could provide a guide for future theoretical efforts.
Discovery of a Double Radio Relic in ZwCl1447.2+2619: A Rare Testbed for Shock-acceleration Models with a Peculiar Surface-brightness Ratio
Authors: Lee Wonki , James Jee M. , Finner Kyle , HyeongHan Kim , Kale Ruta , Yoon Hyein , Forman William , Kraft Ralph , Jones Christine , Chung Aeree
Published: January 2022

We report a discovery of a double radio relic in the cluster merger ZwCl1447.2+2619 (z = 0.376) with uGMRT observations at 420 MHz and 700 MHz. The linear sizes of the northern and southern relics are ∼0.3 Mpc and ∼1.2 Mpc, respectively, which is consistent with the theoretical expectation that a larger relic is produced in the less massive subcluster side. However, ZwCl1447.2+2619 is unlike other known double radio relic systems, where the larger relics are much more luminous by several factors. In this merger, the higher surface brightness of the smaller northern relic makes its total radio luminosity comparable to that of the much larger southern relic. The surface brightness ratio ∼0.1 between the two radio relics differs significantly from the relation observed in other double radio relic systems. From our radio spectral analysis, we find that both relics signify similar weak shocks with Mach numbers of 2.9 ± 0.8 and 2.0 ± 0.7 for the northern and southern relics, respectively. Moreover, the northern relic is connected to a discrete radio source with an optical counterpart, which indicates the possible presence of cosmic-ray injection and reacceleration. Therefore, we propose that this atypical surface brightness ratio can be explained with the particle acceleration efficiency precipitously dropping in the weak shock regime and/or with reacceleration of fossil cosmic rays. Our multi-wavelength analysis and numerical simulation suggest that ZwCl1447.2+2619 is a postmerger, which has experienced a near head-on collision ∼0.7 Gyr ago.
Validation of the HERA Phase I Epoch of Reionization 21 cm Power Spectrum Software Pipeline
Authors: Aguirre James E. , Murray Steven G. , Pascua Robert , Martinot Zachary E. , Burba Jacob , Dillon Joshua S. , Jacobs Daniel C. , Kern Nicholas S. , Kittiwisit Piyanat , Kolopanis Matthew , Lanman Adam , Liu Adrian , Whitler Lily , Abdurashidova Zara , Alexander Paul , Ali Zaki S. , Balfour Yanga , Beardsley Adam P. , Bernardi Gianni , Billings Tashalee S. , Bowman Judd D. , Bradley Richard F. , Bull Philip , Carey Steve , Carilli Chris L. , Cheng Carina , DeBoer David R. , Dexter Matt , de Lera Acedo Eloy , Ely John , Ewall-Wice Aaron , Fagnoni Nicolas , Fritz Randall , Furlanetto Steven R. , Gale-Sides Kingsley , Glendenning Brian , Gorthi Deepthi , Greig Bradley , Grobbelaar Jasper , Halday Ziyaad , Hazelton Bryna J. , Hewitt Jacqueline N. , Hickish Jack , Julius Austin , Kerrigan Joshua , Kohn Saul A. , La Plante Paul , Lekalake Telalo , Lewis David , MacMahon David , Malan Lourence , Malgas Cresshim , Maree Matthys , Matsetela Eunice , Mesinger Andrei , Molewa Mathakane , Morales Miguel F. , Mosiane Tshegofalang , Neben Abraham R. , Nikolic Bojan , Parsons Aaron R. , Patra Nipanjana , Pieterse Samantha , Pober Jonathan C. , Razavi-Ghods Nima , Ringuette Jon , Robnett James , Rosie Kathryn , Santos Mario G. , Sims Peter , Singh Saurabh , Smith Craig , Syce Angelo , Thyagarajan Nithyanandan , Williams Peter K. G. , Zheng Haoxuan ,   HERA Collaboration
Published: January 2022

We describe the validation of the HERA Phase I software pipeline by a series of modular tests, building up to an end-to-end simulation. The philosophy of this approach is to validate the software and algorithms used in the Phase I upper-limit analysis on wholly synthetic data satisfying the assumptions of that analysis, not addressing whether the actual data meet these assumptions. We discuss the organization of this validation approach, the specific modular tests performed, and the construction of the end-to-end simulations. We explicitly discuss the limitations in scope of the current simulation effort. With mock visibility data generated from a known analytic power spectrum and a wide range of realistic instrumental effects and foregrounds, we demonstrate that the current pipeline produces power spectrum estimates that are consistent with known analytic inputs to within thermal noise levels (at the 2σ level) for k > 0.2h Mpc−1 for both bands and fields considered. Our input spectrum is intentionally amplified to enable a strong “detection” at k ∼ 0.2 h Mpc−1—at the level of ∼25σ—with foregrounds dominating on larger scales and thermal noise dominating at smaller scales. Our pipeline is able to detect this amplified input signal after suppressing foregrounds with a dynamic range (foreground to noise ratio) of ≳107. Our validation test suite uncovered several sources of scale-independent signal loss throughout the pipeline, whose amplitude is well-characterized and accounted for in the final estimates. We conclude with a discussion of the steps required for the next round of data analysis.
A Quasar-based Supermassive Black Hole Binary Population Model: Implications for the Gravitational Wave Background
Authors: Casey-Clyde J. Andrew , Mingarelli Chiara M. F. , Greene Jenny E. , Pardo Kris , Nañez Morgan , Goulding Andy D.
Published: January 2022

The nanohertz gravitational wave background (GWB) is believed to be dominated by GW emission from supermassive black hole binaries (SMBHBs). Observations of several dual-active galactic nuclei (AGN) strongly suggest a link between AGN and SMBHBs, given that these dual-AGN systems will eventually form bound binary pairs. Here we develop an exploratory SMBHB population model based on empirically constrained quasar populations, allowing us to decompose the GWB amplitude into an underlying distribution of SMBH masses, SMBHB number density, and volume enclosing the GWB. Our approach also allows us to self-consistently predict the number of local SMBHB systems from the GWB amplitude. Interestingly, we find the local number density of SMBHBs implied by the common-process signal in the NANOGrav 12.5-yr data set to be roughly five times larger than previously predicted by other models. We also find that at most ∼25% of SMBHBs can be associated with quasars. Furthermore, our quasar-based approach predicts ≳95% of the GWB signal comes from z ≲ 2.5, and that SMBHBs contributing to the GWB have masses ≳108
M
⊙. We also explore how different empirical galaxy–black hole scaling relations affect the local number density of GW sources, and find that relations predicting more massive black holes decrease the local number density of SMBHBs. Overall, our results point to the important role that a measurement of the GWB will play in directly constraining the cosmic population of SMBHBs, as well as their connections to quasars and galaxy mergers.
Late-time Evolution and Modeling of the Off-axis Gamma-Ray Burst Candidate FIRST J141918.9+394036
Authors: Mooley K. P. , Margalit B. , Law C. J. , Perley D. A. , Deller A. T. , Lazio T. J. W. , Bietenholz M. F. , Shimwell T. , Intema H. T. , Gaensler B. M. , Metzger B. D. , Dong D. Z. , Hallinan G. , Ofek E. O. , Sironi L.
Published: January 2022

We present new radio and optical data, including very-long-baseline interferometry, as well as archival data analysis, for the luminous, decades-long radio transient FIRST J141918.9+394036. The radio data reveal a synchrotron self-absorption peak around 0.3 GHz and a radius of around 1.3 mas (0.5 pc) 26 yr post-discovery, indicating a blastwave energy ∼5 × 1050 erg. The optical spectrum shows a broad [O iii]λ4959,5007 emission line that may indicate collisional excitation in the host galaxy, but its association with the transient cannot be ruled out. The properties of the host galaxy are suggestive of a massive stellar progenitor that formed at low metallicity. Based on the radio light curve, blastwave velocity, energetics, nature of the host galaxy and transient rates, we find that the properties of J1419+3940 are most consistent with long gamma-ray burst (LGRB) afterglows. Other classes of (optically discovered) stellar explosions as well as neutron star mergers are disfavored, and invoking any exotic scenario may not be necessary. It is therefore likely that J1419+3940 is an off-axis LGRB afterglow (as suggested by Law et al. and Marcote et al.), and under this premise the inverse beaming fraction is found to be

f

b

−
1

≃

280

−
200

+
700

, corresponding to an average jet half-opening angle

<

θ

j

>
≃

5

−
2

+
4

degrees (68% confidence), consistent with previous estimates. From the volumetric rate we predict that surveys with the Very Large Array, Australian Square Kilometre Array Pathfinder, and MeerKAT will find a handful of J1419+3940-like events over the coming years.
Detection of a 100,000 M
⊙ black hole in M31's Most Massive Globular Cluster: A Tidally Stripped Nucleus
Authors: Pechetti Renuka , Seth Anil , Kamann Sebastian , Caldwell Nelson , Strader Jay , den Brok Mark , Luetzgendorf Nora , Neumayer Nadine , Voggel Karina
Published: January 2022

We investigate the presence of a central black hole (BH) in B023-G078, M31's most massive globular cluster. We present high-resolution, adaptive-optics assisted, integral-field spectroscopic kinematics from Gemini/NIFS that show a strong rotation (∼20 km s−1) and a velocity dispersion rise toward the center (37 km s−1). We combine the kinematic data with a mass model based on a two-component fit to HST ACS/HRC data of the cluster to estimate the mass of a putative BH. Our dynamical modeling suggests a >3σ detection of a BH component of

9.1

−
2.8

+
2.6

×

10

4

M

⊙

(1σ uncertainties). The inferred stellar mass of the cluster is

6.22

−
0.05

+
0.03

×

10

6

M

⊙

, consistent with previous estimates, thus the BH makes up 1.5% of its mass. We examine whether the observed kinematics are caused by a collection of stellar mass BHs by modeling an extended dark mass as a Plummer profile. The upper limit on the size scale of the extended mass is 0.56 pc (95% confidence), which does not rule out an extended mass. There is compelling evidence that B023-G078 is the tidally stripped nucleus of a galaxy with a stellar mass >109
M
⊙, including its high-mass, two-component luminosity profile, color, metallicity gradient, and spread in metallicity. Given the emerging evidence that the central BH occupation fraction of >109
M
⊙ galaxies is high, the most plausible interpretation of the kinematic data is that B023-G078 hosts a central BH. This makes it the strongest BH detection in a lower-mass (<107
M
⊙) stripped nucleus, and one of the few dynamically detected intermediate-mass BHs.
V606 Cen: A Newly Formed Massive Contact Binary in a Hierarchical Triple System
Authors: Li F.-X. , Liao W.-P. , Qian S.-B. , Fernández Lajús E. , Zhang J. , Zhao E.-G.
Published: January 2022

V606 Centauri (V606 Cen) is an early B-type close binary with an orbital period of 1.4950935 days, and its complete light curves are very difficult to observe on the ground. By analyzing the continuous light curve obtained by TESS, we found that it is a marginal contact binary with a very low fill-out factor of about 2%. The O − C diagram of V606 Cen is constructed for the first time based on 118.8 yr of eclipse times. The O − C diagram has been found to show a downward parabolic change together with a cyclic oscillation with a semiamplitude of 0.0545 days and a period of 88.3 yr. The downward parabolic variation reveals a linear period decrease at a rate of dP/dt = −2.08 × 10−7 days yr−1 that can be explained by the mass transfer from the more massive component to the less massive one. Both the marginal contact configuration and the continuous period decrease suggest that V606 Cen is a newly formed contact binary via Case A mass transfer. The cyclic change in the O − C diagram can be explained by the light-travel time effect via the presence of a third body. The lowest mass of the tertiary companion is determined to be M
3 = 4.51 (±0.43) M
⊙ and the tertiary is orbiting around the central eclipsing binary in a nearly circular orbit (e = 0.33). All of the results indicate that V606 Cen is a newly formed massive contact binary in a hierarchical triple system.
The Physical Parameters of Four WC-type Wolf–Rayet Stars in the Large Magellanic Cloud: Evidence of Evolution*
Authors: Aadland Erin , Massey Philip , Hillier D. John , Morrell Nidia
Published: January 2022

We present a spectral analysis of four Large Magellanic Cloud (LMC) WC-type Wolf–Rayet (WR) stars (BAT99-8, BAT99-9, BAT99-11, and BAT99-52) to shed light on two evolutionary questions surrounding massive stars. The first is: are WO-type WR stars more oxygen enriched than WC-type stars, indicating further chemical evolution, or are the strong high-excitation oxygen lines in WO-type stars an indication of higher temperatures. This study will act as a baseline for answering the question of where WO-type stars fall in WR evolution. Each star’s spectrum, extending from 1100 to 25000 Å, was modeled using cmfgen to determine the star’s physical properties such as luminosity, mass-loss rate, and chemical abundances. The oxygen abundance is a key evolutionary diagnostic, and with higher resolution data and an improved stellar atmosphere code, we found the oxygen abundance to be up to a factor of 5 lower than that of previous studies. The second evolutionary question revolves around the formation of WR stars: do they evolve by themselves or is a close companion star necessary for their formation? Using our derived physical parameters, we compared our results to the Geneva single-star evolutionary models and the Binary Population and Spectral Synthesis (BPASS) binary evolutionary models. We found that both the Geneva solar-metallicity models and BPASS LMC-metallicity models are in agreement with the four WC-type stars, while the Geneva LMC-metallicity models are not. Therefore, these four WC4 stars could have been formed either via binary or single-star evolution.
Ultra-high-energy Gamma-Ray Radiation from the Crab Pulsar Wind Nebula
Authors: Nie Lin , Liu Yang , Jiang Zejun , Geng Xiongfei
Published: January 2022

It has been long debated whether the high-energy gamma-ray radiation from the Crab Nebula stems from leptonic or hadronic processes. In this work, we investigate the multiband nonthermal radiation from the Crab pulsar wind nebula with the leptonic and leptonic–hadronic hybrid models, respectively. Then we use the Markov Chain Monte Carlo sampling technology and method of sampling trace to study the stability and reasonability of the model parameters according to the recently observed results and obtain the best-fitting values of parameters. Finally, we calculate different radiative components generated by the electrons and protons in the Crab Nebula. The modeling results indicate that the pure leptonic origin model with the one-zone only can partly agree with some segments of the data from various experiments (including the PeV gamma-ray emission reported by the LHAASO and the other radiation ranging from the radio to very-high-energy gamma-ray wave band), and the contribution of hadronic interaction is hardly constrained. However, we find that the hadronic process may also contribute, especially in the energy range exceeding the PeV. In addition, it can be inferred that the higher energy signals from the Crab Nebula could be observed in the future.
The Distance and Dynamical History of the Virgo Cluster Ultradiffuse Galaxy VCC 615
Authors: Mihos J. Christopher , Durrell Patrick R. , Toloba Elisa , Côté Patrick , Ferrarese Laura , Guhathakurta Puragra , Lim Sungsoon , Peng Eric W. , Sales Laura V.
Published: January 2022

We use deep Hubble Space Telescope imaging to derive a distance to the Virgo Cluster ultradiffuse galaxy (UDG) VCC 615 using the tip of the red giant branch (TRGB) distance estimator. We detect 5023 stars within the galaxy, down to a 50% completeness limit of F814W ≈ 28.0, using counts in the surrounding field to correct for contamination due to background sources and Virgo intracluster stars. We derive an extinction-corrected F814W tip magnitude of

m

tip
,
0

=

27.19

−
0.05

+
0.07

, yielding a distance of

d
=

17.7

−
0.4

+
0.6

Mpc. This places VCC 615 on the far side of the Virgo Cluster (d
Virgo = 16.5 Mpc), at a Virgocentric distance of 1.3 Mpc and near the virial radius of the main body of Virgo. Coupling this distance with the galaxy’s observed radial velocity, we find that VCC 615 is on an outbound trajectory, having survived a recent passage through the inner parts of the cluster. Indeed, our orbit modeling gives a 50% chance the galaxy passed inside the Virgo core (r < 620 kpc) within the past gigayear, although very close passages directly through the cluster center (r < 200 kpc) are unlikely. Given VCC 615's undisturbed morphology, we argue that the galaxy has experienced no recent and sudden transformation into a UDG due to the cluster potential, but rather is a long-lived UDG whose relatively wide orbit and large dynamical mass protect it from stripping and destruction by the Virgo cluster tides. Finally, we also describe the serendipitous discovery of a nearby Virgo dwarf galaxy projected 90″ (7.2 kpc) away from VCC 615.
Isotopic Compositions of Ruthenium Predicted from the NuGrid Project
Authors: Kim Seonho , Hyun Sung Kwang , Kwak Kyujin
Published: January 2022

The isotopic compositions of ruthenium (Ru) are measured from presolar silicon carbide (SiC) grains. In a popular scenario, the presolar SiC grains formed in the outskirt of an asymptotic giant branch (AGB) star, left the star as a stellar wind, and joined the presolar molecular cloud from which the solar system formed. The Ru isotopes formed inside the star, moved to the stellar surface during the AGB phase, and were locked into the SiC grains. Following this scenario, we analyze the Nucleosynthesis Grid (NuGrid) data, which provide the abundances of the Ru isotopes in the stellar wind for a set of stars in a wide range of initial masses and metallicities. We apply the C > O (carbon abundance larger than the oxygen abundance) condition, which is commonly adopted for the condition of the SiC formation in the stellar wind. The NuGrid data confirm that SiC grains do not form in the winds of massive stars. The isotopic compositions of Ru in the winds of low-mass stars can explain the measurements. We find that lower-mass stars (1.65 M
☉ and 2 M
☉) with low metallicity (Z = 0.0001) can explain most of the measured isotopic compositions of Ru. We confirm that the abundance of 99 Ru inside the presolar grain includes the contribution from the in situ decay of 99 Tc. We also verify our conclusion by comparing the isotopic compositions of Ru integrated over all the pulses with those calculated at individual pulses.
Ion Current Screening Modeling of the Ion–Weibel Instability
Authors: Jiao J. L.
Published: January 2022

Ion–Weibel instability (IWI) is an important mechanism of generating a magnetic field in supernova remnants; it plays a key role in the generation of high-energy cosmic rays. Computational efficiency has been a bottleneck in numerical exploration of the large-scale evolution of IWI. Here I report a new hybrid particle-in-cell (PIC) method that can quickly simulate IWI. The method is based on a new model that describes the relation of the ion current and its magnetic field under the electron screening. The new method’s computational efficiency is nearly two orders of magnitude higher than that of the PIC method. This method is suitable for the full-scale simulation of the IWI in laser-plasma experiments and supernova remnants.
Relating the Solar Wind Turbulence Spectral Break at the Dissipation Range with an Upstream Spectral Bump at Planetary Bow Shocks
Authors: Terres M. , Li Gang
Published: January 2022

At scales much larger than the ion inertial scale and the gyroradius of thermal protons, the magnetohydrodynamic (MHD) theory is well equipped to describe the nature of solar wind turbulence. The turbulent spectrum itself is defined by a power law manifesting the energy cascading process. A break in the turbulence spectrum develops near-ion scales, signaling the onset of energy dissipation. The exact mechanism for the spectral break is still a matter of debate. In this work, we use the 20 Hz Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) magnetic field data during four planetary flybys at different heliocentric distances to examine the nature of the spectral break in the solar wind. We relate the spectral break frequencies of the solar wind MHD turbulence, found in the range of 0.3–0.7 Hz, with the well-known characteristic spectral bump at frequencies ∼1 Hz upstream of planetary bow shocks. Spectral breaks and spectral bumps during three planetary flybys are identified from the MESSENGER observations, with heliocentric distances in the range of 0.3–0.7 au. The MESSENGER observations are complemented by one Magnetospheric Multiscale observation made at 1 au. We find that the ratio of the spectral bump frequency to the spectral break frequency appears to be r- and B-independent. From this, we postulate that the wavenumber of the spectral break and the frequency of the spectral bump have the same dependence on the magnetic field strength ∣B∣. The implication of our work on the nature of the break scale is discussed.