bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Early Phases of Supernova 2020pni: Shock Ionization of the Nitrogen-enriched Circumstellar Material
Authors: Terreran G. , Jacobson-Galán W. V. , Groh J. H. , Margutti R. , Coppejans D. L. , Dimitriadis G. , Kilpatrick C. D. , Matthews D. J. , Siebert M. R. , Angus C. R. , Brink T. G. , Filippenko A. V. , Foley R. J. , Jones D. O. , Tinyanont S. , Gall C. , Pfister H. , Zenati Y. , Ansari Z. , Auchettl K. , El-Badry K. , Magnier E. A. , Zheng W. 
Published: February 2022

Abstract
We present multiwavelength observations of the Type II SN 2020pni. Classified at ∼1.3 days after explosion, the object showed narrow (FWHM intensity <250 km s−1) recombination lines of ionized helium, nitrogen, and carbon, as typically seen in flash-spectroscopy events. Using the non-LTE radiative transfer code CMFGEN to model our first high-resolution spectrum, we infer a progenitor mass-loss rate of

M

̇

=
(
3.5
–
5.3
)
×

10

−
3

M
⊙ yr−1 (assuming a wind velocity of v

w
= 200 km s−1), estimated at a radius of R
in = 2.5 × 1014 cm. In addition, we find that the progenitor of SN 2020pni was enriched in helium and nitrogen (relative abundances in mass fractions of 0.30–0.40 and 8.2 × 10−3, respectively). Radio upper limits are also consistent with dense circumstellar material (CSM) and a mass-loss rate of

M

̇

>
5
×

10

−
4

M

☉

yr

−
1

. During the initial 4 days after first light, we also observe an increase in velocity of the hydrogen lines (from ∼250 to ∼1000 km s−1), suggesting complex CSM. The presence of dense and confined CSM, as well as its inhomogeneous structure, indicates a phase of enhanced mass loss of the progenitor of SN 2020pni during the last year before explosion. Finally, we compare SN 2020pni to a sample of other shock-photoionization events. We find no evidence of correlations among the physical parameters of the explosions and the characteristics of the CSM surrounding the progenitors of these events. This favors the idea that the mass loss experienced by massive stars during their final years could be governed by stochastic phenomena and that, at the same time, the physical mechanisms responsible for this mass loss must be common to a variety of different progenitors.
Charge State Calculation for Global Solar Wind Modeling
Authors: Szente J. , Landi E. , van der Holst B. 
Published: February 2022

Abstract
The charge state composition of the solar wind carries information about the electron temperature, density, and velocity of plasma in the solar corona that cannot always be measured with remote sensing techniques, due to limitations in instrumental sensitivity and field of view as well as line-of-sight integration issues. However, in situ measurements of the wind charge state distribution only provide the end result of the solar wind evolution from the source region to the freeze-in point. By using 3D global modeling it is possible to follow solar wind plasma parcels of different origin along the path of their journey and study the evolution of their charge states as well as the driving physical processes. For this purpose, we implemented nonequilibrium ionization calculations within the Space Weather Modeling Framework’s solar corona and inner heliosphere modules, to the Alfvén Wave Solar Model (AWSoM). The charge state calculations are carried out parallel to the AWSoM calculations, including all the elements and ions whose ionization-recombination rates are included in the CHIANTI database, namely, from H to Zn. In this work, we describe the implementation of the charge state calculation, and compare simulation results to in situ measurements from the Advanced Composition Explorer and Ulysses spacecraft, and study charge state evolution of plasma parcels along different wind trajectories and wind types.
Streaming Instabilities in Accreting and Magnetized Laminar Protoplanetary Disks
Authors: Lin 林 Min-Kai 明楷 , Hsu 徐 Chun-Yen 峻彥 
Published: February 2022

Abstract
The streaming instability (SI) is one of the most promising pathways to the formation of planetesimals from pebbles. Understanding how this instability operates under realistic conditions expected in protoplanetary disks (PPDs) is therefore crucial to assess the efficiency of planet formation. Contemporary models of PPDs show that magnetic fields are key to driving gas accretion through large-scale, laminar magnetic stresses. However, the effect of such magnetic fields on the SI has not been examined in detail. To this end, we study the stability of dusty, magneftized gas in a protoplanetary disk. We find the SI can be enhanced by passive magnetic torques and even persist in the absence of a global radial pressure gradient. In this case, instability is attributed to the azimuthal drift between dust and gas, unlike the classical SI, which is driven by radial drift. This suggests that the SI can remain effective inside dust-trapping pressure bumps in accreting disks. When a live vertical field is considered, we find the magneto-rotational instability can be damped by dust feedback, while the classic SI can be stabilized by magnetic perturbations. We also find that Alfvén waves can be destabilized by dust–gas drift, but this instability requires nearly ideal conditions. We discuss the possible implications of these results for dust dynamics and planetesimal formation in PPDs.
Fluxgate Magnetometer Offset Vector Determination Using Current Sheets in the Solar Wind
Authors: Wang Guoqiang , Pan Zonghao 
Published: February 2022

Abstract
The zero offset of the fluxgate magnetometer (FGM) on board the spacecraft varies slowly with time, therefore the FGM needs regular in-flight calibration. There are abundant physical phenomena in the solar wind, such as waves, mirror mode structures, and current sheets. Several in-flight calibration methods have been developed based on the properties of Alfvén waves or mirror mode structures instead of current sheets. Here, we develop a method to determine the zero offset
O
using current sheets in the solar wind, which is based on an assumption that the magnetic field in the normal direction of the current sheet is zero. The nonzero magnetic field in the normal direction is the projection of
O
, therefore we can obtain the component of
O
in the normal direction. In the offset cube, the zero offset is expected to be in a plane, which is referred to as the optimal offset plane (OOP). Each current sheet can obtain an OOP in the offset cube. At least three nonparallel OOPs must be used to determine the zero offset. We test our method by using data from the Magnetospheric Multiscale mission and find that our method is able to determine the zero offset. Our method can simultaneously use Alfvén waves, mirror mode structures, and current sheets to determine the zero offset, thus it might be a useful tool to perform the in-flight calibration of the FGM for solar wind monitors.
Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453
Authors: Quenneville Matthew E. , Liepold Emily R. , Ma Chung-Pei 
Published: February 2022

Abstract
Most stellar-dynamical determinations of the masses of nearby supermassive black holes (SMBHs) have been obtained with the orbit superposition technique under the assumption of axisymmetry. However, few galaxies—in particular massive early-type galaxies—obey exact axisymmetry. Here we present a revised orbit superposition code and a new approach for dynamically determining the intrinsic shapes and mass parameters of triaxial galaxies based on spatially resolved stellar kinematic data. The triaxial TriOS code described here corrects an error in the original van den Bosch et al. code that gives rise to incorrect projections for most orbits in triaxial models and can significantly impact parameter search results. The revised code also contains significant improvements in orbit sampling, mass constraints, and run time. Furthermore, we introduce two new parameter-searching strategies—a new set of triaxial shape parameters and a novel grid-free sampling technique—that together lead to a remarkable gain in efficiency in locating the best-fit model. We apply the updated code and search method to NGC 1453, a fast-rotating massive elliptical galaxy. A full 6D parameter search finds

p
=
b

/

a
=

0.933

−
0.015

+
0.014

and q = c/a = 0.779 ± 0.012 for the intrinsic axis ratios and T = 0.33 ± 0.06 for the triaxiality parameter. Despite the deviations from axisymmetry, the best-fit SMBH mass, stellar mass-to-light ratio, and dark matter enclosed mass for NGC 1453 are consistent with the axisymmetric results. More comparisons between axisymmetric and triaxial modeling are needed before drawing general conclusions.
The Stellar-age Dependence of X-Ray Emission from Normal Star-forming Galaxies in the GOODS Fields
Authors: Gilbertson Woodrow , Lehmer Bret D. , Doore Keith , Eufrasio Rafael T. , Basu-Zych Antara , Brandt William N. , Fragos Tassos , Garofali Kristen , Kovlakas Konstantinos , Luo Bin , Tozzi Paolo , Vito Fabio , Williams Benjamin F. , Xue Yongquan 
Published: February 2022

Abstract
The Chandra Deep Field-South and North surveys (CDFs) provide unique windows into the cosmic history of X-ray emission from normal (nonactive) galaxies. Scaling relations of normal-galaxy X-ray luminosity (L
X) with star formation rate (SFR) and stellar mass (M
⋆) have been used to show that the formation rates of low-mass and high-mass X-ray binaries (LMXBs and HMXBs, respectively) evolve with redshift across z ≈ 0–2 following L
HMXB/SFR ∝ (1 + z) and L
LMXB/M
⋆ ∝ (1 + z)2−3. However, these measurements alone do not directly reveal the physical mechanisms behind the redshift evolution of X-ray binaries (XRBs). We derive star formation histories for a sample of 344 normal galaxies in the CDFs, using spectral energy distribution (SED) fitting of FUV-to-FIR photometric data, and construct a self-consistent, age-dependent model of the X-ray emission from the galaxies. Our model quantifies how X-ray emission from hot gas and XRB populations vary as functions of host stellar-population age. We find that (1) the ratio L
X/M
⋆ declines by a factor of ∼1000 from 0 to 10 Gyr and (2) the X-ray SED becomes harder with increasing age, consistent with a scenario in which the hot gas contribution to the X-ray SED declines quickly for ages above 10 Myr. When dividing our sample into subsets based on metallicity, we find some indication that L
X/M
⋆ is elevated for low-metallicity galaxies, consistent with recent studies of X-ray scaling relations. However, additional statistical constraints are required to quantify both the age and metallicity dependence of X-ray emission from star-forming galaxies.
The Effects of Cosmic-Ray Diffusion and Radiative Cooling on the Galactic Wind of the Milky Way
Authors: Shimoda Jiro , Inutsuka Shu-ichiro 
Published: February 2022

Abstract
The effects of cosmic-ray diffusion and radiative cooling on the structure of the Galactic wind are studied using a steady-state approximation. It is known that realistic cooling processes suppress the wind from launching. The effects of cosmic-ray diffusion are also supposed to be unfavorable for launching the wind. Both of these effects have not been studied simultaneously in a steady-state approximation of the wind. We find 327,254 solutions of the steady-state Galactic wind and confirm that: the effect of the cosmic-ray pressure depends on the Alfvén Mach number, the mass flux carried by the wind does not depend on the cosmic-ray pressure directly (but depends on the thermal pressure), and the typical conditions found in the Galaxy may correspond to the wind solution that provides metal-polluted matter at a height of ∼300 kpc from the disk.
Multiband Emission up to PeV Energy from the Crab Nebula in a Spatially Dependent Lepto-hadronic Model
Authors: Peng Qi-Yong , Bao Bi-Wen , Lu Fang-Wu , Zhang Li 
Published: February 2022

Abstract
Multiband emissions from radio to ultra-high-energy gamma-rays in the Crab Nebula have been detected. To explain the observed results, nonthermal photon production in the Crab Nebula is carefully studied in a spatially dependent lepto-hadronic model. In our model, the dynamical evolution of the pulsar wind nebula (PWN) is simulated in a spherically symmetric system. Both electrons and protons are accelerated at the termination shock. The relevant particle propagation equations, as well as the photon evolving equation, are simultaneously solved. For the Crab Nebula, our results reveal that the observed multiband photon spectra can be reproduced with reasonable model parameters. In particular, the photons with energy ≳200 TeV are mainly contributed to by the hadronic component via proton–proton interaction. The contribution of the hadronic component depends on both proton spectral index α
p and number density n
H of the medium within the PWN. Additionally, high-energy neutrino fluxes are predicted with variable proton spectral indices. The predicted fluxes are not only far below the sensitivities of current neutrino observatories but also beneath the atmospheric neutrino background with energy less than ∼40 TeV. Moreover, the calculated radial profiles of surface brightness and spectral index are presented.
Polarization Spectrum of Near-Infrared Zodiacal Light Observed with CIBER
Authors: Takimoto Kohji , Arai Toshiaki , Matsuura Shuji , Bock James J. , Cooray Asantha , Feder Richard M. , Korngut Phillip M. , Lanz Alicia , Lee Dae Hee , Matsumoto Toshio , Nguyen Chi H. , Onishi Yosuke , Sano Kei , Shirahata Mai , Takahashi Aoi , Tsumura Kohji , Zemcov Michael 
Published: February 2022

Abstract
We report the first measurement of the zodiacal light (ZL) polarization spectrum in the near-infrared between 0.8 and 1.8 μm. Using the low-resolution spectrometer on board the Cosmic Infrared Background Experiment, calibrated for absolute spectrophotometry and spectropolarimetry, we acquire long-slit polarization spectral images of the total diffuse sky brightness toward five fields. To extract the ZL spectrum, we subtract the contribution of other diffuse radiation, such as the diffuse galactic light, the integrated starlight, and the extragalactic background light. The measured ZL polarization spectrum shows little wavelength dependence in the near-infrared, and the degree of polarization clearly varies as a function of the ecliptic coordinates and solar elongation. Among the observed fields, the North Ecliptic Pole shows the maximum degree of polarization of ∼20%, which is consistent with an earlier observation from the Diffuse Infrared Background Experiment on board on the Cosmic Background Explorer. The measured degree of polarization and its solar elongation dependence are reproduced by an empirical scattering model in the visible band and also by a Mie scattering model for large absorptive particles, while a Rayleigh scattering model is ruled out. All of our results suggest that the interplanetary dust is dominated by large particles.
Monte Carlo Study of Electron and Positron Cosmic-Ray Propagation with the CALET Spectrum
Authors: Asano Katsuaki , Asaoka Yoichi , Akaike Yosui , Kawanaka Norita , Kohri Kazunori , Motz Holger M. , Terasawa Toshio 
Published: February 2022

Abstract
Focusing on the electron and positron spectrum measured with the Calorimetric Electron Telescope (CALET), which shows characteristic structures, we calculate the flux contributions of cosmic rays that have escaped from randomly appearing supernova remnants. We adopt a Monte Carlo method to take into account the stochastic nature of the appearance of nearby sources. We find that without a complicated energy dependence of the diffusion coefficient, simple power-law diffusion coefficients can produce spectra similar to the CALET spectrum, even with a dispersion in the injection index. The positron component measured with AMS-02 is consistent with a bump-like structure around 300 GeV in the CALET spectrum. One to three nearby supernovae can contribute up to a few tens of percent of the CALET flux at 2–4 TeV, while ten or more unknown and distant (≳500 pc) supernovae account for the remaining several tens of percent of the flux. The CALET spectrum, showing a sharp drop at ∼1 TeV, allows for a contribution of cosmic rays from an extraordinary event that occurred ∼400 kyr ago. This type of event releases electrons/positrons with a total energy more than 10 times the average energy for usual supernovae, and its occurrence rate is lower than one three-hundredth of the usual supernova rate.
Powering Stellar Magnetism: Energy Transfers in Cyclic Dynamos of Sun-like Stars
Authors: Brun Allan Sacha , Strugarek Antoine , Noraz Quentin , Perri Barbara , Varela Jacobo , Augustson Kyle , Charbonneau Paul , Toomre Juri 
Published: February 2022

Abstract
We use the anelastic spherical harmonic code to model the convective dynamo of solar-type stars. Based on a series of 15 3D MHD simulations spanning four bins in rotation and mass, we show what mechanisms are at work in these stellar dynamos with and without magnetic cycles and how global stellar parameters affect the outcome. We also derive scaling laws for the differential rotation and magnetic field based on these simulations. We find a weaker trend between differential rotation and stellar rotation rate, (

Δ
Ω
∝

(
∣
Ω
∣

/

Ω

⊙

)

0.46

) in the MHD solutions than in their HD counterpart

∣
Ω
∣

/

Ω

⊙

0.66

), yielding a better agreement with the observational trends based on power laws. We find that for a fluid Rossby number between 0.15 ≲ Ro
f ≲ 0.65, the solutions possess long magnetic cycle, if Ro
f ≲ 0.42 a short cycle and if Ro
f ≳ 1 (antisolar-like differential rotation), a statistically steady state. We show that short-cycle dynamos follow the classical Parker–Yoshimura rule whereas the long-cycle period ones do not. We also find efficient energy transfer between reservoirs, leading to the conversion of several percent of the star's luminosity into magnetic energy that could provide enough free energy to sustain intense eruptive behavior at the star’s surface. We further demonstrate that the Rossby number dependency of the large-scale surface magnetic field in the simulation (

B

L
,
surf

∼

Ro

f

−
1.26

) agrees better with observations (

B

V

∼

Ro

s

−
1.4
±
0.1

) and differs from dynamo scaling based on the global magnetic energy (

B

bulk

∼

Ro

f

−
0.5

).
A Search of the Full Six Years of the Dark Energy Survey for Outer Solar System Objects
Authors: Bernardinelli Pedro H. , Bernstein Gary M. , Sako Masao , Yanny Brian , Aguena M. , Allam S. , Andrade-Oliveira F. , Bertin E. , Brooks D. , Buckley-Geer E. , Burke D. L. , Rosell A. Carnero , Carrasco Kind M. , Carretero J. , Conselice C. , Costanzi M. , da Costa L. N. , De Vicente J. , Desai S. , Diehl H. T. , Dietrich J. P. , Doel P. , Eckert K. , Everett S. , Ferrero I. , Flaugher B. , Fosalba P. , Frieman J. , García-Bellido J. , Gerdes D. W. , Gruen D. , Gruendl R. A. , Gschwend J. , Hinton S. R. , Hollowood D. L. , Honscheid K. , James D. J. , Kent S. , Kuehn K. , Kuropatkin N. , Lahav O. , Maia M. A. G. , March M. , Menanteau F. , Miquel R. , Morgan R. , Myles J. , Ogando R. L. C. , Palmese A. , Paz-Chinchón F. , Pieres A. , Malagón A. A. Plazas , Romer A. K. , Roodman A. , Sanchez E. , Scarpine V. , Schubnell M. , Serrano S. , Sevilla-Noarbe I. , Smith M. , Soares-Santos M. , Suchyta E. , Swanson M. E. C. , Tarle G. , To C. , Varga T. N. , Walker A. R. ,   (The DES Collaboration)
Published: February 2022

Abstract
We present a search for outer solar system objects in the 6 yr of data from the Dark Energy Survey (DES). The DES covered a contiguous 5000 deg2 of the southern sky with ≈80,000 3 deg2 exposures in the grizY filters between 2013 and 2019. This search yielded 812 trans-Neptunian objects (TNOs), one Centaur and one Oort cloud comet, 458 reported here for the first time. We present methodology that builds upon our previous search on the first 4 yr of data. All images were reprocessed with an optimized detection pipeline that leads to an average completeness gain of 0.47 mag per exposure, as well as improved transient catalog production and algorithms for linkage of detections into orbits. All objects were verified by visual inspection and by the “sub-threshold significance,” the signal-to-noise ratio in the stack of images in which its presence is indicated by the orbit, but no detection was reported. This yields a pure catalog complete to r ≈ 23.8 mag and distances 29 < d < 2500 au. The TNOs have minimum (median) of 7 (12) nights’ detections and arcs of 1.1 (4.2) yr, and will have grizY magnitudes available in a further publication. We present software for simulating our observational biases for comparisons of models to our detections. Initial inferences demonstrating the catalog’s statistical power are: the data are inconsistent with the CFEPS-L7 model for the classical Kuiper Belt; the 16 “extreme” TNOs (a > 150 au, q > 30 au) are consistent with the null hypothesis of azimuthal isotropy; and nonresonant TNOs with q > 38 au, a > 50 au show a significant tendency to be sunward of major mean-motion resonances.
Current distribution of Zostera seagrass meadows along the Bulgarian Black Sea coast (SW Black Sea, Bulgaria) (2010-2020)
Authors: Berov Dimitar , Klayn Stefania , Deyanova Diana , Karamfilov Ventzislav 
Published: February 2022

The current distribution of Zostera spp. seagrass meadows along the Bulgarian Black Sea coast was studied. We used a combination of historical and recent observations of the habitat along the studied coastline. Remote sensing data (satellite images, sonar side-scans) was groundtruthed with georeferenced drop camera observations, scuba diving sampling and georeferenced scuba diving photo and video transects.
Тhe total area of the habitat type ‘MB548 - Black Sea seagrass meadows on lower infralittoral sands’ (EUNIS habitat type list 2019) in the study area is 916.9 ha, of which only 17.9 ha are in man-made sheltered environments (harbours). All seagrass meadows identified in 1978-79 were also located during the current survey, despite the increased eutrophication pressure and overall degradation of benthic habitats in the western Black Sea during the 1980s and early 1990s.
Collaborative Entrepreneurship: How women entrepreneurs ‘do’ networking
Authors: Constantinidis Christina 
Published: February 2022

Les réseaux d’affaires des femmes ont tendance à être dépeints comme secondaires, ou comme désavantageant les femmes en termes de réussite entrepreneuriale. En remettant en question les opinions courantes sur le genre et les réseaux de femmes entrepreneurs, cette étude révèle le rôle clé des réseaux de femmes dans la création et le développement de relations d’affaires solides et durables. Nous présentons l’« entrepreneuriat collaboratif des femmes » comme une puissante pratique de mise en réseau féministe. Les résultats de la recherche sont basés sur une série d’entretiens qualitatifs approfondis avec dix dyades de femmes entrepreneurs, qui se sont rencontrées par le biais d’un réseau de femmes au Luxembourg et qui ont travaillé en étroite collaboration au fil des ans. À travers trois bénéfices clés liés à la sororité, l’autonomisation et l’innovation, l’entrepreneuriat collaboratif féminin apparaît comme particulièrement adapté au contexte économique contemporain.