bluuebunny/crossref_metadata_2025_split huggingface dataset:
Circunstancias que limitan la expansión de las TIC
Authors: Martínez Xioyusmar 
Published: August 2022

Las Tecnologías de la Información y las Comunicación (TIC) forman parte de la cultura tecnológica que nos rodea y con la que debemos convivir. Amplían nuestras capacidades físicas y mentales, y las posibilidades de desarrollo social. En el concepto TIC se incluye no solamente la informática y sus tecnologías asociadas, telemática y multimedia, sino también los medios de comunicación de todo tipo: los medios de comunicación social ("más media") y los medios de comunicación interpersonales tradicionales con soporte tecnológico como el teléfono, fax.
Las TIC en Venezuela
Authors: Lionettis-González Yudimar 
Published: August 2022

La década de los 90 fue el principio de la transformación de la raza humana, ya que las nuevas tecnologías irrumpieron con gran fuerza en la vida hasta lograr que se dependa de ella en su totalidad. Ante de los 90, las tecnología no habían avanzado a pasos agigantados, pero hoy no dejan de evolucionar para simplificar la vida. Pero éstas han contribuido con el desarrollo de la educación o no. Algunos dirán que las TIC llegaron para simplificar la vida de los estudiantes y abrirle una gama de posibilidades para su educación, otros asumen que las mismas atentan contra la calidad de las mismas.
GJ 229B: Solving the Puzzle of the First Known T Dwarf with the APOLLO Retrieval Code
Authors: Howe Alex R. , McElwain Michael W. , Mandell Avi M. 
Published: August 2022

Abstract
GJ 229B was the first T dwarf to be discovered in 1995, and its spectrum has been more thoroughly observed than that of most other brown dwarfs. Yet a full spectroscopic analysis of its atmosphere has not been done with modern techniques. This spectrum has several peculiar features, and recent dynamical estimates of GJ 229B’s mass and orbit have disagreed widely, both of which warrant closer investigation. With a separation of tens of astronomical units from its host star, GJ 229B falls near the border of the planet and stellar population formation regimes, so its atmosphere could provide clues to formation processes for intermediate objects of this type. In an effort to resolve these questions, we performed retrievals on published spectra of GJ 229B over a wide range of wavelengths (0.5–5.1 μm) using the open-source APOLLO code. Based on these retrievals, we present a more precise mass estimate of 41.6 ± 3.3 M

J
and an effective temperature estimate of

869

−
7

+
5

K, which are more consistent with evolutionary models for brown dwarfs and suggest an older age for the system of >1.0 Gyr. We also present retrieved molecular abundances for the atmosphere, including replicating the previously observed high CO abundance, and discuss their implications for the formation and evolution of this object. This retrieval effort will give us insight into how to study other brown dwarfs and directly imaged planets, including those observed with JWST and other next-generation telescopes.
Plasma Oscillations and Kinetic Instabilities at Ion Scales in the Expanding Magnetosheath
Authors: Trávníček Pavel M. , Chaston Chris C. 
Published: August 2022

Abstract
We investigate a relationship between a decaying spectrum of magnetic field perturbations and kinetic instabilities in a slowly expanding magnetosheath plasma using two-dimensional hybrid expanding simulations in (X, Y) space. We impose an initial ambient magnetic field
B

0/B
0 = (1, 0, 0), and superimpose a flat spectrum of Alfvénic fluctuations with average amplitudes equal to δ
B = ∣B − B
0∣ ∼ 0.2B
0. The expansion leads to the development of temperature anisotropy A

p
= T

p⊥/T

p∥ > 1 (T

p⊥, T

p∥ are plasma temperatures perpendicular and parallel with respect to
B

0, respectively) and the system becomes unstable with respect to the ion cyclotron and mirror instabilities. The onset of mirror instability in the early stage of the simulation leads to the development of filaments that fill the simulation volume. The filaments represent pressure-balanced structures as they develop in the form of magnetic field (δ
B) perturbations balanced with corresponding density perturbations. Further expansion of the system leads to the thinning of these filaments, which gradually become extremely narrow. The filamentation maintains the power spectral density in δ
B
⊥ at

P

B

⊥

∼

10

−
3

B

0

2

d

p
0

(here d

p0 is the proton inertial length) over the range 0.2 < kd

p0 < 1.1. The filaments remain well developed in the form of density, magnetic field, and temperature anisotropy perturbations at t ∼ 10,000/Ω
p0 (here Ω
p0 is the initial proton gyrofrequency) and slowly dissipate when the expansion continues further.
Starspot Modeling and Flare Analysis on Selected Main-sequence M-type Stars
Authors: Bicz K. , Falewicz R. , Pietras M. , Siarkowski M. , Preś P. 
Published: August 2022

Abstract
We studied the light curves of GJ 1243, YZ CMi, and V374 Peg, as observed by TESS, for the presence of stellar spots and stellar flares. One of the main goals was to model the light curves of the spotted stars to estimate the number of spots, along with their parameters, using our original BASSMAN software. The modeled light curves were subtracted from the observations to increase the efficiency of the flare detection. The flares were detected automatically with our new dedicated software, WARPFINDER. We estimated the presence of two spots on GJ 1243, with a mean temperature of about 2800 K and a spottedness varying between 3% and 4% of the stellar surface, and two spots on V374 Peg, with a mean temperature of about 3000 K and a spottedness of about 6% of the stellar surface. On YZ CMi, we found two different models for two light curves separated in time by 1.5 yr. One of them was a three-spot model, with a mean temperature of about 3000 K and a spottedness of about 9% of the stellar surface. The second was a four-spot model, with a mean temperature of about 2800 K and a spottedness of about 7% of the stellar surface. We tested whether the flares were distributed homogeneously in phase and where there was any correlation between the presence of spots and the distribution of the flares. For YZ CMi, one spot was in anticorrelation with the distribution of the flares, while GJ 1243 shows the nonhomogeneous distribution of flares.
The GIGANTES Data Set: Precision Cosmology from Voids in the Machine-learning Era
Authors: Kreisch Christina D. , Pisani Alice , Villaescusa-Navarro Francisco , Spergel David N. , Wandelt Benjamin D. , Hamaus Nico , Bayer Adrian E. 
Published: August 2022

Abstract
We present GIGANTES, the most extensive and realistic void catalog suite ever released—containing over 1 billion cosmic voids covering a volume larger than the observable universe, more than 20 TB of data, and created by running the void finder VIDE on QUIJOTE’s halo simulations. The GIGANTES suite, spanning thousands of cosmological models, opens up the study of voids, answering compelling questions: Do voids carry unique cosmological information? How is this information correlated with galaxy information? Leveraging the large number of voids in the GIGANTES suite, our Fisher constraints demonstrate voids contain additional information, critically tightening constraints on cosmological parameters. We use traditional void summary statistics (void size function, void density profile) and the void autocorrelation function, which independently yields an error of 0.13 eV on ∑ m

ν
for a 1 h
−3 Gpc3 simulation, without cosmic microwave background priors. Combining halos and voids we forecast an error of 0.09 eV from the same volume, representing a gain of 60% compared to halos alone. Extrapolating to next generation multi-Gpc3 surveys such as the Dark Energy Spectroscopic Instrument, Euclid, the Spectro-Photometer for the History of the Universe and Ices Explorer, and the Roman Space Telescope, we expect voids should yield an independent determination of neutrino mass. Crucially, GIGANTES is the first void catalog suite expressly built for intensive machine-learning exploration. We illustrate this by training a neural network to perform likelihood-free inference on the void size function, giving a ∼20% constraint on Ωm. Cosmology problems provide an impetus to develop novel deep-learning techniques. With GIGANTES, machine learning gains an impressive data set, offering unique problems that will stimulate new techniques.
Radio Emission from UV Cet: Auroral Emission from a Stellar Magnetosphere
Authors: Bastian T. S. , Cotton W. D. , Hallinan G. 
Published: August 2022

Abstract
The archetypical flare star UV Cet was observed by MeerKAT on 2021 October 5–6. A large radio outburst with a duration of ∼2 hr was observed between 886 and 1682 MHz, with a time resolution of 8 s and a frequency resolution of 0.84 MHz, enabling sensitive dynamic spectra to be formed. The emission is characterized by three peaks containing a multitude of broadband arcs or partial arcs in the time-frequency domain. In general, the arcs are highly right-hand circularly polarized. At the end of the third peak, brief bursts occur that are significantly elliptically polarized. We present a simple model that appears to be broadly consistent with the characteristics of the radio emission from UV Cet. Briefly, the stellar magnetic field is modeled as a dipole aligned with the rotational axis of the star. The radio emission mechanism is assumed to be due to the cyclotron maser instability, where x-mode radiation near the electron gyrofrequency is amplified. While the elliptically polarized bursts may be intrinsic to the source, rather stringent limits are imposed on the plasma density in the source and along the propagation path. We suggest that the elliptically polarized radiation may instead be the result of reflection on an overdense plasma structure at some distance from the source. The radio emission from UV Cet shares both stellar and planetary attributes.
Dissecting Nearby Galaxies with piXedfit. II. Spatially Resolved Scaling Relations among Stars, Dust, and Gas
Authors: Abdurro’uf  , Lin Yen-Ting , Hirashita Hiroyuki , Morishita Takahiro , Tacchella Sandro , Wu Po-Feng , Akiyama Masayuki , Takeuchi Tsutomu T. 
Published: August 2022

Abstract
We study spatially resolved scaling relations among stars, dust, and gas in ten nearby spiral galaxies. In a preceding paper, we have derived spatially resolved properties of the stellar population and dust by a panchromatic spectral energy distribution fitting using piXedfit. Now, we investigate resolved star formation (

Σ

H

2

–ΣSFR–Σ*) and dust scaling relations. While the relations with all subgalactic regions of the galaxies are reasonably tight (σ ≲ 0.3 dex), we find that most of the scaling relations exhibit galaxy-to-galaxy variations in normalization and shape. Only two relations of Σdust–Σgas and Σdust–

Σ

H

2

do not show noticeable galaxy-to-galaxy variations among our sample galaxies. We further investigate the correlations among the scaling relations. We find significant correlations among the normalization of the

Σ

H

2

–ΣSFR–Σ* relations, which suggest that the galaxies with higher levels of resolved H2 fraction (

f

H

2

) tend to have higher levels of resolved star formation efficiency (SFE) and specific star formation rate (sSFR). We also observe that the galaxies with higher levels of resolved dust-to-stellar mass ratios tend to have higher levels of resolved sSFR, SFE, and

f

H

2

. Moreover, we find that the galaxies with higher global sSFR and less compact morphology tend to have higher levels of the resolved sSFR, SFE, and

f

H

2

, which can explain the variations in the normalization of the

Σ

H

2

–ΣSFR–Σ* relationships. Overall, we observe indications of the contributions of both global and local factors in governing the star formation process in galaxies.
The Physical Properties of Low-redshift FeLoBAL Quasars. II. The Rest-frame Optical Emission Line Properties
Authors: Leighly Karen M. , Choi Hyunseop , DeFrancesco Cora , Voelker Julianna , Terndrup Donald M. , Gallagher Sarah C. , Richards Gordon T. 
Published: August 2022

Abstract
We report the results of an analysis of the Hβ emission line region of a sample of 30 low-redshift (z < 1) iron low-ionization broad absorption line quasars (FeLoBALQs). Eleven of these objects are newly classified as FeLoBALQs. A matched sample of 132 unabsorbed quasars was analyzed in parallel. The emission lines showed the well-known anticorrelation between the [O iii] and Fe ii emission. Using a summary statistic called E1 to quantify this anticorrelation, we found that while the distribution of E1 for the unabsorbed quasars has a single peak, the FeLoBALQs have a bimodal shape in this parameter. Previous studies have shown that the line emission properties of BAL and non-BALQs are consistent; therefore, the difference in the Hβ region emission between FeLoBALQs and unabsorbed quasars is a new result. The two populations of FeLoBALQs are characterized by low and high bolometric luminosities and Eddington ratios. Some previous studies have suggested that BALQs are high accretion rate objects and therefore the discovery of the low accretion rate branch of FeLoBAL quasars was unexpected. We also found that the Hβ FWHM is systematically broader among the FeLoBALQs, implying a higher inclination viewing angle or a dearth of low velocity line emitting gas.
Geodesic Model of HF QPOs Tested for Black Holes in Spacetimes Reflecting the Effect of Surrounding Dark Matter
Authors: Stuchlík Zdeněk , Vrba Jaroslav 
Published: August 2022

Abstract
Using the simple but robust model of a shell of dark matter (DM) around a Schwarzschild black hole (BH), represented by the mass ratio of the shell and BH ΔM/M, the shell extension Δr
s and its inner radius r
s, we study the influence of DM on the spacetime structure and geodesic motion, and provide a classification of the BH+DM shell spacetimes according to the properties of the stable circular geodesics governing Keplerian disks. We focus our attention on the epicyclic motion around circular geodesics that can be related to observational phenomena in X-ray radiation from Keplerian accretion disks, assumed to be influenced by the DM shell only gravitationally. We give the frequencies of the orbital and epicyclic motions and discuss their properties in terms of the parameters governing the DM shell. Using the frequencies in relevant variants of the standard geodesic model of high-frequency quasiperiodic oscillations (HF QPOs), we test the role of DM by fitting the HF QPO data from some microquasars and active galactic nuclei with supermassive BHs where no variant of the geodesic model applied in the standard vacuum BH background is able to explain the data. We thus provide a robust review of the applicability of the geodesic model of HF QPOs, and also provide limits on the amount of DM around a BH. We demonstrate that the geodesic model could be well applied to most observations of active galactic nuclei, with strong restrictions on the amount of invisible matter around BHs.
An AGN with an Ionized Gas Outflow in a Massive Quiescent Galaxy in a Protocluster at z = 3.09
Authors: Kubo Mariko , Umehata Hideki , Matsuda Yuichi , Kajisawa Masaru , Steidel Charles C. , Yamada Toru , Tanaka Ichi , Hatsukade Bunyo , Tamura Yoichi , Nakanishi Kouichiro , Kohno Kotaro , Lee Kianhong , Matsuda Keiichi , Ao Yiping , Nagao Tohru , Yun Min S. 
Published: August 2022

Abstract
We report the detection of an ionized gas outflow from an X-ray active galactic nucleus hosted in a massive quiescent galaxy in a protocluster at z = 3.09 (J221737.29+001823.4). It is a type-2 QSO with broad (W
80 > 1000 km s−1) and strong (

log
(

L

[
OIII
]

/erg s−1) ≈ 43.4) [O iii]λ
λ 4959,5007 emission lines detected by slit spectroscopy in three-position angles using Multi-Object Infra-Red Camera and Spectrograph (MOIRCS) on the Subaru telescope and the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck-I telescope. In the all slit directions, [O iii] emission is extended to ∼15 physical kpc and indicates a powerful outflow spreading over the host galaxy. The inferred ionized gas mass outflow rate is 22 ± 3 M
⊙ yr−1. Although it is a radio source, according to the line diagnostics using Hβ, [O ii], and [O iii], photoionization by the central QSO is likely the dominant ionization mechanism rather than shocks caused by radio jets. On the other hand, the spectral energy distribution of the host galaxy is well characterized as a quiescent galaxy that has shut down star formation several hundred Myr ago. Our results suggest a scenario that QSOs are powered after the shutdown of the star formation and help complete the quenching of massive quiescent galaxies at high redshift.
A Multifluid Dust Module in Athena++: Algorithms and Numerical Tests
Authors: Huang Pinghui , Bai Xue-Ning 
Published: August 2022

Abstract
We describe the algorithm, implementation, and numerical tests of a multifluid dust module in the Athena++ magnetohydrodynamic code. The module can accommodate an arbitrary number of dust species interacting with the gas via aerodynamic drag (characterized by the stopping time), with a number of numerical solvers. In particular, we describe two second-order accurate, two-stage, fully implicit solvers that are stable in stiff regimes, including short stopping times and high dust mass loading, and they are paired with the second-order explicit van Leer and Runge–Kutta gas dynamics solvers in Athena++, respectively. Moreover, we formulate a consistent treatment of dust concentration diffusion with dust back-reaction, which incorporates momentum diffusion and ensures Galilean invariance. The new formulation and stiff drag solvers are implemented to be compatible with most of the existing features of Athena++, including different coordinate systems, mesh refinement, and shearing box and orbital advection. We present a large suite of test problems, including the streaming instability in linear and nonlinear regimes, as well as local and global settings, which demonstrate that the code achieves the desired performance. This module will be particularly useful for studies of dust dynamics and planet formation in protoplanetary disks.
Osaka Feedback Model. II. Modeling Supernova Feedback Based on High-resolution Simulations
Authors: Oku Yuri , Tomida Kengo , Nagamine Kentaro , Shimizu Ikkoh , Cen Renyue 
Published: August 2022

Abstract
Feedback from supernovae (SNe) is an essential mechanism that self-regulates the growth of galaxies, and a better model of SN feedback is still needed in galaxy-formation simulations. In the first part of this paper, using an Eulerian hydrodynamic code Athena++, we find the universal scaling relations for the time evolution of momentum and radius for a superbubble, when the momentum and time are scaled by those at the shell-formation time. In the second part of this paper, we develop a SN feedback model based on the Athena++ simulation results utilizing Voronoi tessellation around each star particle, and implement it into the GADGET3-Osaka smoothed particle hydrodynamic code. Our feedback model was demonstrated to be isotropic and conservative in terms of energy and momentum. We examined the mass/energy/metal loading factors and find that our stochastic thermal feedback model produced galactic outflow that carries metals high above the galactic plane but with weak suppression of star formation. Additional mechanical feedback further suppressed star formation and brought the simulation results into better agreement with the observations of the Kennicutt–Schmidt relation, with all the results being within the uncertainties of observed data. We argue that both thermal and mechanical feedback are necessary for the SN feedback model of galaxy evolution when an individual SN bubble is unresolved.
Mining S-PLUS for Metal-poor Stars in the Milky Way
Authors: Placco Vinicius M. , Almeida-Fernandes Felipe , Arentsen Anke , Lee Young Sun , Schoenell William , Ribeiro Tiago , Kanaan Antonio 
Published: August 2022

Abstract
This work presents the medium-resolution (R ∼ 1500) spectroscopic follow-up of 522 low-metallicity star candidates from the Southern Photometric Local Universe Survey (S-PLUS). The objects were selected from narrowband photometry, taking advantage of the metallicity-sensitive S-PLUS colors. The follow-up observations were conducted with the Blanco and Gemini South telescopes, using the COSMOS and GMOS spectrographs, respectively. The stellar atmospheric parameters (T
eff,

log

g

, and [Fe/H]), as well as carbon and α-element abundances, were calculated for the program stars in order to assess the efficacy of the color selection. Results show that

92

−
3

+
2

%

of the observed stars have [Fe/H] ≤ −1.0,

83

−
3

+
3

%

have [Fe/H] ≤ −2.0, and

15

−
3

+
3

%

have [Fe/H] ≤ −3.0, including two ultra metal-poor stars ([Fe/H] ≤ −4.0). The 80th percentile for the metallicity cumulative distribution function of the observed sample is [Fe/H] = −2.04. The sample also includes 68 carbon-enhanced metal-poor stars. Based on the calculated metallicities, further S-PLUS color cuts are proposed, which can increase the fractions of stars with [Fe/H] ≤ −1.0 and ≤ −2.0 to 98% and 88%, respectively. Such high success rates enable targeted high-resolution spectroscopic follow-up efforts, as well as provide selection criteria for fiber-fed multiplex spectroscopic surveys.
A Blind All-sky Search for Star Clusters in Gaia EDR3: 886 Clusters within 1.2 kpc of the Sun
Authors: He 何 Zhihong 治宏 , Wang 王 Kun 坤 , Luo 罗 Yangping 杨平 , Li 李 Jing 静 , Liu 刘 Xiaochen 效臣 , Jiang 蒋 Qingquan 青权 
Published: August 2022

Abstract
Although previous searches for star clusters have been very successful, many clusters are likely still omitted, especially at high-Galactic-latitude regions. In this work, based on the astrometry of Gaia EDR3, we searched nearby (ϖ > 0.8 mas) all-sky regions, obtaining 886 star clusters, of which 270 candidates have not been cataloged before. At the same time, we have presented the physical parameters of the clusters by fitting theoretical isochrones to their optical magnitudes. More halo members and expanding structures in many star clusters were also found. Most of the new objects are young clusters that are less than 100 million years old. Our work greatly increased the sample size and physical parameters of star clusters in the solar neighborhood, in particular, 46 clusters are newly found with ∣b∣ > 20°, which represents a nearly threefold increase in the number of clusters at high-Galactic-latitude regions.
Limits on Hierarchical Black Hole Mergers from the Most Negative χ
eff Systems
Authors: Fishbach Maya , Kimball Chase , Kalogera Vicky 
Published: August 2022

Abstract
It has been proposed that some black holes (BHs) in binary black hole (BBH) systems are born from “hierarchical mergers” (HMs), i.e., earlier mergers of smaller BHs. These HM products have spin magnitudes χ ∼ 0.7, and, if they are dynamically assembled into BBH systems, their spin orientations will sometimes be antialigned with the binary orbital angular momentum. In fact, as Baibhav et al. showed, ∼16% of BBH systems that include HM products will have an effective inspiral spin parameter, χ
eff < −0.3. Nevertheless, the LIGO–Virgo–KAGRA (LVK) gravitational-wave (GW) detectors have yet to observe a BBH system with χ
eff ≲ −0.2, leading to upper limits on the fraction of HM products in the population. We fit the astrophysical mass and spin distribution of BBH systems and measure the fraction of BBH systems with χ
eff < −0.3, which implies an upper limit on the HM fraction. We find that fewer than 26% of systems in the underlying BBH population include HM products (90% credibility). Even among BBH systems with primary masses m
1 = 60 M
⊙, the HM fraction is less than 69%, which may constrain the location of the pair-instability mass gap. With 300 GW events (to be expected in the LVK’s next observing run), if we fail to observe a BBH with χ
eff < −0.3, we can conclude that the HM fraction is smaller than

2.5

−
2.2

+
9.1

%

.