bluuebunny/crossref_metadata_2025_split huggingface dataset:
Propagation Effects in the FRB 20121102A Spectra
Authors: Levkov D. G. , Panin A. G. , Tkachev I. I. 
Published: January 2022

Abstract
We advance theoretical methods for studying propagation effects in fast radio burst (FRB) spectra. We derive their autocorrelation function in the model with diffractive lensing and strong Kolmogorov-type scintillations and analytically obtain the spectra lensed on different plasma density profiles. With these tools, we reanalyze the highest frequency 4–8 GHz data of Gajjar et al. for the repeating FRB 20121102A (FRB 121102). In the data, we discover, first, a remarkable spectral structure of almost equidistant peaks separated by 95 ± 16 MHz. We suggest that it can originate from diffractive lensing of the FRB signals on a compact gravitating object of mass 10−4
M
⊙ or on a plasma underdensity near the source. Second, the spectra include erratic interstellar, presumably Milky Way scintillations. We extract their decorrelation bandwidth 3.3 ± 0.6 MHz at reference frequency 6 GHz. The third feature is a GHz-scale pattern that, as we find, linearly drifts with time and presumably represents a wideband propagation effect, e.g., GHz-scale scintillations. Fourth, many spectra are dominated by a narrow peak at 7.1 GHz. We suggest that it can be caused by propagation through a plasma lens, e.g., in the host galaxy. Fifth, separating the propagation effects, we give strong arguments that the intrinsic progenitor spectrum has a narrow GHz bandwidth and variable central frequency. This confirms expectations from the previous observations. We discuss alternative interpretations of the above spectral features.
Microstructural and Chemical Investigations of Presolar Silicates from Diverse Stellar Environments
Authors: Sanghani Manish N. , Lajaunie Luc , Marhas Kuljeet Kaur , Rickard William D. A. , Hsiao Silver Sung-Yun , Peeters Zan , Shang Hsien , Lee Der-Chuen , Calvino José. J. , Bizzarro Martin 
Published: January 2022

Abstract
We report the structural and chemical investigation of nine presolar silicate grains from the CH3/CBb3 chondrite Isheyevo and CR2 chondrite Northwest Africa (NWA) 801. Five of these grains belong to group 1, likely condensed in low- to intermediate-mass asymptotic giant branch (AGB) stars, super-AGB stars, or core-collapse supernovae, while the remaining four grains belong to group 4 and have a supernova origin. The advanced transmission electron microscopy and associated electron spectroscopy analyses show a diverse range of chemical and structural compositions for presolar silicates. Two GEMS (glass with embedded metal and sulfide)-like silicates, each from different groups, condensed under nonequilibrium conditions in stellar outflows. Two nonstoichiometric silicates from group 1 have dissimilar formation and alteration histories. An amorphous silicate from group 1 with olivine-like [(Mg,Fe)2SiO4] composition likely formed as a crystalline olivine that subsequently amorphized in the interstellar medium. An oldhamite (CaS) grain within a stoichiometric enstatite (MgSiO3) from group 1 probably formed by heterogeneous condensation in circumstellar outflows. Of the two crystalline grains from group 4, one is an antigorite [(Mg,Fe)3Si2O5(OH)4], while the other is a nontronite [Na,Fe2(Si,Al)4O10(OH)2.nH2O], both formed as a crystalline forsterite and later altered to have hydrated silicate composition. A group-4 silicate has a chemical composition similar to a low Ca-pyroxene [(Ca,Mg)(Si,Al)2O6]. Our data imply that presolar grains from different groups can have a similar range of grain-formation conditions.
EMPRESS. IV. Extremely Metal-poor Galaxies Including Very Low-mass Primordial Systems with M
* = 104–105
M
⊙ and 2%–3% (O/H): High (Fe/O) Suggestive of Metal Enrichment by Hypernovae/Pair-instability Supernovae
Authors: Isobe Yuki , Ouchi Masami , Suzuki Akihiro , Moriya Takashi J. , Nakajima Kimihiko , Nomoto Ken’ichi , Rauch Michael , Harikane Yuichi , Kojima Takashi , Ono Yoshiaki , Fujimoto Seiji , Inoue Akio K. , Kim Ji Hoon , Komiyama Yutaka , Kusakabe Haruka , Lee Chien-Hsiu , Maseda Michael , Matthee Jorryt , Michel-Dansac Leo , Nagao Tohru , Nanayakkara Themiya , Nishigaki Moka , Onodera Masato , Sugahara Yuma , Xu Yi 
Published: January 2022

Abstract
We present Keck/LRIS follow-up spectroscopy for 13 photometric candidates of extremely metal-poor galaxies (EMPGs) selected by a machine-learning technique applied to the deep (∼26 AB mag) optical and wide-area (∼500 deg2) Subaru imaging data in the EMPRESS survey. Nine out of the 13 candidates are EMPGs with an oxygen abundance (O/H) less than ∼10% solar value (O/H)⊙, and four sources are contaminants of moderately metal-rich galaxies or no emission-line objects. Notably, two out of the nine EMPGs have extremely low stellar masses and oxygen abundances of 5 × 104–7 × 105
M
⊙ and 2%–3% (O/H)⊙, respectively. With a sample of five EMPGs with (Fe/O) measurements, two (three) of which are taken from this study (the literature), we confirm that two EMPGs with the lowest (O/H) ratios of ∼2% (O/H)⊙ show high (Fe/O) ratios of ∼0.1, close to the solar abundance ratio. Comparing galaxy chemical enrichment models, we find that the two EMPGs cannot be explained by a scenario of metal-poor gas accretion/episodic star formation history due to their low (N/O) ratios. We conclude that the two EMPGs can be reproduced by the inclusion of bright hypernovae and/or hypothetical pair-instability supernovae (SNe) preferentially produced in a metal-poor environment. This conclusion implies that primordial galaxies at z ∼ 10 could have a high abundance of Fe that did not originate from Type Ia SNe with delays and that Fe may not serve as a cosmic clock for primordial galaxies.
Binary Formation in the Orion Nebula Cluster: Exploring the Substellar Limit
Authors: De Furio Matthew , Meyer Michael R. , Reiter Megan , Monnier John , Kraus Adam , Dupuy Trent 
Published: January 2022

Abstract
We present results constraining the multiplicity of the very low mass stars and substellar objects in the Orion Nebula Cluster (ONC). Our sample covers primary masses 0.012–0.1 M
⊙ using archival Hubble Space Telescope data obtained with the Advanced Camera for Surveys using multiple filters. Studying the binary populations of clusters provides valuable constraints of how the birth environment affects binary formation and evolution. Prior surveys have shown that the binary populations of high-mass, high-density star clusters like the ONC may substantially differ from those in low-mass associations. Very low mass stellar and substellar binaries at wide separations, >20 au, are statistically rare in the Galactic field and have been identified in stellar associations like Taurus-Auriga and Ophiuchus. They also may be susceptible to dynamical interactions, and their formation may be suppressed by feedback from ongoing star formation. We implement a double point-spread function (PSF) fitting algorithm using empirical, position-dependent PSF models to search for binary companions at projected separations >10 au (0.″025). With this technique, we identify seven very low mass binaries, five of which are new detections, resulting in a binary frequency of

12

−
3.2

+
6

%

over mass ratios of 0.5–1.0 and projected separations of 20–200 au. We find an excess of very low mass binaries in the ONC compared to the Galactic field, with a probability of 10−6 that the populations are statistically consistent. The substellar population of the ONC may require further dynamical processing of the lowest binding energy binaries to resemble the field population.
Detection of Gravity Modes in RR Lyrae Stars
Authors: Chadid Merieme 
Published: January 2022

Abstract
We report the detection of gravity modes in RR Lyrae stars. Thanks to Photometer AntarctIca eXtinction (PAIX), the first Antarctic polar photometer. Unprecedented and uninterrupted UBVRI time-series photometric ground-based data are collected during 150 days from the highest plateau of Antarctica. PAIX light-curve analyses reveal an even richer power spectrum with mixed modes in RR Lyrae stars. The nonlinear nature of several dominant peaks, showing lower and higher frequencies, occurs around the dominant fundamental radial pressure mode. These lower frequencies and harmonics linearly interact with the dominant fundamental radial pressure mode and its second and third overtone pressure modes, as well. Half-integer frequencies are also detected, likewise side-peak structures, demonstrating that HH Puppis is a bona-fide Blazhko star. Fourier correlations are used to derive underlying physical characteristics for HH Puppis. The most striking finding is the direct detection of gravity waves. We interpret the excitation mechanism of gravity waves in RR Lyrae stars by the penetrative convection-driving mechanism. We demonstrate that RR Lyrae stars’ pulsation is excited by several distinct mechanisms, and hence RR Lyrae stars are simultaneously g-mode and p-mode pulsators. Our discoveries make RR Lyrae stars very challenging stellar objects, and provide their potential to undergo at the same time g and p modes toward an advancement of the theory of stellar evolution and a better understanding of the universe.
Deep Learning of the Eddington Tensor in Core-collapse Supernova Simulation
Authors: Harada Akira , Nishikawa Shota , Yamada Shoichi 
Published: January 2022

Abstract
We trained deep neural networks (DNNs) as a function of the neutrino energy density, flux, and the fluid velocity to reproduce the Eddington tensor for neutrinos obtained in our first-principles core-collapse supernova simulation. Although the moment method, which is one of the most popular approximations for neutrino transport, requires a closure relation, none of the analytical closure relations commonly employed in the literature capture all aspects of the neutrino angular distribution in momentum space. In this paper, we develop a closure relation by using DNNs that take the neutrino energy density, flux, and the fluid velocity as the inputs and the Eddington tensor as the output. We consider two kinds of DNNs: a conventional DNN, named a component-wise neural network (CWNN), and a tensor-basis neural network (TBNN). We find that the diagonal component of the Eddington tensor is better reproduced by the DNNs than the M1 closure relation, especially for low to intermediate energies. For the off-diagonal component, the DNNs agree better with the Boltzmann solver than the M1 closure relation at large radii. In the comparison between the two DNNs, the TBNN displays slightly better performance than the CWNN. With these new closure relations at hand, based on DNNs that well reproduce the Eddington tensor at much lower costs, we have opened up a new possibility for the moment method.
From the Fire: A Deeper Look at the Phoenix Stream
Authors: Tavangar K. , Ferguson P. , Shipp N. , Drlica-Wagner A. , Koposov S. , Erkal D. , Balbinot E. , García-Bellido J. , Kuehn K. , Lewis G. F. , Li T. S. , Mau S. , Pace A. B. , Riley A. H. , Abbott T. M. C. , Aguena M. , Allam S. , Andrade-Oliveira F. , Annis J. , Bertin E. , Brooks D. , Burke D. L. , Carnero Rosell A. , Carrasco Kind M. , Carretero J. , Costanzi M. , da Costa L. N. , Pereira M. E. S. , De Vicente J. , Diehl H. T. , Everett S. , Ferrero I. , Flaugher B. , Frieman J. , Gaztanaga E. , Gerdes D. W. , Gruen D. , Gruendl R. A. , Gschwend J. , Gutierrez G. , Hinton S. R. , Hollowood D. L. , Honscheid K. , James D. J. , Kuropatkin N. , Maia M. A. G. , Marshall J. L. , Menanteau F. , Miquel R. , Morgan R. , Ogando R. L. C. , Palmese A. , Paz-Chinchón F. , Pieres A. , Plazas Malagón A. A. , Rodriguez-Monroy M. , Sanchez E. , Scarpine V. , Serrano S. , Sevilla-Noarbe I. , Smith M. , Suchyta E. , Swanson M. E. C. , Tarle G. , To C. , Varga T. N. , Walker A. R. ,   (DES Collaboration)
Published: January 2022

Abstract
We use 6 yr of data from the Dark Energy Survey to perform a detailed photometric characterization of the Phoenix stellar stream, a 15° long, thin, dynamically cold, low-metallicity stellar system in the Southern Hemisphere. We use natural splines, a nonparametric modeling technique, to simultaneously fit the stream track, width, and linear density. This updated stream model allows us to improve measurements of the heliocentric distance (17.4 ± 0.1 (stat.) ±0.8 (sys.) kpc) and distance gradient (−0.009 ± 0.006 kpc deg−1) of Phoenix, which corresponds to a small change of 0.13 ± 0.09 kpc in heliocentric distance along the length of the stream. We measure linear intensity variations on degree scales, as well as deviations in the stream track on ∼2° scales, suggesting that the stream may have been disturbed during its formation and/or evolution. We recover three peaks and one gap in linear intensity along with fluctuations in the stream track. Compared to other thin streams, the Phoenix stream shows more fluctuations and, consequently, the study of Phoenix offers a unique perspective on gravitational perturbations of stellar streams. We discuss possible sources of perturbations to Phoenix, including baryonic structures in the Galaxy and dark matter subhalos.
The Preprocessing of Galaxies in the Early Stages of Cluster Formation in Abell 1882 at z = 0.139
Authors: Sengupta Aparajita , Keel William C. , Morrison Glenn , Windhorst Rogier A. , Miller Neal , Smith Brent 
Published: January 2022

Abstract
A rare opportunity to distinguish between internal and environmental effects on galaxy evolution is afforded by “SuperGroups,” systems that are rich and massive, but include several comparably rich substructures, surrounded by filaments. We present here a multiwavelength photometric and spectroscopic study of the galaxy population in the SuperGroup Abell 1882 (A1882) at z = 0.139, combining new data from the MMT and Hectospec with archival results from the Galaxy And Mass Assembly survey, the Sloan Digital Sky Survey, the Nasa/IPAC Extragalactic Database, the Gemini Multi-Object Spectrograph, and the Galaxy Evolution Explorer. These provide spectroscopic classifications for 526 member galaxies, across wide ranges of local density and velocity dispersion. We identify three prominent filaments along which galaxies seem to be entering the SuperGroup (mostly in E–W directions). A1882 has a well-populated red sequence, containing most galaxies with stellar mass >1010.5
M
Sun, and a pronounced color–density relation even within its substructures. Thus, galaxy evolution responds to the external environment as strongly in these unrelaxed systems as we find in rich and relaxed clusters. From these data, local density remains the primary factor, with a secondary role for distance from the inferred center of the entire structure’s potential well. The effects on star formation, as traced by optical and near-UV colors, depend on galaxy mass. We see changes in lower-mass galaxies (M < 1010.5
M
Sun) at four times the virial radius of major substructures, while the more massive near-UV Green Valley galaxies show low levels of star formation within two virial radii. The suppression of star formation (“quenching”) occurs in the infall regions of these structures even before the galaxies enter the denser group environment.
Planetary Accretion Shocks with a Realistic Equation of State
Authors: Chen 陈 Zhuo 卓 , Bai 白 Xuening 雪宁 
Published: January 2022

Abstract
The final stage of gas giant formation involves accreting gas from the parent protoplanetary disk. In general, the infalling gas likely approaches a freefall velocity, creating an accretion shock, leading to strong shock heating and radiation. We investigate the kinematics and energetics of such accretion shocks using 1D radiation hydrodynamic simulations. Our simulations feature the first self-consistent treatment of hydrogen dissociation and ionization, radiation transport, and realistic gray opacity. By exploring a broad range of giant-planet masses (0.1–3M
J) and accretion rates (10−3–10−2
M
⊕ yr−1), we focus on global shock efficiency and the final entropy of the accreted gas. We find that radiation from the accretion shock can fully disassociate the molecular hydrogen of the incoming gas when the shock luminosity is above a critical luminosity. Meanwhile, the post-shock entropy generally falls into “cold” (≲12k
B/m
H) and “hot” (≳16k
B/m
H) groups which depend on the extent of the endothermic process of H2 dissociation. While 2D or 3D simulations are needed for more realistic understandings of the accretion process, this distinction likely carries over and sheds light on the interpretation of young direct imaging planets.
La Gazeta de Vitoria (23 de agosto – 11 de noviembre de 1808)
Authors: Dufour Gérard , Viana Patxi 
Published: January 2022

Cela fait presque 30 ans que les historiens ont été informés de la présence, à la bibliothèque du Séminaire Diocésain de Vitoria-Gasteiz, d’une collection complète du journal officiel que fit publier Joseph I quand il dut, avec ce qui lui restait de sa cour, se réfugier dans la capitale de l’Alava, la Gazeta de la Corte, qui devint rapidement la Gazeta de Vitoria. Et pourtant, ce périodique n’a été jusqu’à présent ni utilisé, ni analysé par les chercheurs. Cet article vient combler cette lacune et le lecteur y trouvera la description de cette publication et de son rythme de parution, des précisions sur ceux qui purent en l’être l’éditeur et les rédacteurs ; une analyse de son contenu qui révèle que la Gazeta de Vitoria fut également une gazette de l’Empire sous contrôle de l’empereur des français et roi d’Italie, le rôle que Joseph I joua dans son orientation, sa diffusion dans tout le royaume, ( aussi bien les territoires occupés par les troupe impériales que dans l’Espagne libre) : son écho dans la presse française et sa disparition quand Joseph abandonna Vitoria à la suite de son frère Napoléon. Deux appendices complètent ce travail : le premier est constitué par la liste des décrets et ordonnances signés par le roi publiés dans la gazette ; le second par la publication de l’intégralité des numéros conservés à la bibliothèque diocésaine de Vitoria-Gasteiz, exemplaires qui témoignent de la naissance de la presse de cette ville et, par là-même, du Pays Basque.
¿Identidades en crisis? los discursos identitarios en la prensa espectatorial española y francesa
Authors: Hobisch Elisabeth 
Published: January 2022

L’objectif de cet article est d’étudier le discours sur l’identité nationale dans les spectateurs espagnols et francophones. Ce genre journalistique littéraire est né en Angleterre au début du XVIIIe siècle et a été diffusé dans le monde occidental. Il sert de laboratoire littéraire aux auteures et auteurs ainsi qu’aux lecteurs et anticipe les stratégies littéraires qui marqueront le développement du roman au XIXe siècle. Sur un ton agréable et à l’aide de micro-narrations montrant la vie quotidienne, les auteures et auteurs des périodiques disséminent les nouvelles normes sociales des Lumières auprès de la bourgeoisie émergente. Dans cet article, nous allons donc d’abord traiter brièvement des caractéristiques des spectateurs. Ensuite, nous examinerons le cadre idéologique du discours sur l’identité nationale au XVIIIe siècle et la relation étroite entre l’historiographie et la narration. Enfin, nous verrons à quel moment historique et avec quels dispositifs discursifs l’identité nationale est traitée dans les spectateurs espagnols et francophones.
Protection of Quiescence and Longevity of IgG Memory B Cells by Mitochondrial Autophagy
Authors: Kodali Srikanth , Li Min , Budai Marietta M , Chen Min , Wang Jin 
Published: January 2022

Abstract
The development of long-lived immune memory cells against pathogens is critical for the success of vaccines to establish protection against future infections. However, the mechanisms governing the long-term survival of immune memory cells remain to be elucidated. In this article, we show that the maintenance mitochondrial homeostasis by autophagy is critical for restricting metabolic functions to protect IgG memory B cell survival. Knockout of mitochondrial autophagy genes, Nix and Bnip3, leads to mitochondrial accumulation and increases in oxidative phosphorylation and fatty acid synthesis, resulting in the loss of IgG+ memory B cells in mice. Inhibiting fatty acid synthesis or silencing necroptosis gene Ripk3 rescued Nix−/−Bnip3−/− IgG memory B cells, indicating that mitochondrial autophagy is important for limiting metabolic functions to prevent cell death. Our results suggest a critical role for mitochondrial autophagy in the maintenance of immunological memory by protecting the metabolic quiescence and longevity of memory B cells.
Asymptotic growth of Mordell–Weil ranks of elliptic curves in noncommutative towers
Authors: Ray Anwesh 
Published: January 2022

AbstractLet E be an elliptic curve defined over a number field F with good ordinary reduction at all primes above p, and let
$F_\infty $
be a finitely ramified uniform pro-p extension of F containing the cyclotomic
$\mathbb {Z}_p$
-extension
$F_{\operatorname {cyc}}$
. Set
$F^{(n)}$
be the nth layer of the tower, and
$F^{(n)}_{\operatorname {cyc}}$
the cyclotomic
$\mathbb {Z}_p$
-extension of
$F^{(n)}$
. We study the growth of the rank of
$E(F^{(n)})$
by analyzing the growth of the
$\lambda $
-invariant of the Selmer group over
$F^{(n)}_{ \operatorname {cyc}}$
as
$n\rightarrow \infty $
. This method has its origins in work of A. Cuoco, who studied
$\mathbb {Z}_p^2$
-extensions. Refined estimates for growth are proved that are close to conjectured estimates. The results are illustrated in special cases.
Torsion properties of modified diagonal classes on triple products of modular curves
Authors: Lilienfeldt David T.-B. G. 
Published: January 2022

AbstractConsider three normalized cuspidal eigenforms of weight
$2$
and prime level p. Under the assumption that the global root number of the associated triple product L-function is
$+1$
, we prove that the complex Abel–Jacobi image of the modified diagonal cycle of Gross–Kudla–Schoen on the triple product of the modular curve
$X_0(p)$
is torsion in the corresponding Hecke isotypic component of the Griffiths intermediate Jacobian. The same result holds with the complex Abel–Jacobi map replaced by its étale counterpart. As an application, we deduce torsion properties of Chow–Heegner points associated with modified diagonal cycles on elliptic curves of prime conductor with split multiplicative reduction. The approach also works in the case of composite square-free level.
Experimental and theoretical investigations (FTIR, UV-VIS spectroscopy, HOMO-LUMO, NLO and MEP analysis) of aminothiophenol isomers
Authors: Kalaycı T. , K. Kınaytürk N. , Tunalı B. 
Published: January 2022

ABSTRACT. In this research, theoretical and experimental investigation was performed on the structural and spectral data of aminothiophenol isomers. The theoretical electronic structure analyses were performed by density functional theory at the B3LYP level with the LanL2DZ basis set in the gas phase of the isolated compounds at the ground state. Potential energy distribution analysis was performed to determine the assignments of the vibration bands. Experimental and theoretical spectroscopic data were compared. Energy gap, ionization potential, electron affinity, and electronegativity were obtained through frontier molecular orbitals.

KEY WORDS: Aminothiophenols, Density functional theory, Polarizability, Vibrational assignments, Molecular electrostatic potential surface

Bull. Chem. Soc. Ethiop. 2021, 35(3), 601-614.
DOI: https://dx.doi.org/10.4314/bcse.v35i3.11