Astronomy Reports最新文献_第8页

Gnevyshev–Ohl Rule: Current Status 格涅维舍夫-奥赫尔规则：现状

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700069

Yu. A. Nagovitsyn, A. A. Osipova, V. G. Ivanov

引用次数: 0

Orbital Period Changes of the Eclipsing Binaries RW Cap, BG Peg, and CU Peg 食双星 RW Cap、BG Peg 和 CU Peg 的轨道周期变化

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700094

A. I. Khaliullina

引用次数: 0

Modeling of the Exoplanet HAT-P-11b Magnetosphere 系外行星 HAT-P-11b 磁层建模

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700045

E. S. Belenkaya, I. I. Alexeev, V. V. Kalegaev

引用次数: 0

MHD Modeling of the Molecular Filament Evolution 分子丝演变的 MHD 模型

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700070

I. M. Sultanov, S. A. Khaibrakhmanov

{"title":"MHD Modeling of the Molecular Filament Evolution","authors":"I. M. Sultanov, S. A. Khaibrakhmanov","doi":"10.1134/S1063772924700070","DOIUrl":"10.1134/S1063772924700070","url":null,"abstract":"We perform numerical magnetohydrodynamic (MHD) simulations of the gravitational collapse and fragmentation of a cylindrical molecular cloud with the help of the FLASH code. The cloud collapses rapidly along its radius without any signs of fragmentation in the simulations without magnetic field. The radial collapse of the cloud is stopped by the magnetic pressure gradient in the simulations with parallel magnetic field. Cores with high density form at the cloud’s ends during further evolution. The core densities are (n approx 1.7 times {{10}^{8}}) and (2 times {{10}^{7}}) cm–3 in the cases with initial magnetic field strengths (B = 1.9 times {{10}^{{ - 4}}}) and (6 times {{10}^{{ - 4}}}) G, respectively. The cores move toward the cloud’s center with supersonic speeds (left| {{{{v}}_{z}}} right| = 3.6) and (5.3) km/s. The sizes of the cores along the filaments radius and filament’s main axis are ({{d}_{r}} = 0.0075) pc and ({{d}_{z}} = 0.025) pc, ({{d}_{r}} = 0.03) pc and ({{d}_{z}} = 0.025) pc, respectively. The masses of the cores increase during the filament evolution and lie in range of ( approx {kern 1pt} (10{-} 20){kern 1pt} {{M}_{ odot }}). According to our results, the cores observed at the edges of molecular filaments can be a result of the filament evolution with parallel magnetic field.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Brightness of the Sky of the Caucasian Mountain Observatory of MSU in the Near Infrared MSU 高加索山天文台天空的近红外亮度

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-05-08 DOI: 10.1134/S1063772924700082

A. M. Tatarnikov, S. G. Zheltoukhov, G. E. Nikishev, A. N. Tarasenkov, A. V. Sharonova

{"title":"The Brightness of the Sky of the Caucasian Mountain Observatory of MSU in the Near Infrared","authors":"A. M. Tatarnikov, S. G. Zheltoukhov, G. E. Nikishev, A. N. Tarasenkov, A. V. Sharonova","doi":"10.1134/S1063772924700082","DOIUrl":"10.1134/S1063772924700082","url":null,"abstract":"The results of measurements of background brightness in the near-infrared range (J, H, K bands), carried out in 2016–2023 at the Caucasus Mountain Observatory of Moscow State University was analyzed. It is shown that the instrumental background associated with the thermal radiation of the telescope is noticeable only in the (K) band, and at operating temperatures its contribution mainly determines the level of the overall background in this band. The coefficients of a polynomial taking into account the contribution of instrumental and extra-atmospheric backgrounds are presented. It is shown that the brightness of the sky background does not depend on air temperature, but a weak dependence on the water vapor content is observed, close to that expected from model calculations: in the (J) and (H) bands, the background brightness decreases at a rate of ( approx {kern 1pt} 1% {text{/}}1) mm, and in the (K) band it grows at a rate of ( approx {kern 1pt} 2.5% {text{/}}1) mm. The maximum amplitude of background brightness variability on short time scales (( sim {kern 1pt} 30) min) has been estimated: ( approx {kern 1pt} 10)% in the (J) and (K) bands and ( approx {kern 1pt} 30)% in the (H) band. The maximum contribution of Moon’s radiation scattered in the atmosphere to the overall background level has been determined. It is shown that this contribution can be ignored at an angular distance from the Moon greater than ( sim {kern 1pt} 10^circ ) even during a full moon. The average background surface brightness mag/arcsec2 in the J, H, and (K) bands was calculated: ({{m}_{J}} = 15.7), ({{m}_{H}} = 13.9), and ({{m}_{K}} = 13.1).","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Physical Properties and Kinematics of Dense Cores Associated with Regions of Massive Star Formation from the Southern Sky 南天大规模恒星形成区相关致密内核的物理特性和运动学特征

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923120077

L. E. Pirogov, P. M. Zemlyanukha, E. M. Dombek, M. A. Voronkov

{"title":"Physical Properties and Kinematics of Dense Cores Associated with Regions of Massive Star Formation from the Southern Sky","authors":"L. E. Pirogov, P. M. Zemlyanukha, E. M. Dombek, M. A. Voronkov","doi":"10.1134/S1063772923120077","DOIUrl":"10.1134/S1063772923120077","url":null,"abstract":"The results of spectral observations in the ( sim {kern 1pt} 84{-} 92) GHz frequency range of six objects in the southern sky containing dense cores and associated with regions of formation of massive stars and star clusters are presented. The observations were carried out with the MOPRA-22m radio telescope. Within the framework of the local thermodynamic equilibrium (LTE) approximation, the column densities and abundances of the H13CN, H13CO+, HN13C, HC3N, c-C3H2, SiO, CH3C2H and CH3CN molecules were calculated. Estimates of kinetic temperatures (( sim 30{-} 50) K), sizes of emission regions (( sim 0.2{-} 3.1) pc) and virial masses (( sim 70{-} 4600{kern 1pt} {{M}_{ odot }})) were obtained. The linewidths in the three cores decrease with increasing distance from the center. In four cores, asymmetry in the profiles of the optically thick lines HCO+(1–0) and HCN(1–0) is observed, indicating the presence of systematic motions along the line of sight. In two cases, the asymmetry can be caused by contraction of gas. The model spectral maps of HCO+(1–0) and H13CO+(1–0), obtained within the framework of the non-LTE spherically symmetric model, were fitted into the observed ones. The radial profiles of density (( propto {kern 1pt} {{r}^{{ - 1.6}}})), turbulent velocity (( propto {kern 1pt} {{r}^{{ - 0.2}}})), and contraction velocity (( propto {kern 1pt} {{r}^{{0.5}}})) in the G268.42–0.85 core have been calculated. The contraction velocity profile differs from that expected both in the case of free fall of gas onto a protostar (({{r}^{{ - 0.5}}})), and in the case of global core collapse (contraction velocity does not depend on distance). A discussion of the obtained results is provided.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Perturbed R3BP with Logarithmic Potential 具有对数电位的扰动 R3BP

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923340012

Abdullah, S. K. Sahdev

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Constraining Supernova Ia Progenitors by Their Locations in Host Galactic Discs 通过Ia超新星原生体在寄主星系盘中的位置对其进行约束

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923140081

A. A. Hakobyan, A. G. Karapetyan, L. V. Barkhudaryan

引用次数: 0

Solar Flares and Their Terrestrial Manifestations 太阳耀斑及其地面表现