Astronomy Reports最新文献_第10页

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

引用次数: 0

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

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":"67 12","pages":"1355 - 1380"},"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

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

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923130115

S. A. Yazev

引用次数: 0

Analysis of the Effect of Earth’s Equatorial Ellipticity on the Existence and Stability of the Lagrangian Points in the Earth–Moon–Sun System 地球赤道椭圆度对地月日系统中拉格朗日点的存在和稳定性的影响分析

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923340036

Mukesh Kumar, Sushil Yadav

引用次数: 0

A Cross-Cut of the Sun 太阳的横切面

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923130085

S. A. Yazev

引用次数: 0

Sunspots, Solar Flares, and Coronal Partings 太阳黑子、太阳耀斑和日冕碎裂

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923130097

S. A. Yazev

引用次数: 0

Luminosity Outbursts in Interacting Protoplanetary Systems 相互作用原行星系统中的光度爆发

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923120107

A. M. Skliarevskii, E. I. Vorobyov

{"title":"Luminosity Outbursts in Interacting Protoplanetary Systems","authors":"A. M. Skliarevskii, E. I. Vorobyov","doi":"10.1134/S1063772923120107","DOIUrl":"10.1134/S1063772923120107","url":null,"abstract":"FU Orionis type objects (fuors) are characterized by rapid (tens to hundreds years) episodic outbursts, during which the luminosity increases by orders of magnitude. One of the possible causes of such events is a close encounter between stars and protoplanetary disks. Numerical simulations show that the fuor-like outburst ignition requires a very close encounter ranging from a few to a few tens of astronomical units. In contrast, the observed stellar objects in fuor binaries are usually hundreds of astronomical units apart. Simple mathematical estimates show that if such a close approach took place, the binary stellar components would have an unrealistic relative velocity, at least an order of magnitude greater than the observed velocity dispersion in young stellar clusters. Thus, the bursts are either triggered with a certain delay after passage of the periastron or their ignition does not necessary require a close encounter and hence the outburst is not caused by the primordial gravitational perturbation of the protoplanetary disk. In this work, an encounter of a star surrounded by a protoplanetary disk with a diskless external stellar object was modeled using numerical hydrodynamics simulations. We showed that even fly-bys with a relatively large periastron (at least 500 AU) can result in fuor-like outbursts. Moreover, the delay between the periastron passage and the burst ignition can reach several kyr. It was shown for the first time by means of numerical modeling that the perturbation of the disk caused by the external object can trigger a cascade process, which includes the development of the thermal instability in the innermost disk followed by the magneto-rotational instability ignition. Because of the sequential development of these instabilities, the rapid increase in the accretion rate occurs, resulting in the luminosity increase by more than two orders of magnitude.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"67 12","pages":"1401 - 1417"},"PeriodicalIF":1.1,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140884828","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

Polarized Light from Accreting Low Mass X-Ray Binaries 来自吸积低质量 X 射线双星的偏振光

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923140044

F. Capitanio, A. Gnarini, S. Fabiani, F. Ursini, R. Farinelli, M. Cocchi, N. Rodriguez Cavero, L. Marra

引用次数: 0

The Transformation of the Rotational Energy of an Accreting Kerr Black Hole 增殖克尔黑洞旋转能量的转变

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923140202

Shu-Rui Zhang

{"title":"The Transformation of the Rotational Energy of an Accreting Kerr Black Hole","authors":"Shu-Rui Zhang","doi":"10.1134/S1063772923140202","DOIUrl":"10.1134/S1063772923140202","url":null,"abstract":"Accretion of matter onto black holes (BHs) is a prevalent phenomenon in the cosmos, resulting in consequential changes to both the mass and irreducible mass of the BH. These alterations significantly impact the rotational energy reservoir harbored within. This study investigates the relationship between the increase in a BH’s irreducible mass and the augmentation of its total mass due to the infall of matter (test particles) from the innermost stable circular orbit (ISCO) of a Kerr BH. Interestingly, the ratio of total mass growth to irreducible mass growth proves to be a non-monotonic function concerning the dimensionless spin parameter. It initially rises with spin, culminating near an extreme BH ((hat {a} simeq 0.998)), before declining. At the extreme BH position, the ratio is (frac{{dM}}{{d{{M}_{{{text{irr}}}}}}} = sqrt 2 ), indicating that accretion along the ISCO leads to the ultimate stabilization of the BH as an extreme one. Conversely, massless particles falling along unstable circular orbits exhibit a continuous increasing ratio of total mass growth to irreducible mass growth with respect to the dimensionless spin parameter.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"67 2 supplement","pages":"S97 - S101"},"PeriodicalIF":1.1,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885127","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