{"title":"Gas-Dynamical Model of Accretion on a Neutron Star with Viscosity and the Influence of Large-Scale Vortices on the Transmission of Angular Momentum","authors":"A. G. Aksenov, V. M. Chechetkin","doi":"10.1134/S1063772924700422","DOIUrl":null,"url":null,"abstract":"<p>The work is devoted to the construction of a gas-dynamic model of the accretion disk around a neutron star (NS). The developed multidimensional code is used to study the stability of stationary axially symmetrical models by carry out of evolutionary calculations in 3D taking into account viscosity, as well as taking into account the diffusion of radiation in 2D. It is shown that an arbitrary stationary axially symmetrical disk with a monotonic decrease in density with a cylindrical radius transforms, due to viscosity, braking and spreading of matter along the NS, into a new quasi-stationary toroidal configuration. The stability study of the stationary toroidal configuration confirmed the formation of large-scale vortex structures at the initial periodic disturbance of angular velocity in azimuth, now taking into account the “turbulent” viscosity. It turned out that the presence of large-scale structures leads to an acceleration of braking, i.e., an effective increase in viscosity.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Astronomy Reports","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1134/S1063772924700422","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
The work is devoted to the construction of a gas-dynamic model of the accretion disk around a neutron star (NS). The developed multidimensional code is used to study the stability of stationary axially symmetrical models by carry out of evolutionary calculations in 3D taking into account viscosity, as well as taking into account the diffusion of radiation in 2D. It is shown that an arbitrary stationary axially symmetrical disk with a monotonic decrease in density with a cylindrical radius transforms, due to viscosity, braking and spreading of matter along the NS, into a new quasi-stationary toroidal configuration. The stability study of the stationary toroidal configuration confirmed the formation of large-scale vortex structures at the initial periodic disturbance of angular velocity in azimuth, now taking into account the “turbulent” viscosity. It turned out that the presence of large-scale structures leads to an acceleration of braking, i.e., an effective increase in viscosity.
期刊介绍:
Astronomy Reports is an international peer reviewed journal that publishes original papers on astronomical topics, including theoretical and observational astrophysics, physics of the Sun, planetary astrophysics, radio astronomy, stellar astronomy, celestial mechanics, and astronomy methods and instrumentation.