Analysis of the X-ray emission from OB stars Ⅲ: low-resolution spectra of OB stars  

作　　者：Elizaveta Ryspaeva Alexander Kholtygin 

机构地区：[1] Crimean Astrophysical Observatory,Nauchny,Crimea 298409,Russia [2] Saint-Petersburg State University,Saint-Petersburg 198504,Russia [3] Institute of Astronomy,Russian Academy of Sciences,ul.Pyatniskaya 48,Moscow 119017,Russia

出　　处：《Research in Astronomy and Astrophysics》2020年第7期161-171,共11页天文和天体物理学研究（英文版）

基　　金：support from the Russian Science Foundation grant(No.18–12–00423)。

摘　　要：This paper is the third in our series of papers devoted to the investigation of X-ray emission from OB stars.In our two previous papers,we study the high-resolution X-ray spectra of 32 O stars and 25 B stars to investigate the correlations between the properties of X-ray emission and stellar parameters.We checked if the X-ray hardness and post-shock plasma temperature grow with increasing stellar magnetic field,mass loss rate and terminal wind velocity.Our previous analysis of high-resolution spectra showed that the correlations are weak or even absent.In the present paper,we analyzed low-resolution X-ray spectra,using model-independent X-ray hardness values for checking the above mentioned dependencies.We establish that X-ray luminosities LX weakly depend on the stellar magnetic field.At the same time,Lx ∝ M0.5 and LX ∝ Ekin0.5,where M is the mass loss rate and Ekin is the kinetic energy of the wind.The X-ray luminosities decrease with growing magnetic confinement parameter η.We also argue that there is an additional(probably non-thermal) component contributed to the stellar X-ray emission.

关 键 词：stars:early-type stars:spectra:X-Ray 

分 类 号：P15[天文地球—天文学]