TY - JOUR

T1 - Analysis of the X-ray emission from OB stars III

T2 - low-resolution spectra of OB stars

AU - Ryspaeva, Elizaveta

AU - Kholtygin, Alexander

N1 - Publisher Copyright: © 2020 National Astronomical Observatories, CAS and IOP Publishing Ltd.. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/7

Y1 - 2020/7

N2 - 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-resolutionX-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 L X weakly depend on the stellar magnetic field. At the same time, L X ∝ 0.5 and, where is the mass loss rate and E kin 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.

AB - 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-resolutionX-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 L X weakly depend on the stellar magnetic field. At the same time, L X ∝ 0.5 and, where is the mass loss rate and E kin 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.

KW - stars: early-type

KW - stars: spectra: X-Ray

KW - DRIVEN STELLAR WINDS

KW - DYNAMICAL SIMULATIONS

KW - MAGNETIC-FIELD

KW - MASS-LOSS

KW - MULTIWAVELENGTH

KW - VARIABILITY

KW - ABSORPTION

KW - ROTATION

KW - SHOCKS

KW - GALAXY

UR - http://www.scopus.com/inward/record.url?scp=85090388502&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/9299138e-08db-33c6-9672-ee023cd94756/

U2 - 10.1088/1674-4527/20/7/108

DO - 10.1088/1674-4527/20/7/108

M3 - Article

AN - SCOPUS:85090388502

VL - 20

JO - Research in Astronomy and Astrophysics

JF - Research in Astronomy and Astrophysics

SN - 1674-4527

IS - 7

M1 - 108

ER -