TY - JOUR

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

T2 - O stars

AU - Ryspaeva, Elizaveta

AU - Kholtygin, Alexander

PY - 2018/8/1

Y1 - 2018/8/1

N2 - We investigate the global properties of X-ray emission from O stars, analyzing the X-ray spectra of 32 O stars from archival data of the XMM-Newton space observatory. We examine two hypotheses about of the origin of X-ray emission from O stars. The first is a paradigm proposed by Pollock, that was revealed from an analysis of the ζ Ori X-ray observation. The second is the magnetically confined wind-shock (MCWS) model. For checking Pollock's hypothesis, we determine the distribution of the ratio of half width at half maximum (HWHM) to the wind terminal velocity for lines in spectra of all examined stars. In addition, we check three probable consequences from the MCWS model. We analyze if a correlation exists between the spectral hardness and such stellar parameters as the wind terminal velocity, stellar magnetic field and mass loss rate. The result showed that Pollock's hypothesis is not correct. We also established that not all consequences of the MCWS model considered by us are confirmed. In addition, our spectral analysis method indicated that O stars probably have clumped stellar winds with spherical clumps.

AB - We investigate the global properties of X-ray emission from O stars, analyzing the X-ray spectra of 32 O stars from archival data of the XMM-Newton space observatory. We examine two hypotheses about of the origin of X-ray emission from O stars. The first is a paradigm proposed by Pollock, that was revealed from an analysis of the ζ Ori X-ray observation. The second is the magnetically confined wind-shock (MCWS) model. For checking Pollock's hypothesis, we determine the distribution of the ratio of half width at half maximum (HWHM) to the wind terminal velocity for lines in spectra of all examined stars. In addition, we check three probable consequences from the MCWS model. We analyze if a correlation exists between the spectral hardness and such stellar parameters as the wind terminal velocity, stellar magnetic field and mass loss rate. The result showed that Pollock's hypothesis is not correct. We also established that not all consequences of the MCWS model considered by us are confirmed. In addition, our spectral analysis method indicated that O stars probably have clumped stellar winds with spherical clumps.

KW - stars: early-type

KW - stars: spectra: X-ray

KW - ZETA-ORIONIS

KW - SPECTROSCOPY

KW - FIELD

KW - STELLAR

KW - SPECTRAL VARIABILITY

KW - PARAMETERS

KW - MAGNETICALLY CONFINED WIND

KW - PARADIGM

UR - http://www.scopus.com/inward/record.url?scp=85051520575&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/analysis-xray-emission-ob-stars-o-stars

U2 - 10.1088/1674-4527/18/8/104

DO - 10.1088/1674-4527/18/8/104

M3 - Article

AN - SCOPUS:85051520575

VL - 18

JO - Research in Astronomy and Astrophysics

JF - Research in Astronomy and Astrophysics

SN - 1674-4527

IS - 8

M1 - 104

ER -