The donor star of the X-ray pulsar X1908+075

Abstract

High-mass X-ray binaries (HMXBs) consist of a massive donor star and a compact object. While several of those systems have been well studied in X-rays, little is known for most of the donor stars as they are often heavily obscured in the optical and ultraviolet regime. There is an opportunity to observe them at infrared wavelengths, however. The goal of this study is to obtain the stellar and wind parameters of the donor star in the X1908+075 high-mass X-ray binary system with a stellar atmosphere model to check whether previous studies from X-ray observations and spectral morphology lead to a sufficient description of the donor star. We obtained H- and K-Band spectra of X1908+075 and analysed them with the Potsdam Wolf-Rayet (PoWR) model atmosphere code. For the first time, we calculated a stellar atmosphere model for the donor star, whose main parameters are: $M_{\mathrm{spec}}$ = $15\pm 6$$M_{\odot }$, $T_{\ast }=23_{-3}^{+6},$kK, $\log g_{\mathrm{eff}}=3.0\pm 0.2$ and $\log L/L_{\odot }$ = $4.81\pm 0.25$. The obtained parameters point towards an early B-type (B0--B3) star, probably in a supergiant phase. Moreover we determined a more accurate distance to the system of 4.85 $\pm$ 0.50 kpc than the previously reported value.

Accepted for publication in Section 7. Stellar structure and evolution of Astronomy and Astrophysics. The official date of acceptance is 21/04/2015

References in corpus (12)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• Pre-Supernova Evolution of Massive Single and Binary Stars
• The Second-Generation Guide Star Catalog: Description and Properties
• The WFCAM Science Archive
• The UKIRT Wide Field Camera ZYJHK Photometric System: Calibration from 2MASS
• The Galactic WN stars: Spectral analyses with line-blanketed model atmospheres versus stellar evolution models with and without rotation
• The Galactic WC stars: Stellar parameters from spectral analyses indicate a new evolutionary sequence
• On the consistent treatment of the quasi-hydrostatic layers in hot star atmospheres
• Tracing the long bar with red-clump giants
• Neutron star masses from hydrodynamical effects in obscured sgHMXBs
• Optical/infrared observations unveiling the formation, nature and evolution of High-Mass X-ray Binaries
• Astrophysical parameters and orbital solution of the peculiar X-ray transient IGR J00370+6122

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• Investigating the superorbital modulations in 4U 1909+07, IGR J16418-4532 and IGR J16479-4514 with Swift XRT, BAT and NuSTAR observations
• Swift/XRT monitoring of the orbital and superorbital modulations in 4U 1909+07
• Low-frequency spectra of neutron star + OB supergiant binaries: Does wind density drive persistent and flaring modes of accretion?