1 research outputs found
The donor star of the X-ray pulsar X1908+075
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: = , kK, and = . 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 0.50 kpc
than the previously reported value.Comment: Accepted for publication in Section 7. Stellar structure and
evolution of Astronomy and Astrophysics. The official date of acceptance is
21/04/201