English

The Mass of the Compact Object in the X-Ray Binary Her X-1/HZ Her

Solar and Stellar Astrophysics 2015-06-03 v1

Abstract

We have obtained the first estimates of the masses of the components of the Her X-1/HZ Her X-ray binary system taking into account non-LTE effects in the formation of the H_gamma absorption line: mx=1.8Msun and mv=2.5Msun. These mass estimates were made in a Roche model based on the observed radial-velocity curve of the optical star, HZ Her. The masses for the X-ray pulsar and optical star obtained for an LTE model lie are mx=0.85\pm0.15Msun and mv=1.87\pm0.13Msun. These mass estimates for the components of Her X-1/HZ Her derived from the radial-velocity curve should be considered tentative. Further mass estimates from high-precision observations of the orbital variability of the absorption profiles in a non-LTE model for the atmosphere of the optical component should be made.

Keywords

Cite

@article{arxiv.1201.5519,
  title  = {The Mass of the Compact Object in the X-Ray Binary Her X-1/HZ Her},
  author = {M. K. Abubekerov and E. A. Antokhina and A. M. Cherepashchuk and V. V. Shimanskii},
  journal= {arXiv preprint arXiv:1201.5519},
  year   = {2015}
}

Comments

20 pages, 4 tables, 8 figures