N. Terasawa et H. Nakamura, THE IONIZATION STRUCTURE OF CYGNUS-X-3 - A MASSIVE IRON-DEPLETED COMPANION, Monthly Notices of the Royal Astronomical Society, 265(1), 1993, pp. 1-3
We investigate the ionization structure of the stellar wind of the Cyg
nus X-3 binary, exposed to luminous X-ray emission from the compact ob
ject. Comparing the simulated X-ray spectra with the observed ones, we
find that the companion star is fairly massive (5 less than or simila
r to M less than or similar to 10 M.), and that iron in the stellar wi
nd is somewhat depleted, to 0.1-0.5 times the cosmic abundance. The ph
ase-to-phase change of the X-ray spectrum implies that the wind gas is
enriched in any one of C, N or O. These results strongly support the
recent infrared observation.