Hydrogen and helium lines in theoretical models of Scorpius X-1 and Cygnus X-2.
Abstract
We calculate the equivalent widths and profiles for the first three Balmer lines and for He II A4786 in the spectra of atmospheres heated from above by X-rays. We use parameters appropriate to the systems Sco X- 1 and Cyg X-2. The crude features of the observed spectrum are reproduced, notably the fact that certain lines appear in emission and others in absorption. The finer details are shown also to be reproducible with reasonable values of the parameters. These results support the model in which the optical light from the systems is partly due to X-ray heating and reflection. Subject headings: line formation - stars: binaries - X-rays: sources
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1976
- DOI:
- 10.1086/154309
- Bibcode:
- 1976ApJ...205..545M
- Keywords:
-
- Binary Stars;
- H Lines;
- Helium;
- Stellar Models;
- X Ray Spectra;
- X Ray Stars;
- Astronomical Spectroscopy;
- Curve Fitting;
- Polynomials;
- X Ray Sources;
- Astrophysics