Orbital elements and masses for the SMC X-1 / Sanduleak 160 binary system.
Abstract
The binary X-ray source SMC X-1 was observed with the SAS-3 satellite for approximately four days (February 26-29, 1976). Sufficient timing data were obtained on the 0.71 s X-ray pulsations to measure the Doppler velocity curve of the X-ray source and thereby derive orbital and stellar parameters for the system. The projected velocity of the X-ray star is 301.5 plus or minus 2.0 (1 sigma) km/s, and the corresponding mass function is 11.05 plus or minus 0.22 (1 sigma) solar masses. Combining the X-ray timing data with constraints imposed by the X-ray eclipse duration and the available optical data on Sk 160, a range of allowable values of not less than 1.1 and not greater than 4.0 solar masses for the mass of the X-ray star is obtained.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1976
- DOI:
- 10.1086/182306
- Bibcode:
- 1976ApJ...210L..71P
- Keywords:
-
- Eclipsing Binary Stars;
- Orbital Elements;
- Orbital Velocity;
- Stellar Mass;
- X Ray Sources;
- Magellanic Clouds;
- Sas;
- Velocity Distribution;
- X Ray Stars;
- Astrophysics