Observations of Hercules X-1 with SAS-3 during 1975 July.
Abstract
X-ray pulsations from Her X-1 with energies between 0.1 and 30 keV were observed for four days with the SAS-3 satellite, during the 1975 July-August ON state of the source. The existence of a strong flux between 0.1 and 0.4 keV, with pulsations that are out of phase with those above 1 keV, is confirmed. A pulsed flux in the 19-30 keV band was discovered. The average fractional rate of change in pulse period between 1972 and 1975 was about 3 x 10 to the -6th/yr, and the absolute value of the average fractional rate of change in orbital period during the same interval was not greater than 5 x 10 to the -7th/yr
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1977
- DOI:
- 10.1086/155316
- Bibcode:
- 1977ApJ...214..874J
- Keywords:
-
- Eclipsing Binary Stars;
- Electromagnetic Pulses;
- Satellite-Borne Instruments;
- X Ray Sources;
- Doppler Effect;
- Phase Shift;
- Time Dependence;
- Astrophysics