Observations of Cygnus X-3 by ANS.
Abstract
The hard X-ray experiment (1 - 28 keV) on ANS observed Cygnus X-3 in November 1974, and in May 1975. The average flux intensities for these time periods were found to be 22.4 + or - 0.5 cts/sec and 12.8 + or - 0.3 cts/sec (1.3 - 7.1 keV), the former being the highest average value ever observed. The spectrum studies show an excess in the flux above the fitted continuum which can be interpreted as a line emission of FeXXIV and/or FeXXV, at approximately 6.5 keV. The strength of this feature varied in phase with the 4.8 hr X-ray modulation, and remained at a constant relative intensity. The period of the X-ray modulation is refined to 0.1996813 + or - 0.0000006 day and obtained at a 2 sigma upper limit to a continuous change in the period of 50 to the minus 13th power/sec. This new limit places serious constraints on several models for this object.
- Publication:
-
NASA Special Publication
- Pub Date:
- 1976
- Bibcode:
- 1976NASSP.389..267P
- Keywords:
-
- Astronomical Netherlands Satellite;
- Cygnus Constellation;
- Satellite Observation;
- Binary Stars;
- Iron;
- Line Spectra;
- Spectrum Analysis;
- X Ray Sources;
- Astronomy