1978/09/01 by R. H. Becker, J. L. Robinson-Saba, S. H. Pravdo +4 · 1 citation
Physics and Astronomy · Engineering · #Astrophysical Phenomena and Observations #Astronomical Observations and Instrumentation #Atomic and Molecular Physics
paper · doi:10.1086/182772
openalex publication_date 1978/09/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
The X-ray binary Cyg X-3 has been observed on three occasions during 1975 and 1976 by the GSFC Cosmic X-Ray Spectroscopy Experiment on OSO 8. The X-ray spectra from all three observations can be represented by power-law continua with strong iron line emission. Comparisons of spectra taken within the same observation at various phases of the 4.8 hour period reveal a relative excess of low-energy X-ray emission near zero phase (i.e., the minimum) of the 4.8 hour modulation. In addition, the centroid of the line emission is observed to vary in phase with the 4.8 hour cycle. The possibility of persistent thermal X-ray emission from material surrounding the binary system is introduced in an effort to account for the observed effects.