X-ray polarization of the Cygnus sources
Multiple observations of Cygnus X-1, Cygnus X-2, and Cygnus X-3 were carried out with the Bragg crystal polarimeters aboard OSO 8. Of these sources, an unambiguous detection of the time-averaged polarization was obtained only for Cygnus X-1, which has a polarization of 2.4% +- 1.1% at 2.6 keV and 5.3% +- 2.5% at 5.2 keV. While statistically significant evidence for polarization of Cygnus X-2 of 4.9% +- 1.8% at 2.6 keV was obtained in a 1975 observation, this result was not confirmed in two later observations. For Cygnus X-3, modulation of the observed flux at twice the rotation frequency of the satellite, the signature of polarization, was also detected, but spurious modulation due to the presence of additional sources in the field of view cannot be ruled out.
- Research Organization:
- Columbia Astrophysics Laboratory, Departments of Astronomy and Physics, Columbia University
- OSTI ID:
- 5124427
- Journal Information:
- Astrophys. J.; (United States), Vol. 238:2
- Country of Publication:
- United States
- Language:
- English
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