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Low frequency radio monitoring of Cygnus X-1 and Cygnus X-3

M. Pandey·A. P. Rao·G. G. Pooley·P. Durouchoux·R. K. Manchanda·C. H. Ishwara-Chandra
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Abstract

We present results of monitoring observations of the micro-quasars CygnusX-1 and Cygnus X-3 at 0.61 and 1.28 GHz. The observations were performed with Giant Meter-wave Radio Telescope, GMRT, between 2003 June and 2005 January. Variable, unresolved sources were found in both cases. Cyg X-1 was detected in about half of the observations, with a median flux density about 7 mJy at each frequency. The results show clearly that there is a break in the spectrum above 1.28 GHz. The variations in Cyg X-1 may be due to refractive interstellar scintillation. Cyg X-3 was detected in each observation, and varied by a factor of 4. For this source, models of the scintillation suggest a very long timescale (of the order of 40 yr at 1.28 GHz), and therefore we believe that the variations are intrinsic to the source.

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M. Pandey, A. P. Rao, G. G. Pooley, P. Durouchoux, R. K. Manchanda, C. H. Ishwara-Chandra. 2005-09-19. Low frequency radio monitoring of Cygnus X-1 and Cygnus X-3. https://doi.org/10.1051/0004-6361%3A20053437

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