On the evolution of the cosmic supernova rates |
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| Authors: | Piero Madau Massimo Della Valle & Nino Panagia |
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| Institution: | Nuffield Radio Astronomy Laboratory, Jodrell Bank, Macclesfield, Cheshire SK11 9DL |
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| Abstract: | The Galactic radio-emitting X-ray binary Cygnus X-3 is known to be a source of large-scale radio jets associated with periods of intense radio flaring. These jets have been found to have an expansion velocity of ～0.3 c and are believed (on kinematic grounds) to lie close to the plane of the sky. We present new observations of Cygnus X-3 using the VLBA at 15 GHz. These observations, which included the detection of two small flares, show an additional kind of behaviour with apparent superluminal expansion along both major and minor axes. Evidence for superluminal activity has been found in a number of X-ray binary systems such as GRS 1915+105 and GRO J1655?40 with their superluminal radio jets. Apparently similar morphologies of the Galactic and extragalactic jet sources have led to the X-ray binaries being described as 'micro-quasars'. The superluminal expansion seen in our results appears to be different in nature from these other two sources, and a number of mechanisms are presented and discussed. |
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| Keywords: | accretion accretion discs binaries: close stars: individual: Cygnus X-3 radio continuum: stars |
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