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Clues from microquasars to the origin of radio-loudness of quasars

Carlo Nipoti·Katherine M. Blundell·James Binney
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Abstract

We analysed the long-term variability of four microquasars (GRS 1915+105, Cyg X-1, Cyg X-3, and Sco X-1) in radio and X rays. The results of our analysis indicate the existence of two distinct modes of energy output, which we refer to as the `coupled' mode and the `flaring' mode. The coupled mode is responsible for mildly fluctuating, flat-spectrum radio emission, coupled with the X-ray emission; the flaring mode produces powerful, steep-spectrum radio flares, with no significant counterpart in X rays. We find that the fraction of time spent by a typical microquasar in the flaring mode is similar to the fraction of quasars that are radio-loud. This is consistent with the hypothesis that radio-loudness of quasars is a function of the epoch at which the source is observed.

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Carlo Nipoti, Katherine M. Blundell, James Binney. 2006-11-06. Clues from microquasars to the origin of radio-loudness of quasars. https://arxiv.org/abs/astro-ph/0611166

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