Mirabel 1998 银河系中的微类星体

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看到了视超光速运动  GRS1915+105

著名的图就是来自这篇文章

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Progress

Nature 392, 673-676 (16 April 1998) | doi:10.1038/33603

Microquasars in our Galaxy

I. F. Mirabel¹ & L. F. Rodríguez²

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Abstract

Microquasars are stellar-mass black holes in our Galaxy that mimic, on a smaller scale, many of the phenomena seen in quasars. Their discovery opens the way for a new understanding of the connection between the accretion of matter onto black holes and the origin of the relativistic jets observed in remote quasars.

Discovered more than 30 years ago, quasars remain some of the most mysterious objects in the Universe. It is widely believed that they are powered by black holes of several million solar masses or more that lie at the centres of remote galaxies. Their luminosities are much larger than ordinary galaxies like the Milky Way, yet originate from regions smaller than the size of the Solar System. Occasionally, quasars spout jets of gas that appear to move on the plane of the sky with velocities exceeding that of light (that is, with superluminal velocities). The extreme distance of quasars introduces many uncertainties into the interpretation of the source of energy and the nature of the ejecta that appear to be moving with superluminal speeds.

The recent finding in our own Galaxy of microquasars^{1, 2, 3, 4}, a class of objects that mimics — on scales millions of times smaller — the properties of quasars, has opened new perspectives for the astrophysics of black holes (seeFig. 1). These scaled-down versions of quasars are believed to be powered by spinning black holes⁵ but with masses of up to a few tens times that of the Sun. The word microquasar was chosen to suggest that the analogy with quasars is more than morphological, and that there is an underlying unity in the physics of accreting black holes over an enormous range of scales, from stellar-mass black holes in binary stellar systems, to supermassive black holes at the centre of distant galaxies. As the characteristic times in the flow of matter onto a black hole are proportional to its mass, variations with intervals of minutes in a microquasar correspond to analogous phenomena with durations of thousands of years in a quasar of 10⁹ solar masses, which is much longer than a human lifetime. Therefore, variations with minutes of duration in microquasars could be sampling phenomena that we have not been able to study in quasars.