Microquasars: Summary and Outlook
Microquasars are compact objects (stellar-mass black holes and neutron stars) that mimic, on a smaller scale, many of the phenomena seen in quasars. Their discovery provided new insights into the physics of relativistic jets observed elsewhere in the Univ
- PDF / 671,861 Bytes
- 15 Pages / 439.37 x 666.142 pts Page_size
- 3 Downloads / 203 Views
Microquasars: Summary and Outlook I.F. Mirabel
Abstract Microquasars are compact objects (stellar-mass black holes and neutron stars) that mimic, on a smaller scale, many of the phenomena seen in quasars. Their discovery provided new insights into the physics of relativistic jets observed elsewhere in the Universe, and in particular, the accretion–jet coupling in black holes. Microquasars are opening new horizons for the understanding of ultraluminous X-ray sources observed in external galaxies, gamma-ray bursts of long duration, and the origin of stellar black holes and neutron stars. Microquasars are one of the best laboratories to probe General Relativity in the limit of the strongest gravitational fields, and as such, have become an area of topical interest for both high energy physics and astrophysics. At present, back hole astrophysics exhibits historical and epistemological similarities with the origins of stellar astrophysics in the last century.
1.1 Introduction Microquasars are binary stellar systems where the remnant of a star that has collapsed to form a dark and compact object (such as a neutron star or a black hole) is gravitationally linked to a star that still produces light, and around which it makes a closed orbital movement. In this cosmic dance of a dead star with a living one, the first sucks matter from the second, producing radiation and very high energetic particles (Fig. 1.1). These binary star systems in our galaxy are known under the name of “microquasars” because they are miniature versions of the quasars (“quasi-stellar radio source”), which are the nuclei of distant galaxies harboring a supermassive black hole, and are able to produce in a region as compact as the solar system, the luminosity of 100 galaxies like the Milky Way. Nowadays, the study of microquasars is one of the main scientific motivations of the space observatories that probe the X-ray and γ -ray Universe. I.F. Mirabel (B) Laboratoire AIM, Irfu/Service d’Astrophysique, Bat. 709, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France and Instituto de Astronom´ıa y F´ısica del Espacio (IAFE), CC 67, Suc. 28, 1428 Buenos Aires, Argentina, [email protected]
Mirabel, I.F.: Microquasars: Summary and Outlook. Lect. Notes Phys. 794, 1–15 (2010) c Springer-Verlag Berlin Heidelberg 2010 DOI 10.1007/978-3-540-76937-8 1
2
I.F. Mirabel
Fig. 1.1 In our galaxy there exist binary stellar systems where an ordinary star gravitates around a black hole that sucks the outer layers of the star’s atmosphere. When falling out to the dense star, the matter warms and emits huge amounts of energy as X-rays and γ -rays. The accretion disk that emits this radiation also produces relativistic plasma jets all along the axis of rotation of the black hole. The physical mechanisms of accretion and ejection of matter are similar to those found in quasars, but in million times smaller scales. Those miniature versions of quasars are known under the name of “microquasars”
Despite the differences in the involved masses and in the time and length scales,
Data Loading...
