Negative absorption near a magnetized black hole: black hole masers

• Published in: Astrophysics and space science Vol. 124; no. 1; pp. 137 - 157
• Main Authors: ALIEV, A. N, GAL'TSOV, D. V, PETUKHOV, V. I
• Format: Journal Article
• Language: English
• Published: Dordrecht Kluwer 01-07-1986
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; Fundamental aspects of astrophysics; Fundamental astronomy and astrophysics. Instrumentation, techniques, and astronomical observations; Relativity and gravitation; Kerr metric; Black hole; Cosmic maser; Energy extraction
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/BF00649756

The mechanism of the energy extraction from charged particles moving in the vicinity of black holes due to the negative absorption of electromagnetic waves is considered. It is shown that there exist a number of resonant frequencies for which the ring of particles circling in the equatorial plane of Kerr black holes amplifies the incident electromagnetic waves. The negative absorption coefficients are calculated both for non-relativistic and ultrarelativistic cases. (Author)