On the efficiency of jet production in radio galaxiesстатья из журнала
Аннотация: The mechanisms that produce and power relativistic jets are fundamental open questions in black hole (BH) astrophysics. In order to constrain these mechanisms, we analyze the energy efficiency of jet production 'eta' based on archival Chandra observations of 27 nearby, low-luminosity active galactic nuclei. We obtain 'eta' as the ratio of the jet power, inferred from the energetics of jet powered X-ray emitting cavities, to the BH mass accretion rate Mdot_BH. The standard assumption in estimating Mdot_BH is that all the gas from the Bondi radius 'r_B' makes it down to the BH. It is now clear, however, that only a small fraction of the gas reaches the hole. To account for this effect, we use the standard disk mass-loss scaling, Mdot(r) \propto (r/r_B)^s Mdot_Bondi. This leads to much lower values of Mdot_BH and higher values of 'eta' than in previous studies. If hot accretion flows are characterized by 0.50.6 are essentially ruled out, or there would be insufficient energy to power the jets. We discuss the implications of our results for the distribution of massive BH spins and the possible impact of a significant extra cold gas supply on our estimates.
Год издания: 2015
Авторы: Rodrigo Nemmen, Alexander Tchekhovskoy
Издательство: Oxford University Press
Источник: Monthly Notices of the Royal Astronomical Society
Ключевые слова: Astrophysical Phenomena and Observations, Astrophysics and Cosmic Phenomena, Pulsars and Gravitational Waves Research
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Monthly Notices of the Royal Astronomical Society (HTML)
arXiv (Cornell University) (PDF)
arXiv (Cornell University) (HTML)
arXiv (Cornell University) (PDF)
arXiv (Cornell University) (HTML)
arXiv (Cornell University) (PDF)
DataCite API (HTML)
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Том: 449
Выпуск: 1
Страницы: 316–327