X-ray emission from hot accretion flows - 黑洞吸积与高能天体物理研究组

黑洞吸积与高能天体物理研究组

简介黑洞吸积与高能天体物理研究组由袁峰研究员领导，目前有三名副研究员，三名博士后，八名学生和一名实习生。

Abstract Radiatively inefficient, hot accretion flows are widely considered as a relevant accretion mode in low-luminosity AGNs. We study spectral formation in such flows using a refined model with a fully general relativistic description of both the radiative (leptonic and hadronic) and hydrodynamic processes, as well as with an exact treatment of global Comptonization. We find that the X-ray spectral index–Eddington ratio anticorrelation as well as the cut-off energy measured in the best-studied objects favor accretion flows with rather strong magnetic field and with a weak direct heating of electrons. Furthermore, they require a much stronger source of seed photons than considered in previous studies. The nonthermal synchrotron radiation of relativistic electrons seems to be the most likely process capable of providing a sufficient flux of seed photons. Hadronic processes, which should occur due to basic properties of hot flows, provide an attractive explanation for the origin of such electrons.