Component of energy flow from supercritical accretion disks around rotating stellar mass black holes

Aoto Utsumi, Ken Ohsuga, Hiroyuki R. Takahashi, Yuta Asahina

Submitted on 6 July 2022


By performing two-dimensional axisymmetric general relativistic radiation magnetohydrodynamics simulations with spin parameter a varying from -0.9 to 0.9, we investigate the dependence on the black hole spin of the energy flow from supercritical accretion disk around stellar mass black hole. It is found that optically and geometrically thick disks form near the equatorial plane, and a part of the disk matter is launched from the disk surface in all models. The gas ejection is mainly driven by the radiative force, but magnetic force cannot be neglected, when |a| is large. The energy outflow efficiency (total luminosity normalized by M˙inc2; M˙in and c are the mass accretion rate at the event horizon and the light speed) is larger for rotating black holes than for non-rotating black holes. This is 0.7% for a=0.7, 0.3% for a=0, and 5% for a=0.7 for M˙in100LEdd/c2 (LEdd is Eddington luminosity). Also, although the energy is mainly released by radiation when a0, the Poynting power increases with |a| and exceeds the radiative luminosity for models with a0.5 and a0.7. The more the black hole rotates, the larger the power ratio of the kinetic luminosity to the isotropic luminosity tends to be. This implies that objects with large (small) power ratio may have rapidly (slowly) rotating black holes. Among ultraluminous X-ray sources, IC342 X-1, is a candidate with a rapidly rotating black hole.


Comment: 14 pages, 8 figures, This paper has been accepted by APJ

Subject: Astrophysics - High Energy Astrophysical Phenomena