Shock oscillation model for quasi-periodic oscillations in stellar mass and supermassive black holes |
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| Authors: | T Okuda V Teresi D Molteni |
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| Institution: | Hakodate Campus, Hokkaido University of Education, Hachiman-cho 1-2, Hakodate 040-8567, Japan;Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienza, Palermo 90128, Italy |
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| Abstract: | We numerically examine centrifugally supported shock waves in 2D rotating accretion flows around a stellar mass (10 M⊙) and a supermassive (106 M⊙) black holes over a wide range of input accretion rates of  . The resultant 2D shocks are unstable with time and the luminosities show quasi-periodic oscillations (QPOs) with modulations of a factor of 2–3 and with periods of a tenth of a second to several hours, depending on the black hole masses. The shock oscillation model may explain the intermediate frequency QPOs with 1–10 Hz observed in the stellar mass black hole candidates and also suggest the existence of QPOs with the period of hours in active galactic nuclei. When the accretion rate  is low, the luminosity increases in proportion to the accretion rate. However, when  greatly exceeds the Eddington critical rate  , the luminosity is insensitive to the accretion rate and is kept constantly around ～3 L E . On the other hand, the mass-outflow rate  increases in proportion to  and it amounts to about a few per cent of the input mass-flow rate. |
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| Keywords: | accretion accretion discs black hole physics hydrodynamics radiation mechanism: thermal shock waves |
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