Is a black hole accretion disk in a self-organized critical state?

Abstract

view Abstract Citations (83) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Is a Black Hole Accretion Disk in a Self-organized Critical State? Mineshige, S. ; Takeuchi, M. ; Nishimori, H. Abstract In Mineshige et al. we have proposed that the inner portions of black hole accretion disks may be in a self-organized critical (SOC) state, thereby producing 1/f-like X-ray fluctuations (with f being a frequency) in spite of random mass input. The original model is modified so as to incorporate viscous diffusion process. Mass accretion, therefore, occurs either by an avalanche, which is triggered when the mass density of the disk exceeds some critical value, or by gradual gas diffusion. The model then produces 1/fbeta (with beta approximately 1.6) decline in the power spectrum, which is in good agreement with the observations that show a break to a steeper decline. We then discuss the observational features of the SOC state: (1) power spectra consisting of flat and power-law decline parts, (2) power-law-like peak-count distributions for individual shots and (3) non-random temporal distributions of very big shots. Detailed observational data analysis is urgently needed for confirmation. Publication: The Astrophysical Journal Pub Date: November 1994 DOI: 10.1086/187610 Bibcode: 1994ApJ...435L.125M Keywords: Accretion Disks; Black Holes (Astronomy); Galactic Nuclei; Seyfert Galaxies; Stellar Mass Accretion; X Ray Stars; Mathematical Models; Neutron Stars; Power Spectra; Satellite-Borne Instruments; Three Dimensional Motion; X Ray Spectra; Astrophysics; ACCRETION; ACCRETION DISKS; BLACK HOLE PHYSICS; GALAXIES: SEYFERT; X-RAYS: STARS full text sources ADS | data products SIMBAD (1)