2002/11/23 by Sandip K. Chakrabarti, K. Acharyya, Chakrabarti, Sandip K. +4
Engineering · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #Heat Transfer Mechanisms #Sports Dynamics and Biomechanics #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0211516
Latex file (AASMS Style) Six eps figures, Submitted to Astrophysical Journals
arxiv created 2002/11/23 · openalex publication_date 2002/11/23 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present results of several numerical simulations of two dimensional axi-symmetric accretion flows around black holes using the Smoothed Particle Hydrodynamics (SPH). We consider both stellar black holes and as well as super-massive black holes. We assume bremsstrahlung to be the only source of cooling as it is simpler to implement in numerical simulations. We observe that due to both radial and vertical oscillation of shock waves in the accretion flow, the luminosity and average thermal energy content of the inner disk exhibit very interesting behaviors. When power density spectra are taken, quasi-periodic oscillations are seen at a few Hz and also occasionally at hundreds of Hz for stellar black holes. For super-massive black holes, the time-scale of the oscillations ranges from hours to weeks. The power density spectra have usual flat top behavior with average \it rms amplitude a few percent and a broken power-law behavior. The break frequency is generally found to be close to the QPO frequency as seen in the observed power spectra of black holes.