Spherical Accretion in Nearby Weakly Active Galaxies

Abstract

We consider the sample of weakly active galaxies situated in 'Local Universe' collected in the paper of Pellegrini (2005) with inferred accretion efficiencies from $10^{-2}$ to $10^{-7}$. We apply a model of spherically symmetrical Bondi accretion for given parameters ($M_{BH}$,$T_{\infty }$,${\rho }_{\infty }$,) taken from observation. We calculate spectra emitted by the gas accreting onto its central objects using Monte Carlo method including synchrotron and bremsstrahlung photons as seed photons. We compare our results with observed nuclear X-ray luminosities $L_{X,nuc}$ (0.3-10 keV) of the sample. Model is also tested for different external medium parameters (${\rho }_{\infty }$ and $T_{\infty }$) and different free parameters of the model. Our model is able to explain most of the observed nuclear luminosities $L_X$ under an assumption that half of the compresion energy is transfered directly to the electrons.

19 pages, 11 figures, accepted to A&A

References in corpus (10)

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• Nuclear Accretion in Galaxies of the Local Universe: Clues from Chandra Observations
• Variable Linear Polarization from Sagittarius A*: Evidence for a Hot Turbulent Accretion Flow
• AGN feedback and gas mixing in the core of NGC 4636
• Chandra Observation of Diffuse Gas and LMXBs in the Elliptical Galaxy NGC 4649 (M60)
• Hot Gas Structure in the Elliptical Galaxy NGC 4472
• Chandra Observations of NGC 4438: An Environmentally Damaged Galaxy in the Virgo Cluster
• An XMM-Newton and Chandra investigation of the nuclear accretion in the Sombrero Galaxy (NGC4594)
• Chandra's Discovery of Activity in the Quiescent Nuclear Black Hole of NGC 821
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Cited by in corpus (10)

• A deep Chandra look at the low L_B elliptical NGC821: X-ray binaries, a galactic wind and emission at the nucleus
• A deep Chandra, VLA and Spitzer IRAC study of the very low luminosity nucleus of the elliptical NGC821
• Spherical accretion: Bondi, Michel and rotating black holes
• Accretion of Low Angular Momentum Material onto Black Holes: Radiation Properties of Axisymmetric MHD Flows
• Multi-phase environment of compact galactic nuclei: the role of the Nuclear Star Cluster
• What is the real accretion rate onto a black hole for low angular momentum accretion?
• Influence of flow thickness on general relativistic low angular momentum accretion around spinning black holes
• Effect of matter geometry on low angular momentum black hole accretion in the Kerr metric
• Low angular momentum flow model of Sgr A* activity
• Low angular momentum accretion flow model of Sgr A* activity