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The X-ray-faint Emission of the Supermassive Nuclear Black Hole of IC1459

G. Fabbiano·M. Elvis·S. Markoff·A. Siemiginowska·S. Pellegrini·A. Zezas·F. Nicastro·G. Trinchieri·J. McDowell
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Abstract

Chandra observations of the supermassive black hole in the nucleus of IC1459 show a weak [L_X=8x10(40)erg s(-1), 0.3-8keV], unabsorbed nuclear X-ray source, with a slope Gamma=1.88+/-0.09, and no strong Fe-K line at 6.4keV (EW$<382 eV). This describes a normal AGN X-ray spectrum, but lies at 3x10(-7) below the Eddington limit. The SED of the IC1459 nucleus is extremely radio loud compared to normal radio-loud quasars. The nucleus is surrounded by hot ISM (kT~0.5-0.6 keV) with an average density of 0.3cm(-3), within the central ~180 pc radius, which is comparable to the gravitational capture radius, r_A~140 pc. We estimate that for a standard AGN efficiency of 10%, the Bondi accretion would correspond to a luminosity of ~6x10(44)erg s(-1), nearly four orders of magnitude higher than L_X. ADAF solutions can explain the X-ray spectrum, but not the high radio/X-ray ratio. A jet model fits the radio-100micron and X-ray spectra well. The total power in this jet is ~10% of L(Bondi), implying that accretion close to the Bondi rate is needed.

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G. Fabbiano, M. Elvis, S. Markoff, A. Siemiginowska, S. Pellegrini, A. Zezas, F. Nicastro, G. Trinchieri, J. McDowell. 2003-01-15. The X-ray-faint Emission of the Supermassive Nuclear Black Hole of IC1459. https://doi.org/10.1086/374040

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