The X-ray-faint emission of the supermassive nuclear black hole of IC 1459

Chandra observations of the supermassive black hole in the nucleus of IC 1459 show a weak (L-X = 8 x 10(40) ergs s(-1), 0.3-8 keV), unabsorbed nuclear X-ray source, with a slope Gamma = 1.88 +/- 0.09, and no strong Fe K line at 6.4 keV (EW < 382 eV). This describes a normal active galactic nucleus (AGN) X-ray spectrum but lies at 3 x 10(-7) below the Eddington limit. The spectral energy distribution of the IC 1459 nucleus is extremely radio-loud compared to normal radio-loud quasars. The nucleus is surrounded by a hot interstellar medium (kT similar to 0.5-0.6 keV) with an average density of 0.3 cm(-3), within the central similar to 180 pc radius, which is comparable to the gravitational capture radius, r(A) similar to 140 pc. We estimate that for a standard AGN efficiency of 10%, the Bondi accretion would correspond to a luminosity of similar to 6 x 10(44) ergs s(-1), nearly 4 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-100 mu m and X-ray spectra well. The total power in this jet is similar to 10% of L-Bondi, implying that accretion close to the Bondi rate is needed.