A Chandra survey of supermassive black holes with dynamical mass measurements.
GULTEKIN K., CACKETT E.M., MILLER J.M., DI MATTEO T., MARKOFF S. and RICHSTONE D.O.
Abstract (from CDS):
We present Chandra observations of 12 galaxies that contain supermassive black holes (SMBHs) with dynamical mass measurements. Each galaxy was observed for 30 ks and resulted in a total of 68 point-source detections in the target galaxies including SMBH sources, ultraluminous X-ray sources (ULXs), and extragalactic X-ray binaries. Based on our fits of the X-ray spectra, we report fluxes, luminosities, Eddington ratios, and slope of the power-law spectrum. Normalized to the Eddington luminosity, the 2-10 keV band X-ray luminosities of the SMBH sources range from 10–8 to 10–6, and the power-law slopes are centered at ∼2 with a slight trend toward steeper (softer) slopes at smaller Eddington fractions, implying a change in the physical processes responsible for their emission at low accretion rates. We find 20 ULX candidates, of which 6 are likely (>90% chance) to be true ULXs. The most promising ULX candidate has an isotropic luminosity in the 0.3-10 keV band of 1.0+0.6 _- 0.3_x1040 erg/s.
accretion, accretion disks - black hole physics - galaxies: general - galaxies: nuclei - X-rays: galaxies - X-rays: general