Kayhan Gultekin, Edward M. Cackett, Jon M. Miller, Tiziana Di Matteo, Sera Markoff, Douglas O. Richstone
We present Chandra observations of 12 galaxies that contain supermassive
black holes with dynamical mass measurements. Each galaxy was observed for 30
ksec and resulted in a total of 68 point source detections in the target
galaxies including supermassive black hole sources, ultraluminous X-ray
sources, 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 $\sim2$ with a slight trend towards
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 six 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 $1.0_{-0.3}^{+0.6} \times 10^{40}$ erg/s.
View original:
http://arxiv.org/abs/1202.3147
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