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A.F. Ptak (CMU), L.C. Ho (CIW), E.D. Feigelson, R.M. Sambruna, L. Townsley, W.N. Brandt, G.P. Garmire (PSU), R.E. Griffiths (CMU), W.L.W. Sargent (CalTech), A.V. Filippenko (Berkley)
We report on the results of a volume-limited Chandra ACIS-S snapshot survey of nearby galaxies. The typical exposure time was several ks. The sample consists of low-luminosity Seyferts, LINERs, and LINER/H~II transition nuclei. Of the 24 galaxies observed to date, ~75% have been detected in the 0.5-8.0 keV bandpass. The detection rate is roughly independent of the optical spectral class. In many cases USNO sources were also detected, allowing the astrometry to be corrected to better than 1\prime \prime accuracy. In addition to the nuclear sources, we invariably find a number of compact sources, presumably X-ray binaries, distributed away from the nucleus. The sensitivity of the survey is ~LX ~ 1037-38 \ \rm ergs \ s-1, unless the column density is on the order of 1023 \ \rm cm-2 in which case the limiting luminosity is ~1039 \rm \ ergs \ s-1, or comparable to the least-luminous AGNs known. Most or all of our sample should have been observed by November 2000. The X-ray luminosity is correlated with H\alpha luminosity, although with significant scatter. This correlation extends the trend previously established for more powerful sources (based on ASCA data) down by a factor of ~100 in luminosity, and it is relatively free of selection biases given the completeness of our data.
This work is supported by NASA contract NAS8-38252.
The author(s) of this abstract have provided an email address for comments about the abstract: ptak@astro.phys.cmu.edu