Swift BAT Survey of AGNs

We present the results of the analysis of the first 9 months of data of the Swift BAT survey of AGNs in the 14-195 keV band. Using archival X-ray data or follow-up Swift XRT observations, we have identified 129 (103 AGNs) of 130 objects detected at [image] and with significance >4.8 capital sigma . One source remains unidentified. These same X-ray data have allowed measurement of the X-ray properties of the objects. We fit a power law to the [image] distribution, and find the slope to be [image]. Characterizing the differential luminosity function data as a broken power law, we find a break luminosity [image] (erg s super(-1)) = 43.85 +/- 0.26, a low-luminosity power law slope [image], and a high-luminosity power law slope [image], similar to the values that have been reported based on INTEGRAL data. We obtain a mean photon index 1.98 in the 14-195 keV band, with an rms spread of 0.27. Integration of our luminosity function gives a local volume density of AGNs above [image] erg s[image] of [image] Mpc[image], which is about 10% of the total luminous local galaxy density above [image]. We have obtained X-ray spectra from the literature and from Swift XRT follow-up observations. These show that the distribution of [image] is essentially flat from [image] to [image] cm[image], with 50% of the objects having column densities of less than [image] cm[image]. BAT Seyfert galaxies have a median redshift of 0.03, a maximum [image] luminosity of 45.1, and approximately half have [image].