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To better understand the mechanism or mechanisms that lead to AGN activitytoday, we measure the X-ray AGN fraction in a new sample of nearby clusters andexamine how it varies with galaxy properties, projected cluster-centric radius,and cluster velocity dispersion. We present new wide-field Chandra X-rayObservatory observations of Abell 85, Abell 754 and the background clusterAbell 89B out to their virial radii. Out of seventeen X-ray sources associatedwith galaxies in these clusters, we classify seven as X-ray AGN with L_{X,B} >10^{41} erg/s. Only two of these would be classified as AGN based on theiroptical spectra. We combine these observations with archival data to create asample of X-ray AGN from six z < 0.08 clusters and find that 3.4+1.1/-0.8% ofM_R < -20 galaxies host X-ray AGN with L_{X,B} > 10^{41} erg/s. We find thatmore X-ray AGN are detected in more luminous galaxies and attribute this tolarger spheriods in more luminous galaxies and increased sensitivity to lowerEddington-rate accretion from black holes in those spheroids. At a given X-rayluminosity limit, more massive black holes can be accreting less efficiently,yet still be detected. If interactions between galaxies are the principaldrivers of AGN activity, then the AGN fraction should be higher in lowervelocity dispersion clusters and the outskirts of clusters. However, thetendency of the most massive and early-type galaxies to lie in the centers ofthe richest clusters could dilute such trends. While we find no variation inthe AGN fraction with projected cluster-centric radius, we do find that the AGNfraction increases significantly from 2.6+1.0/-0.8% in rich clusters to10.0+6.2/-4.3% in those with lower velocity dispersions.

Wide-Field Chandra X-Ray Observations of AGN in Abell 85 & Abell 754