부산대학교 도서관

We present a search for nuclear X-ray emission in the brightest cluster galaxies (BCGs) of a sample of groups and clusters of galaxies extracted from the Chandra archive. The exquisite angular resolution of Chandra allows us to obtain robust photometry at the position of the BCG, and to firmly identify unresolved X-ray emission when present, thanks to an accurate characterization of the extended emission at the BCG position. We consider two redshift bins (0.2Comment: 59 pages, 14 figures; We note that unlike the final astro-ph version here, the published ApJ version has mistakenly a part of the Abstract missing (an Erratum is due to come out soon)