X-Ray Detection of an Obscured Active Galactic Nucleus in a z = 3.09 Radio-quiet Lyα Nebula

Abstract

We present evidence for a highly obscured X-ray source in one of two giantLy-alpha emission nebulae in the z=3.09 proto-cluster region SSA22. NeitherLy-alpha nebula is associated with significant radio emission. While one has asignificant submillimeter detection and is undetected in the X-ray, the otheris a factor of 2-10 times less submillimeter bright and appears to contain ahard-band X-ray source. We discuss our analysis and techniques for assessingthe X-ray properties of this source and suggest that we have detected anembedded AGN source in one of these nebulae which may be at least partiallyresponsible for exciting the Ly-alpha emission through a mechanism that isessentially decoupled from the radio, submillimeter, or optical luminosities.We also present an upper limit on the mean X-ray emission from 10 otherextended Ly-alpha objects in the SSA22 region.