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T. Weinzirl (Drake), M.S. Brotherton (Wyoming), K. Nandra (Imperial College), I. Georgantopoulos (National Observatory of Athens), I. Papadakis (Crete)
SHEEP is the Search for the High-Energy Extragalactic Population, a survey of X-rays sources found in 5-10 keV band images from the ASCA satellite. Because hard X-rays are difficult to obscure, SHEEP provides a largely unbiased accounting of the AGN population. We have been identifying SHEEP using new high-resolution Chandra images, and following up with deep optical imaging from Greece and near-infrared imaging from Wyoming. Spectral classifications are obtained at NOAO 4-meter telescopes. Our initial work shows a wide variety of optical classes, ranging from QSOs to optically normal galaxies (despite their high X-ray luminosities). We have also identified several high-redshift quasar pairs, which is intriguing given the size of the sample. Completion of identifications and classifications will permit us to finally "count the SHEEP" and provide a better picture of the AGN population and the sources contributing to the X-ray background.
This work has been supported by NSF REU grant AST-0353760.
The author(s) of this abstract have provided an email address for comments about the abstract: tmw007@DRAKE.EDU
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.