NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2018-12-11 T02:59:43 PST
Help | Comment | NED Home

For refcode 2004AJ....128.1483S:
Retrieve 525 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2004AJ....128.1483S An Optical Catalog of the Chandra Large Area Synoptic X-Ray Survey Sources A. T. Steffen, A. J. Barger, P. Capak, L. L. Cowie, R. F. Mushotzky, and Y. Yang Abstract. We present photometric and spectroscopic observations of the X-ray sources detected in the wide-area, moderately deep Chandra Large Area Synoptic X-ray Survey (CLASXS) of the Lockman Hole-Northwest field. We have B, V, R, I, and z' photometry for 521 (99%) of the 525 sources in the X-ray catalog and spectroscopic redshifts for 271 (52%), including 20 stars. We do not find evidence for redshift groupings of the X-ray sources, like those found in the Chandra Deep Field surveys, because of the larger solid angle covered by this survey. We separate the X-ray sources by optical spectral type and examine the colors, apparent and absolute magnitudes, and redshift distributions for the broad-line and non - broad-line active galactic nuclei. Combining our wide-area survey with other Chandra and XMM-Newton hard X-ray surveys, we find a definite lack of luminous, high accretion rate sources at z<1, consistent with previous observations that showed that supermassive black hole growth is dominated at low redshifts by sources with low accretion rates. Keywords: X-Rays: Galaxies, X-Rays: General
Retrieve 525 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home