| Type |
Journal Article |
| Names |
Amy J. Barger, Lennox L. Cowie |
| Publication |
The Astrophysical Journal |
| Volume |
718 |
| Issue |
2 |
| Pages |
1235-1242 |
| Date |
August 1, 2010 |
| Short Title |
Active Galactic Nuclei Selected from GALEX Spectroscopy |
| URL |
http://adsabs.harvard.edu/abs/2010ApJ...718.1235B |
| Library Catalog |
NASA ADS |
| Abstract |
We use a complete sample of Lyα-emission-line-selected active
galactic nuclei (AGNs) obtained from nine deep blank fields observed
with the grism spectrographs on the Galaxy Evolution Explorer (GALEX)
satellite to measure the normalization and the spectral shape of the AGN
contribution to the ionizing background (rest-frame wavelengths 700-900
Å) at z ~ 1. Our sample consists of 139 sources selected in the
redshift range z = 0.65-1.25 in the near-ultraviolet (NUV; 2371 Å
central wavelength) channel. The area covered is 8.2 deg2 to
a NUV magnitude of 20.5 (AB) and 0.92 deg2 at the faintest
magnitude limit of 21.8. The GALEX AGN luminosity function agrees well
with those obtained using optical and X-ray AGN samples, and the
measured redshift evolution of the ionizing volume emissivity is similar
to that previously obtained by measuring the GALEX far-ultraviolet (FUV;
1528 Å central wavelength) magnitudes of an X-ray-selected sample.
For the first time, we are able to construct the shape of the ionizing
background at z ~ 1 in a fully self-consistent way.
Based in part on data obtained from the Multimission Archive at the
Space Telescope Science Institute (STScI). STScI is operated by the
Association of Universities for Research in Astronomy, Inc., under NASA
contract NAS5-26555. Support for Multimission Archive at STScI (MAST)
for non-HST data is provided by the NASA Office of Space Science via
grant NAG5-7584 and by other grants and contracts.
Based in part on data obtained at the W. M. Keck Observatory, which is
operated as a scientific partnership among the California Institute of
Technology, the University of California, and NASA, and was made
possible by the generous financial support of the W. M. Keck Foundation. |
| Tags |
cosmology: observations, galaxies: active, galaxies: distances and redshifts, intergalactic medium |