ACTIVE GALACTIC NUCLEI SELECTED FROM GALEX SPECTROSCOPY: THE IONIZING SOURCE SPECTRUM AT z {approx} 1 ,

Journal Article · Sun Aug 01 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/718/2/1235· OSTI ID:21455075

Barger, Amy J ^[1]

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1. Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States)

We use a complete sample of Ly{alpha}-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 A) at z {approx} 1. Our sample consists of 139 sources selected in the redshift range z = 0.65-1.25 in the near-ultraviolet (NUV; 2371 A central wavelength) channel. The area covered is 8.2 deg{sup 2} to a NUV magnitude of 20.5 (AB) and 0.92 deg{sup 2} 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 A 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 {approx} 1 in a fully self-consistent way.

• OSTI ID: 21455075
• Journal Information: Astrophysical Journal, Vol. 718, Issue 2; Other Information: DOI: 10.1088/0004-637X/718/2/1235; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COSMOLOGY
EMISSION
EMISSIVITY
FAR ULTRAVIOLET RADIATION
GALACTIC EVOLUTION
GALAXIES
GALAXY NUCLEI
LUMINOSITY
RED SHIFT
SPECTROSCOPY
WAVELENGTHS
ELECTROMAGNETIC RADIATION
EVOLUTION
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
SURFACE PROPERTIES
ULTRAVIOLET RADIATION