Active Galactic Nuclei Selected from GALEX Spectroscopy: The Ionizing
  Source Spectrum at z~1
  We use a complete sample of Lya emission-line selected AGNs obtained from
nine deep blank fields observed with the grism spectrographs on the Galaxy
Evolution Explorer (GALEX) satellite to measure the normalization and spectral
shape of the AGN contribution to the ionizing background (rest-frame
wavelengths 700-900 A) 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 A central
wavelength) channel. The area covered is 8.2 square degrees to a NUV magnitude
of 20.5 (AB) and 0.92 square degrees 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~1 in a fully self-consistent way.
