GALEX UV-bright high-redshift quasars Virtual Observatory Resource

Authors
  1. Worseck G.
  2. Prochaska J.X.
  3. Published by
    CDS
Abstract

We study the small population of high-redshift (z_em_>2.7) quasars detected by the Galaxy Evolution Explorer(GALEX), whose far-UV emission is not extinguished by intervening HI Lyman limit systems. We correlate almost all verified z_em_>2.7 quasars to the GALEX GR4 source catalog covering ~25000deg^2^, yielding 304 sources detected at signal-to-noise ratio (S/N)>3. However, ~50% of these are only detected in the GALEX NUV band, signaling the truncation of the FUV flux by low-redshift optically thick Lyman limit systems. We regard 52 quasars detected at S/N>3 to be most promising for Hubble Space Telescope follow-up, with an additional 114 quasars if we consider S/N>2 detections in the FUV. Combining the statistical properties of HI absorbers with the Sloan Digital Sky Survey (SDSS) quasar luminosity function, we predict a large all-sky population of ~200 quasars with z_em_>2.7 and i<~19 that should be detectable at the HeII edge at m_304_<21. However, SDSS provides just half of the NUV-bright quasars that should have been detected by SDSS and GALEX. With mock quasar photometry we revise the SDSS quasar selection function, finding that SDSS systematically misses quasars with blue u-g<~2 colors at 3<~z_em_<~3.5 due to overlap with the stellar locus in color space.

Keywords
  1. ultraviolet-photometry
  2. visible-astronomy
  3. sloan-photometry
  4. redshifted
  5. quasars
  6. surveys
Bibliographic source Bibcode
2011ApJ...728...23W
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/728/23
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJ/728/23
Document Object Identifer DOI
doi:10.26093/cds/vizier.17280023

Access

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https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/728/23
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/728/23
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/728/23
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https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/728/23/table3?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/728/23/table3?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/728/23/table3?
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/728/23/table4?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/728/23/table4?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/728/23/table4?

History

2012-10-16T15:43:53Z
Resource record created
2012-10-16T15:43:53Z
Created
2017-11-28T13:21:31Z
Updated

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr