Candidate type II QSOs in SDSS III Virtual Observatory Resource

Authors
  1. Alexandroff R.
  2. Strauss M.A.
  3. Greene J.E.
  4. Zakamska N.L.
  5. Ross N.P.,Brandt W.N.
  6. Liu G.
  7. Smith P.S.
  8. Ge J.
  9. Hamann F.
  10. Myers A.D.,Petitjean P.
  11. Schneider D.P.
  12. Yesuf H.
  13. York D.G.
  14. Published by
    CDS
Abstract

At low redshifts, dust-obscured quasars often have strong yet narrow permitted lines in the rest-frame optical and ultraviolet, excited by the central active nucleus, earning the designation type II quasars. We present a sample of 145 candidate type II quasars at redshifts between 2 and 4.3, encompassing the epoch at which quasar activity peaked in the universe. These objects, selected from the quasar sample of the Baryon Oscillation Spectroscopic Survey of the Sloan Digital Sky Survey III, are characterized by weak continuum in the rest-frame ultraviolet (typical continuum magnitude of i~22) and strong lines of CIV and Ly{alpha}, with full width at half-maximum less than 2000km/s. The continuum magnitudes correspond to an absolute magnitude of -23 or brighter at redshift 3, too bright to be due exclusively to the host galaxies of these objects. Roughly one third of the objects are detected in the shorter wavelength bands of the Wide-Field Infrared Survey Explorer survey; the spectral energy distributions of these objects appear to be intermediate between classic type I and type II quasars seen at lower redshift. Five objects are detected at rest frame 6{mu}m by Spitzer, implying bolometric luminosities of several times 10^46^erg/s. We have obtained polarization measurements for two objects; they are roughly 3 percent polarized. We suggest that these objects are luminous quasars, with modest dust extinction (A_V_~0.5mag), whose ultraviolet continuum also includes a substantial scattering contribution. Alternatively, the line of sight to the central engines of these objects may be obscured by optically thick material whose covering fraction is less than unity.

Keywords
  1. quasars
  2. line-intensities
  3. infrared-photometry
Bibliographic source Bibcode
2013MNRAS.435.3306A
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/435/3306
IVOA Identifier IVOID
ivo://CDS.VizieR/J/MNRAS/435/3306
Document Object Identifer DOI
doi:10.26093/cds/vizier.74353306

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/435/3306
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/435/3306
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/435/3306
IVOA Table Access TAP
http://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
https://vizier.cds.unistra.fr/viz-bin/conesearch/0?
https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/435/3306/qso2?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/435/3306/qso2?

History

2014-11-12T11:45:30Z
Resource record created
2014-11-12T11:45:30Z
Created
2024-08-06T20:17:13Z
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