TY - JOUR
T1 - High-redshift sdss quasars with weak emission lines
AU - Diamond-Stanic, Aleksandar M.
AU - Fan, Xiaohui
AU - Brandt, W. N.
AU - Shemmer, Ohad
AU - Strauss, Michael A.
AU - Anderson, Scott F.
AU - Carilli, Christopher L.
AU - Gibson, Robert R.
AU - Jiang, Linhua
AU - Kim, J. Serena
AU - Richards, Gordon T.
AU - Schmidt, Gary D.
AU - Schneider, Donald P.
AU - Shen, Yue
AU - Smith, Paul S.
AU - Vestergaard, Marianne
AU - Young, Jason E.
PY - 2009
Y1 - 2009
N2 - We identify a sample of 74 high-redshift quasars (z > 3) with weak emission lines from the Fifth Data Release of the Sloan Digital Sky Survey and present infrared, optical, and radio observations of a subsample of four objects at z > 4. These weak emission-line quasars (WLQs) constitute a prominent tail of the Lyα + N v equivalent width distribution, and we compare them to quasars with more typical emission-line properties and to low-redshift active galactic nuclei with weak/absent emission lines, namely BL Lac objects. We find that WLQs exhibit hot (T 1000K) thermal dust emission and have rest-frame 0.1-5 μm spectral energy distributions that are quite similar to those of normal quasars. The variability, polarization, and radio properties of WLQs are also different from those of BL Lacs, making continuum boosting by a relativistic jet an unlikely physical interpretation. The most probable scenario for WLQs involves broad-line region properties that are physically distinct from those of normal quasars.
AB - We identify a sample of 74 high-redshift quasars (z > 3) with weak emission lines from the Fifth Data Release of the Sloan Digital Sky Survey and present infrared, optical, and radio observations of a subsample of four objects at z > 4. These weak emission-line quasars (WLQs) constitute a prominent tail of the Lyα + N v equivalent width distribution, and we compare them to quasars with more typical emission-line properties and to low-redshift active galactic nuclei with weak/absent emission lines, namely BL Lac objects. We find that WLQs exhibit hot (T 1000K) thermal dust emission and have rest-frame 0.1-5 μm spectral energy distributions that are quite similar to those of normal quasars. The variability, polarization, and radio properties of WLQs are also different from those of BL Lacs, making continuum boosting by a relativistic jet an unlikely physical interpretation. The most probable scenario for WLQs involves broad-line region properties that are physically distinct from those of normal quasars.
KW - Quasars: emission lines
KW - Quasars: general
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U2 - 10.1088/0004-637X/699/1/782
DO - 10.1088/0004-637X/699/1/782
M3 - Article
AN - SCOPUS:68049144429
SN - 0004-637X
VL - 699
SP - 782
EP - 799
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
ER -