Outflow and hot dust emission in high redshift quasars
  Correlations of hot dust emission with outflow properties are investigated,
based on a large z~2 non-broad absorption lines quasar sample built from the
Wide-field Infrared Survey and the Sloan Digital Sky Survey data releases. We
use the near infrared slope and the infrared to UV luminosity ratio to indicate
the hot dust emission relative to the emission from the accretion disk. In our
luminous quasars, these hot dust emission indicators are almost independent of
the fundamental parameters, such as luminosity, Eddington ratio and black hole
mass, but moderately dependent on the blueshift and asymmetry index (BAI) and
full width at half-maximum (FWHM) of CIV lines. Interestingly, the latter two
correlations dramatically strengthen with increasing Eddington ratio. We
suggest that, in high Eddington ratio quasars, CIV regions are dominated by
outflows so the BAI and FWHM(CIV) can reliably reflect the general properties
and velocity of outflows, respectively. While in low Eddington ratio quasars,
CIV lines are primarily emitted by virialized gas so the BAI and FWHM(CIV)
become less sensitive to outflows. Therefore, the correlations for the highest
Eddington ratio quasars are more likely to represent the true dependence of hot
dust emission on outflows and the correlations for the entire sample are
significantly diluted by the low Eddington ratio quasars. Our results show that
an outflow with a large BAI or velocity can double the hot dust emission on
average. We suggest that outflows either contain hot dust in themselves or
interact with the dusty interstellar medium or torus.
