The Covering Factor of Warm Dust in Weak Emission-Line Active Galactic
  Nuclei
  Weak emission-line active galactic nuclei (WLAGNs) are radio-quiet active
galactic nuclei (AGNs) that have nearly featureless optical spectra. We
investigate the ultraviolet to mid-infrared spectral energy distributions of 73
WLAGNs (0.4<z<3) and find that most of them are similar to normal AGNs. We also
calculate the covering factor of warm dust of these 73 WLAGNs. No significant
difference is indicated by a KS test between the covering factor of WLAGNs and
normal AGNs in the common range of bolometric luminosity. The implication for
several models of WLAGNs is discussed. The super-Eddington accretion is
unlikely the dominant reason for the featureless spectrum of a WLAGN. The
present results favor the evolution scenario, i.e., WLAGNs are in a special
stage of AGNs.
