Broad-line AGNs with Candidate Intermediate-mass Black holes in the   Sloan Digital Sky Survey
  We have conducted a systematic search of AGNs with IMBHs from the SDSS DR4. As results we found 245 candidates of broad-line AGN with M_{BH}<10^6 \Msun estimated from the luminosity and width of the broad Halpha component. Compared to the pioneer Greene & Ho (2004) sample of 19 IMBH AGNs, our sample has improved in covering a larger range of the Eddington ratio, as well as black hole mass and redshift, taking the advantage of our AGN-galaxy spectral decomposition algorithm. Among these, thirty-six have L_{bol}/L_{Edd} < 0.1, hinting that a significant fraction of IMBHs might exist with weak or no nuclear activity. 
Xiaobo Dong (1), Tinggui Wang (1), Weimin Yuan (2), Hongyan Zhou (1),   Hongguang Shan (2), Huiyuan Wang (1), Honglin Lu (1)...