Cambridge University Press (CUP), Proceedings of the International Astronomical Union, S267(5), p. 269-269, 2009
DOI: 10.1017/s1743921310006460
Full text: Unavailable
Our research addresses the observed evolution of MBH and L/LEdd of type 1 radio-quiet AGNs. Measurements of MBH and L/LEdd in a sample of sources at z<0.75 using the “Hβ method” (Netzer & Trakkhtenbrot 2007) as well as new measurements of these properties at 0.75<z<2 using the “Mg ii λ2798 method”) show significant evolution of L/LEdd for any value of MBH up to z = 2 (see Figure 1). In a dedicated near-IR project we obtained the most reliable sample of MBH and L/LEdd estimates for z ~ 2.3 and z ~ 3.4 AGN (Netzer et al. 2007; Shemmer et al. 2004); the distribution of L/LEdd is very broad (Figure 1) and ~ 1/2 of the sources have L/LEdd<0.2, implying tgrowth>tuniverse and hence an earlier epoch of fast growth. Our on-going Gemini–VLT campaign focuses on z ~ 4.8 sources, with the Mg ii line observed in the H-band (Figure 2). The analysis of ~ 1/3 of the spectra uncovers, again, a broad distribution of L/LEdd, with several sources having L/LEdd ≫ 1, suggesting an early episode of fast BH growth.