We present spectroscopic observations of six high redshift (z(em) > 2) quasars, which have been selected for their Lyman alpha (Ly alpha) emission region being only partially covered by a strong proximate (z(abs) similar ...

In large optical surveys at high redshifts (z > 2), the C IV λ1549 broad emission line is the most practical alternative to estimate the mass (MBH) of active supermassive black holes. However, mass determinations obtained ...

Over the past 15 yr, examples of exotic radio-quiet quasars with intrinsically weak or absent broad emission line regions (BELRs) have emerged from large-scale spectroscopic sky surveys. Here, we present spectroscopy ...

We present Gemini-North K-band spectra of two representative members of the class of high-redshift quasars with exceptionally weak rest-frame ultraviolet emission lines (WLQs), SDSS J114153.34+021924.3 at z = 3.55 and SDSS ...

We investigate the strength of ultraviolet Fe ii emission in fainter quasars compared with brighter quasars for 1.0 a parts per thousand currency sign z a parts per thousand currency sign 1.8, using the Sloan Digital Sky ...

We present Reverberation Mapping results after monitoring a sample of 17 high-z, high-luminosity quasars for more than 10 years using photometric and spectroscopic capabilities. Continuum and line emission flux variability ...

We present reverberation mapping (RM) results for 17 high-redshift, high-luminosity quasars with good-quality R-band and emission-line light curves. We are able to measure statistically significant lags for Lyα (11 objects), ...