We have obtained spectropolarimetric observations of the four images of the gravitationally lensed broad absorption line quasar H1413+117. The polarization of the microlensed image D is significantly different, both in the ...

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 ...

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), ...

We study the compatibility of large quasar groups with the concordance cosmological model. Large quasar groups are very large spatial associations of quasars in the cosmic web, with sizes of 50-250 h(-1) Mpc. In particular, ...

The classification and identification of quasars is fundamental to many astronomical research areas. Given the large volume of photometric survey data available in the near future, automated methods for doing so are ...

The classification and identification of quasars is fundamental to many astronomical research areas. Given the large volume of photometric survey data available in the near future, automated methods for doing so are required. ...