We study the dependence of the number density and properties of quasars on the background galaxy density using the currently largest spectroscopic data sets of...

We tackle the long-standing question “what is the relevance of major mergers and interactions as triggering mechanisms for AGN activity?” We study a sample of...

OTELO is a survey of emission line objects that will be carried out using tunable filters with OSIRIS at the GTC. The survey will have a deep impact on...

Active galactic nuclei (AGNs) are known to exhibit optical/ultraviolet variability and most of them can be well modelled by the damped random walks. Physical...

Broad absorption lines (BALs) found in a significant fraction of quasar spectra identify high-velocity outflows that might be present in all quasars and could...

Context. Even the spectroscopic capabilities of today's ground and space-based observatories can not keep up with the enormous flow of detections (>105 deg-2)...

We present high-sensitivity eMERLIN radio images of the Seyfert galaxy NGC 4151 at 1.51 GHz. We compare the new eMERLIN images to those from archival MERLIN...

Infrared observations taken during the major outburst seen in 1993 show strong evidence of rapid variability in 3C 66A on a time scale of a few hours, with...