Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet...

The X-ray light curves of accreting black holes and neutron stars in binary systems show various types of quasi-periodic oscillations (QPOs), the origin of...

It has been suggested that the X-shaped morphology observed in some radio sources can reflect either a recent merger of two supermassive black holes (SMBHs) or...

Aims: We have estimated black hole masses (M BH) for 14 gravitationally lensed quasars using Balmer lines; we also provide estimates based on MgII and CIV...

We present new medium resolution, optical long-slit spectra of a sample of six ultraviolet (UV)/optical and 17 X-ray-selected tidal disruption event candidate...

We present new radio, optical, and X-ray observations of three ultraluminous X-ray sources (ULXs) that are associated with large-scale nebulae. We report the...

Sixteen years of observations of black hole transients with the Rossi X-ray Timing Explorer, complemented by other X-ray observatories and ground-based optical...

Context. Precise measurements of black hole masses are essential to understanding the coevolution of these sources and their host galaxies. Aims: We develop a...

We present preliminary results on the potential of HARMONI, the first light integral field spectrograph for the ELT, to explore the evolution of central super...