The spin of a black hole is an important quantity to study, providing a window into the
processes by which a black hole was born and grew. Furthermore, spin can be a potent …

We review the properties and behavior of 20 X-ray binaries that contain a dynamically-
confirmed black hole, 17 of which are transient systems. During the past decade, many of …

We present the first sample of tidal disruption events (TDEs) discovered during the SRG all-
sky survey. These 13 events were selected among X-ray transients detected in the 0°< l< …

We develop a new spectral model for the broad-band spectral energy distribution (SED) of
active galactic nuclei (AGN). This includes an outer standard disc, an inner warm …

Abstract Narrow-line Seyfert 1 (NLS1) galaxies have low-mass black holes and mass
accretion rates close to (or exceeding) Eddington, so a standard blackbody accretion disc …

We review how the recent increase in X-ray and radio data from black hole and neutron star
binaries can be merged together with theoretical advances to give a coherent picture of the …

General relativity has passed all solar system experiments and neutron star based tests,
such as binary pulsar observations, with flying colors. A more exotic arena for testing …

Around a million quasars have been catalogued in the Universe by probing deeper and
using new methods for discovery. However, the hardest ones to find seem to be the rarest …

Astrophysical black hole candidates are thought to be the Kerr black holes of general
relativity, but there is not yet direct observational evidence that the spacetime geometry …

Relativistic reflection features are commonly observed in the X-ray spectra of accreting black
holes. In the presence of high quality data and with the correct astrophysical model, X-ray …