The study of ultraluminous X-ray sources (ULXs) has changed dramatically over the last
decade. In this review we first describe the most important observations of ULXs in various …

Active galactic nuclei (AGN) are energetic astrophysical sources powered by accretion onto
supermassive black holes in galaxies, and present unique observational signatures that …

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 …

We model the time variability of∼ 9000 spectroscopically confirmed quasars in SDSS Stripe
82 as a damped random walk (DRW). Using 2.7 million photometric measurements …

We review the properties of 40 X-ray binaries that contain either a confirmed black hole or a
black hole candidate. After discussing briefly the significance of these Galactic black holes to …

We study an empirical model for a unified description of the power spectra of accreting
neutron stars and black holes. This description is based on a superposition of multiple …

We show that the low-frequency quasi-periodic oscillations (QPOs) seen in the power-
density spectra of black hole binaries (and neutron stars) can be explained by the Lense …

We show that the rms–flux relation recently discovered in the X-ray light curves of active
galactic nuclei (AGN) and X-ray binaries (XRBs) implies that the light curves have a formally …

The fluctuating-accretion model of Lyubarskii and its extension by Kotov, Churazov &
Gilfanov seek to explain the spectral-timing properties of the X-ray variability of accreting …

It is shown that the energy dependence of the time-lags in Cygnus X-1 excludes any
significant contribution of the standard reflected component to the observed lags. The …