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 …

The quest for binary and dual supermassive black holes (SMBHs) at the dawn of the multi-
messenger era is compelling. Detecting dual active galactic nuclei (AGN)–active SMBHs at …

Context. Aims. Active galactic nuclei are known to have complex X-ray spectra that depend
on both the properties of the accreting super-massive black hole (eg mass, accretion rate) …

ABSTRACT The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on
2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in …

ABSTRACT X-ray reflection models are used to constrain the properties of the accretion
disk, such as the degree of ionization of the gas and the elemental abundances. In …

Luminous accreting stellar mass and supermassive black holes produce power–law
continuum X-ray emission from a compact central corona. Reverberation time lags occur …

We present a new and complete library of synthetic spectra for modeling the component of
emission that is reflected from an illuminated accretion disk. The spectra were computed …

Black hole X-ray binaries (BHXBs) are known to display five distinct spectral states. In order
of increasing luminosity these are the quiescent state, low state, intermediate state, high …

Abstract Using a Monte Carlo method, we derive approximations to Green's functions for the
Compton reflection of X-rays and γ-rays by cold electrons. In Compton reflection, X-rays and …

We study ł-ray observations of NGC 4151 by the Gamma Ray Observatory (GRO)/OSSE
contemporaneous with X-ray observations by ROSAT and Ginga in 1991 June and ASCA in …