Black hole and neutron star X-ray binary systems routinely show quasi-periodic oscillations
(QPOs) in their X-ray flux. Despite being strong, easily measurable signals, their physical …

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 …

The geometry of the accretion flow around stellar-mass black holes can change on
timescales of days to months,–. When a black hole emerges from quiescence (that is, it 'turns …

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 …

The launch of NuSTAR and the increasing number of binary black hole (BBH) mergers
detected through gravitational wave observations have exponentially advanced our …

Current models of the spectrum of X-rays reflected from accretion discs around black holes
and other compact objects are commonly calculated assuming that the density of the disc …

We perform the first systematic search of all NICER archival observations of black hole (and
candidate) low-mass X-ray binaries for signatures of reverberation. Reverberation lags …

Aims. The only relativistic reflection model that implements a parameter relating the intensity
incident on an accretion disk to the observed intensity is relxill. The parameter used in …

Quasi-periodic oscillations (QPOs) are often present in the X-ray flux from accreting stellar-
mass black holes (BHs). If they are due to relativistic (Lense–Thirring) precession of an inner …

We obtained 16 VLT/X-shooter observations of GX 339− 4 in quiescence during the period
2016 May–September and detected absorption lines from the donor star in its NIR spectrum …