Philip Uttley

Accretion disc variability in the hard state of black hole X-ray binaries (2009)

Wilkinson, Tony, Uttley, Philip

XMM-Newton X-ray spectra of the hard state Black Hole X-Ray Binaries (BHXRBs) SWIFT J1753.5-0127 and GX 339-4 show evidence for accretion disc blackbody emission, in addition to hard power-laws. The...

Studying accreting black holes and neutron stars with time series:beyond the power spectrum (2007)

Vaughan, Simon, Uttley, Philip

Paper presented at Noise and Fluctuations in Photonics, Quantum Optics, and Communications Conference, Vv 6603, 7 June 2007. The authors web-site can also be accessed via...

A brief review of long-term X-ray and optical variability in radio-quiet AGN (2004)

Uttley, Philip, McHardy, Ian M.

Long-time-scale X-ray and optical variability is a key characteristic of AGN. Here, we summarise our current understanding of the X-ray and optical continuum variability of radio-quiet AGN and the...

SAX J1808.4−3658 and the origin of x-ray variability in x-ray binaries and active galactic nuclei (2004)

Uttley, Philip

The aperiodic x-ray variability in neutron star and black hole x-ray binaries (XRBs) and active galactic nuclei (AGN) shows a characteristic linear relationship between rms amplitude and flux,...

SAX J1808.4-3658 and the origin of X-ray variability in X-ray binaries and active galactic nuclei (2003)

Uttley, Philip

The aperiodic X-ray variability in neutron star and black hole X-ray binaries (XRBs), and active galactic nuclei (AGN) shows a characteristic linear relationship between rms amplitude and flux,...

The nature of X-ray spectral variability in Seyfert Galaxies (2003)

Taylor, Richard D., Uttley, Philip, McHardy, Ian M.

We use a model-independent technique to investigate the nature of the 2-15 keV X-ray spectral variability in four Seyfert galaxies and distinguish between spectral pivoting and the two-component...

Correlated long-term optical and x-ray variations in NGC 5548 (2003)

Uttley, Philip, Edelson, Rick, McHardy, Ian M., Peterson, Bradley M., Markowitz, Alex

We combine the long-term optical light curve of the Seyfert 1 galaxy NGC 5548 with the X-ray light curve measured by the Rossi X-Ray Timing Explorer over 6 years, to determine the relationship...

The flux-dependent amplitude of broadband noise variability in X-ray binaries and active galaxies (2001)

Uttley, Philip, McHardy, Ian M.

Standard shot-noise models, which seek to explain the broadband noise variability that characterises the X-ray lightcurves of X-ray binaries and active galaxies, predict that the power spectrum of...