Search Publications
Intrinsic disc emission and the soft X-ray excess in active galactic nuclei
Done, Chris; Ward, M.; Jin, C. +2 more
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 should peak in the extreme ultraviolet. However, the lack of true absorption opacity in the disc means that the emission is better approximated by a colour temperature corrected blackbod…
Ubiquitous equatorial accretion disc winds in black hole soft states
Ponti, G.; Fender, R. P.; Neilsen, J. +3 more
High-resolution spectra of Galactic black holes (GBHs) reveal the presence of highly ionized absorbers. In one GBH, accreting close to the Eddington limit for more than a decade, a powerful accretion disc wind is observed to be present in softer X-ray states and it has been suggested that it can carry away enough mass and energy to quench the radi…
Using the Bright Ultrahard XMM-Newton survey to define an IR selection of luminous AGN based on WISE colours
Stern, D.; Barcons, X.; Blain, A. +7 more
We present a highly complete and reliable mid-infrared (MIR) colour selection of luminous active galactic nucleus (AGN) candidates using the 3.4, 4.6 and 12 µm bands of the Wide-field Infrared Survey Explorer (WISE) survey. The MIR colour wedge was defined using the wide-angle Bright Ultrahard XMM-Newton survey (BUXS), one of the largest com…
Using the Fundamental Plane of black hole activity to distinguish X-ray processes from weakly accreting black holes
Anderson, Scott F.; Plotkin, Richard M.; Markoff, Sera +2 more
The Fundamental Plane of black hole activity is a relation between X-ray luminosity, radio luminosity and black hole mass for hard-state Galactic black holes and their supermassive analogues. The Fundamental Plane suggests that, at low-accretion rates, the physical processes regulating the conversion of an accretion flow into radiative energy coul…
Evidence for ultrafast outflows in radio-quiet AGNs - III. Location and energetics
Cappi, M.; Tombesi, F.; Reeves, J. N. +1 more
Using the results of a previous X-ray photoionization modelling of blueshifted Fe K absorption lines on a sample of 42 local radio-quiet AGNs observed with XMM-Newton, in this Letter we estimate the location and energetics of the associated ultrafast outflows (UFOs). Due to significant uncertainties, we are essentially able to place only lower/upp…
X-ray surface brightness and gas density fluctuations in the Coma cluster
Böhringer, H.; Sunyaev, R.; Churazov, E. +6 more
X-ray surface brightness fluctuations in the core (650 × 650 kpc) region of the Coma cluster observed with XMM-Newton and Chandra are analysed using a 2D power spectrum approach. The resulting 2D spectra are converted to 3D power spectra of gas density fluctuations. Our independent analyses of the XMM-Newton and Chandra observations are in excelle…
A combined optical and X-ray study of unobscured type 1 active galactic nuclei - I. Optical spectra and spectral energy distribution modelling
Done, Chris; Ward, Martin; Jin, Chichuan +1 more
We present modelling and interpretation of the continuum and emission lines for a sample of 51 unobscured type 1 active galactic nuclei (AGNs). All of these AGNs have high-quality spectra from both XMM-Newton and the Sloan Digital Sky Survey. We extend the wavelength coverage where possible by adding simultaneous ultraviolet data from the OM onboa…
The XMM Cluster Survey: optical analysis methodology and the first data release
Hilton, Matt; Stanford, S. A.; Stott, John P. +36 more
The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling relations. In this paper we present the first data release from the XMM Cluster Survey (XCS-DR1). This consists…
Relativistic iron K X-ray reverberation in NGC 4151
Fabian, A. C.; Reynolds, C. S.; Cackett, E. M. +1 more
Recent X-ray observations have enabled the study of reverberation delays in active galactic nuclei (AGN) for the first time. All the detections so far are in sources with a strong soft excess, and the measured delay is between the hard (1-3 keV) direct continuum and the soft excess (0.5-1 keV), interpreted as the reflection continuum smeared by re…
Discovery of radio haloes and double relics in distant MACS galaxy clusters: clues to the efficiency of particle acceleration
Vazza, F.; Edge, A. C.; Bonafede, A. +6 more
We have performed 323 MHz observations with the Giant Metrewave Radio Telescope of the most promising candidates selected from the MACS catalogue. The aim of the work is to extend our knowledge of the radio halo and relic populations to z > 0.3, the epoch in which massive clusters are formed. In MACSJ1149.5+2223 and MACSJ1752.1+4440, we discove…