418 citations · 491 across the 7 of their papers we have counts for
5 papers · 1 filter
The variability of active galaxies: I. Broad-band noise X-ray power spectra from XMM-Newton and Swift
Mehdy Lefkir, Simon Vaughan, Mike Goad +2
Accreting supermassive black holes at the centres of galaxies are the engine of active galactic nuclei (AGN). X-ray light curves of unabsorbed AGN show dramatic random variability…
Long term variability of Cygnus X-1. IX. A spectral-timing comparison of Cygnus X-1 and MAXI J1820+070 in the hard state
Arkadip Basak, Phil Uttley, Niek Bollemeijer +11
Cygnus X-1 is a persistent, high-mass black hole X-ray binary (BHXRB) which in the hard state shows many similar properties to transient BHXRBs, along with intriguing differences,…
Intensive broadband reverberation mapping of Fairall 9 with 1.8 years of daily Swift monitoring
R. Edelson, B. M. Peterson, J. Gelbord +5
We present 1.8 years of near-daily Swift monitoring of the bright, strongly variable Type 1 AGN Fairall 9. Totaling 575 successful visits, this is the largest such campaign reporte…
Investigating the Hard State of MAXI J1820+070: A Comprehensive Bayesian Approach to Black Hole Spin and Accretion Properties
Sachin D. Dias, Simon Vaughan, Mehdy Lefkir +1
We analyse the X-ray spectrum of the black hole X-ray binary MAXI J1820+070 using observations from XMM-Newton and NuSTAR during 'hard' states of its 2018-2019 outburst. We take a…
Kepler observations of rapid optical variability in the BL Lac object W2R1926+42
R. Edelson, R. Mushotzky, S. Vaughan +4
We present the first Kepler monitoring of a strongly variable BL Lac, W2R1926+42. The light curve covers 181 days with ~0.2% errors, 30 minute sampling and >90% duty cycle, showing…