165 citations · 708 across the 13 of their papers we have counts for
13 papers
The absence of a thin disc in M81
A. J. Young, I. McHardy, D. Emmanoulopoulos +1
We present the results of simultaneous Suzaku and NuSTAR observations of the nearest Low-Luminosity Active Galactic Nucleus (LLAGN), M81*. The spectrum is well described by a cut-o…
X-ray/UV/optical variability of NGC 4593 with Swift: Reprocessing of X-rays by an extended reprocessor
I M McHardy, S D Connolly, K Horne E M Cackett +25
We report the results of intensive X-ray, UV and optical monitoring of the Seyfert 1 galaxy NGC 4593 with Swift. There is no intrinsic flux-related spectral change in the the varia…
Swift monitoring of NGC 4151: Evidence for a Second X-ray/UV Reprocessing
R. Edelson, J. Gelbord, E. Cackett +41
Swift monitoring of NGC 4151 with ~6 hr sampling over a total of 69 days in early 2016 is used to construct light curves covering five bands in the X-rays (0.3-50 keV) and six in t…
Correlated X-ray/UV/optical variability and the nature of accretion disc in the bare Seyfert 1 galaxy Fairall~9
Main Pal, Gulab C. Dewangan, S. D. Connolly +1
We study multi-wavelength variability of a bare Seyfert 1 galaxy Fairall~9 using \swift{} monitoring observations consisting of usable pointings spanning nearly two years and…
Long-term X-Ray Spectral Variability in AGN from the Palomar sample observed by Swift
S. D. Connolly, I. M. McHardy, C. J. Skipper +1
We present X-ray spectral variability of 24 local active galactic nuclei (AGN) from the Palomar sample of nearby galaxies, as observed mainly by Swift. From hardness ratio measurem…
The Origin of UV-optical Variability in AGN and Test of Disc Models: XMM-Newton and ground based observations of NGC4395
Ian McHardy, Sam Connolly, Brad Peterson +12
The origin of short timescale (weeks/months) variability of AGN, whether due to intrinsic disc variations or reprocessing of X-ray emission by a surrounding accretion disc, has bee…
A new period of activity in the core of NGC660
Megan Argo, Ilse van Bemmel, Sam Connolly +1
The core of the nearby galaxy NGC660 has recently undergone a spectacular radio outburst; using a combination of archival radio and Chandra X-ray data, together with new observatio…
A Python Code for the Emmanoulopoulos et al. [arXiv:1305.0304] Light Curve Simulation Algorithm
S D Connolly
I have created, for public use, a Python code allowing the simulation of light curves with any given power spectral density and any probability density function, following the algo…
The largest Swift AGN monitoring campaign: UV/optical variability in NGC 5548
S. D. Connolly, I. M. McHardy, D. T. Cameron +7
We report on the largest Swift AGN monitoring program, concerning UV/optical variability in Seyferts. From 554 observations, over a 750d period, of the Seyfert galaxy NGC 5548, we…
Swift monitoring of NGC 5548: X-ray reprocessing and short term UV/optical variability
I. M. McHardy, D. T. Cameron, T. Dwelly +7
Lags measured from correlated X-ray/UV/optical monitoring of AGN allow us to determine whether UV/optical variability is driven by reprocessing of X-rays or X-ray variability is dr…
Long Term Wind-Driven X-Ray Spectral Variability of NGC 1365 with Swift
S. D. Connolly, I. M. McHardy, T. Dwelly
We present long-term (months-years) X-ray spectral variability of the Seyfert 1.8 galaxy NGC 1365 as observed by Swift, which provides well sampled observations over a much longer…
Variability of the accretion disk of V926 Sco inferred from tomographic analysis
S. D. Connolly, C. S. Peris, S. D. Vrtilek
We present phase-resolved spectroscopic observations of the low-mass X-ray binary V926 Sco (4U 1735-44), covering the orbital period of 0.23d, obtained with the Walter Baade 6.5m M…
Confirmation of 1RXS J165443.5-191620 as an intermediate polar and its orbital and spin periods
S. Scaringi, S. Connolly, J. Patterson +12
Aims: We investigate the physical nature of the X-ray emitting source 1RXS J165443.5-191620 through optical photometry and time-resolved spectroscopy. Methods: Optical photometry i…