254 citations · 1.9k across the 35 of their papers we have counts for
35 papers
AT2021yky: A Fast-Rising Optical Transient with Evolving Broad Hydrogen Emission Consistent with an Ambiguous Nuclear Transient
Paarmita Pandey, Jason T. Hinkle, Christopher Kochanek +14
Nuclear transients are powerful probes of supermassive black hole properties, offering insight into black hole mass, accretion physics, and the structure of galactic nuclei. Among…
Time-resolved XRISM spectroscopy reveals the evolution and structure of the corona in MCG-6-30-15
D. R. Wilkins, L. W. Brenneman, A. Ogorzalek +7
We present a time-resolved analysis of high-resolution spectra of the AGN MCG-6-30-15 obtained by XRISM alongside broadband spectra from NuSTAR and XMM-Newton during a coordinated…
Blueshifted lines from the inner accretion disc's rotation can explain quasar absorption "forests''
Amelia M. Hankla, Fergus J. E. Baker, Daniel R. Wilkins +1
Recent XRISM observations of active galactic nuclei such as PDS 456 have revealed ``forests'' of absorption lines best modeled by five distinct absorption zones with varying large…
The Effects of Complex Accretion Disk Geometry on Broadened Iron K Lines
William Surgent, Daniel R. Wilkins
X-rays are emitted from the corona above the orbiting matter of the accretion disk and travel either directly to us or illuminate the disk. This illumination of the inner disk is e…
Variability of the X-ray obscuring wind in Mrk 335 with XMM-Newton/RGS
Daniele Rogantini, Erin Kara, Luigi Gallo +10
Transient X-ray obscuration in Seyfert 1 galaxies likely arises from clumpy accretion-disk winds near the broad-line region (BLR), but the wind structure and short-timescale variab…
A Sharper View of the X-ray Spectrum of MCG--6-30-15 with XRISM, XMM-Newton and NuSTAR
Laura W. Brenneman, Daniel R. Wilkins, Anna Ogorzałek +15
We present a time-averaged spectral analysis of the 2024 XRISM observation of the narrow-line Seyfert-1 galaxy MCG--6-30-15, taken contemporaneously with XMM-Newton and NuSTAR. Our…
An Exceptionally Powerful, Radiatively Driven Ultrafast Outflow in the Rapidly Accreting AGN REJ1034+396
Chloe Taylor, Daniel Wilkins, Steven Allen
We report the analysis of ~1Ms of XMM-Newton observations of the rapidly accreting active galactic nucleus REJ1034+396. The 0.3-9 keV EPIC-pn spectra are well described by a model…
A View of the Long-Term Spectral Behavior of Ultra Compact X-Ray Binary 4U 0614+091
David L. Moutard, Renee M. Ludlam, Edward M. Cackett +3
In this study, we examine 51 archival NICER observations and 6 archival NuSTAR observations of the neutron star (NS) ultra-compact X-ray binary (UCXB) 4U 0614+091, which span over…
The outflowing ionised gas of I Zw 1 observed by HST COS
A. Juráňová, E. Costantini, G. A. Kriss +8
We present an analysis of the HST COS spectrum of IZw1 aiming to probe the absorbing medium associated with the active galactic nucleus (AGN). We fitted the emission spectrum and p…
The High Energy X-ray Probe (HEX-P): The Circum-nuclear Environment of Growing Supermassive Black Holes
P. G. Boorman, N. Torres-Albà, A. Annuar +32
Ever since the discovery of the first Active Galactic Nuclei (AGN), substantial observational and theoretical effort has been invested into understanding how massive black holes ha…
The High Energy X-ray Probe (HEX-P): Constraining Supermassive Black Hole Growth with Population Spin Measurements
J. M. Piotrowska, J. A. García, D. J. Walton +24
Constraining the primary growth channel of supermassive black holes (SMBH) remains one the most actively debated questions in the context of cosmological structure formation. Owing…
The High Energy X-ray Probe (HEX-P): Probing the physics of the X-ray corona in active galactic nuclei
E. Kammoun, A. M. Lohfink, M. Masterson +28
The hard X-ray emission in active galactic nuclei (AGN) and black hole X-ray binaries is thought to be produced by a hot cloud of electrons referred to as the corona. This emission…
Discovery of soft and hard X-ray time lags in low-mass AGNs
Labani Mallick, Daniel R. Wilkins, William N. Alston +5
The scaling relations between the black hole (BH) mass and soft lag properties for both active galactic nuclei (AGNs) and BH X-ray binaries (BHXRBs) suggest the same underlying phy…
Returning radiation in strong gravity around black holes: Reverberation from the accretion disc
D. R. Wilkins, J. A. García, T. Dauser +1
We study reflected X-ray emission that returns to the accretion disc in the strong gravitational fields around black holes using General Relativistic ray tracing and radiative tran…
Evidence for an emerging disc wind and collimated outflow during an X-ray flare in the narrow-line Seyfert 1 galaxy Mrk 335
L. C. Gallo, A. G. Gonzalez, S. G. H. Waddell +13
A triggered 140 ks XMM-Newton observation of the narrow-line Seyfert 1 (NLS1) Mrk 335 in December 2015 caught the active galaxy at its lowest X-ray flux since 2007. The NLS1 is rel…
The remarkable X-ray variability of IRAS 13224-3809 I: The variability process
W. N. Alston, A. C. Fabian, D. J. K. Buisson +17
We present a detailed X-ray timing analysis of the highly variable NLS1 galaxy, IRAS 13224-3809. The source was recently monitored for 1.5 Ms with XMM-Newton which, combined with 5…
Is there a UV/X-ray connection in IRAS 13224-3809?
D. J. K. Buisson, A. M. Lohfink, W. N. Alston +16
We present results from the optical, ultraviolet and X-ray monitoring of the NLS1 galaxy IRAS 13224-3809 taken with Swift and XMM-Newton during 2016. IRAS 13224-3809 is the most va…
On the illumination of neutron star accretion discs
D. R. Wilkins
The illumination of the accretion disc in a neutron star X-ray binary by X-rays emitted from (or close to) the neutron star surface is explored through general relativistic ray tra…
The high-Eddington NLS1 Ark 564 has the coolest corona
E. Kara, J. A. Garcia, A. Lohfink +4
Ark 564 is an archetypal Narrow line Seyfert 1 that has been well observed in soft X-rays from 0.3-10 keV, revealing a steep spectrum, strong soft excess, iron K emission line and…
The Future of X-ray Reverberation from AGN
A. C. Fabian, W. N. Alston, E. M. Cackett +3
XMM-Newton is capable of making a transformational advance in our understanding of how luminous accreting black holes work, by dedicating about 10 per cent of future observing time…
Towards modelling X-ray reverberation in AGN: Piecing together the extended corona
D. R. Wilkins, E. M. Cackett, A. C. Fabian +1
Models of X-ray reverberation from extended coronae are developed from general relativistic ray tracing simulations. Reverberation lags between correlated variability in the direct…
Driving Extreme Variability - Measuring the evolving coronae and evidence for jet launching in AGN
D. R. Wilkins
Relativistically blurred reflection from the accretion disc provides a powerful probe of the extreme environments close to supermassive black holes; the inner regions of the accret…
Driving extreme variability: The evolving corona and evidence for jet launching in Markarian 335
D. R. Wilkins, L. C. Gallo
Variations in the X-ray emission from the narrow line Seyfert 1 galaxy, Markarian 335 (Mrk 335), are studied on both long and short timescales through observations made between 200…
Suzaku observations of Mrk 335: Confronting partial covering and relativistic reflection
L. C. Gallo, D. R. Wilkins, K. Bonson +7
We report on the deepest X-ray observation of the narrow-line Seyfert 1 galaxy Mrk 335 in the low-flux state obtained with Suzaku. The data are compared to a 2006 high-flux Suzaku…