45 citations · 205 across the 22 of their papers we have counts for
14 papers · 1 filter
Untangling the Complex Nature of AGN Variability with Fairall 9
Scott Hagen, Chris Done, Edward M. Cackett +5
The accretion flow in AGN is not well understood, motivating intensive monitoring campaigns of multiwavelength variability to probe its structure. One of the best of these is the 3…
The Accretion Disk Size Problem in AGN Disk Reverberation Mapping is an Obscuration Effect: A Uniform AGN Sample Study with Swift
Collin Lewin, Erin Kara, Christos Panagiotou +5
In the past decade, Swift has performed several AGN high-cadence reverberation mapping campaigns, and generally found that the UV/optical interband lags are 3 times longer th…
AGN STORM 2. VII. A Frequency-resolved Map of the Accretion Disk in Mrk 817: Simultaneous X-ray Reverberation and UVOIR Disk Reprocessing Time Lags
Collin Lewin, Erin Kara, Aaron J. Barth +35
X-ray reverberation mapping is a powerful technique for probing the innermost accretion disk, whereas continuum reverberation mapping in the UV, optical, and infrared (UVOIR) revea…
AGN STORM 2: IX. Studying the Dynamics of the Ionized Obscurer in Mrk 817 with High-resolution X-ray Spectroscopy
Fatima Zaidouni, Erin Kara, Peter Kosec +45
We present the results of the XMM-Newton and NuSTAR observations taken as part of the ongoing, intensive multi-wavelength monitoring program of the Seyfert 1 galaxy Mrk 817 by the…
AT2018fyk: Candidate Tidal Disruption Event by a (Super)massive Black Hole Binary
S. Wen, P. G. Jonker, A. J. Levan +8
The tidal disruption event (TDE) AT2018fyk has unusual X-ray, UV, and optical light curves that decay over the first 600d, rebrighten, and decay again around 1200d. We explai…
Highly-coherent quasi-periodic oscillations in the 'heartbeat' black hole X-ray binary IGR J17091-3624
Jingyi Wang, Erin Kara, Jeroen Homan +13
IGR J17091-3624 is a black hole X-ray binary (BHXB), often referred to as the 'twin' of GRS 1915+105 because it is the only other known BHXB that can show exotic 'heartbeat'-like v…
The 2022 Outburst of IGR J17091-3624: Connecting the exotic GRS 1915+105 to standard black hole X-ray binaries
Jingyi Wang, Erin Kara, Javier A. García +13
While the standard X-ray variability of black hole X-ray binaries (BHXBs) is stochastic and noisy, there are two known BHXBs that exhibit exotic `heartbeat'-like variability in the…
Variability as a predictor for the hard-to-soft state transition in GX 339-4
Matteo Lucchini, Marina Ten Have, Jingyi Wang +17
During the outbursts of black hole X-ray binaries (BHXRBs), their accretion flows transition through several states. The source luminosity rises in the hard state, dominated by non…
AGN STORM 2. VI. Mapping Temperature Fluctuations in the Accretion Disk of Mrk 817
Jack M. M. Neustadt, Christopher S. Kochanek, John Montano +49
We fit the UV/optical lightcurves of the Seyfert 1 galaxy Mrk 817 to produce maps of the accretion disk temperature fluctuations resolved in time and radius. The maps are…
X-ray/UVOIR Frequency-resolved Time Lag Analysis of Mrk 335 Reveals Accretion Disk Reprocessing
Collin Lewin, Erin Kara, Edward M. Cackett +4
UV and optical continuum reverberation mapping is powerful for probing the accretion disk and inner broad-line region. However, recent reverberation mapping campaigns in the X-ray,…
Investigating the impact of vertically extended coronae on X-ray reverberation mapping
Matteo Lucchini, Guglielmo Mastroserio, Jingyi Wang +9
Accreting black holes commonly exhibit hard X-ray emission, originating from a region of hot plasma near the central engine referred to as the corona. The origin and geometry of th…
UV/Optical disk reverberation lags despite a faint X-ray corona in the AGN Mrk 335
Erin Kara, Aaron J. Barth, Edward M. Cackett +37
We present the first results from a 100-day Swift, NICER and ground-based X-ray/UV/optical reverberation mapping campaign of the Narrow-Line Seyfert 1 Mrk 335, when it was in an un…
X-ray Reverberation Mapping of Ark 564 using Gaussian Process Regression
Collin D. Lewin, Erin Kara, Daniel R. Wilkins +15
Ark 564 is an extreme high-Eddington Narrow-line Seyfert 1 galaxy, known for being one of the brightest, most rapidly variable soft X-ray AGN, and for having one of the lowest temp…
Maximum mass and universal relations of rotating relativistic hybrid hadron-quark stars
Gabriele Bozzola, Pedro Luis Espino, Collin Davis Lewin +1
We construct equilibrium models of uniformly and differentially rotating hybrid hadron-quark stars using equations of state (EOSs) with a first-order phase transition that gives ri…