158 citations · 1.2k across the 16 of their papers we have counts for
16 papers
Investigating the Periodic X-ray Behaviour in the Eclipsing AGN NGC 6814
T. O. Hodd, L. C. Gallo, A. G. Gonzalez +2
A 2016 XMM-Newton X-ray light curve of the Seyfert 1.5 galaxy NGC 6814 exhibited clear eclipsing behaviour, with distinct ingress and egress, during half of the observation. Here,…
On the Fe xxii Emission in the X-ray spectrum of NGC 1068
M. Z. Buhariwalla, J. M. Miller, L. C. Gallo +3
The Fe xxii doublet has been previously used to determine the density of collisionally ionized emission from magnetic cataclysmic variable stars. We test how this diagnostic double…
A Spectral Energy Distribution Variability Study of the Eclipsing AGN NGC 6814
L. K. Pothier-Bogoslowski, L. C. Gallo, A. G. Gonzalez +2
The local Seyfert 1.5 active galactic nucleus (AGN), NGC 6814, is known to exhibit complex variability, eclipses, and even changing-look behaviour. In this work, we utilize optical…
Simultaneous NICER and NuSTAR Observations of the Neutron Star Low-mass X-ray Binary Serpens X-1
H. Hall, R. M. Ludlam, J. M. Miller +5
We present the first contemporaneous NICER and NuSTAR analysis of the low-mass X-ray binary Serpens X-1 obtained in June 2023, performing broadband X-ray spectral analysis modeling…
A NICER Discovery of a Low-Frequency Quasi-Periodic Oscillation in the Soft-Intermediate State of MAXI J1535-571
A. L. Stevens, P. Uttley, D. Altamirano +17
We present the discovery of a low-frequency Hz quasi-periodic oscillation (QPO) feature in observations of the black hole X-ray binary MAXI J1535-571 in its soft-inte…
A Hard Look at the Neutron Stars and Accretion Disks in 4U 1636-53, GX 17+2, and 4U 1705-44 with
R. M. Ludlam, J. M. Miller, M. Bachetti +9
We present observations of neutron star (NS) low-mass X-ray binaries: 4U 1636-53, GX 17+2, and 4U 1705-44. We observed 4U 1636-53 in the hard state, with an Eddingt…
Living on a Flare: Relativistic Reflection in V404 Cyg Observed by NuSTAR During its Summer 2015 Outburst
D. J. Walton, K. Mooley, A. L. King +19
We present first results from a series of observations of the black hole X-ray binary V404 Cyg obtained during its summer 2015 outburst, primarily focusing on observations…
An Iron K Component to the Ultrafast Outflow in NGC 1313 X-1
D. J. Walton, M. J. Middleton, C. Pinto +8
We present the detection of an absorpton feature at keV in the combined X-ray spectrum of the ultraluminous X-ray source NGC 1313 X-1 observed with XMM-New…
Hitomi constraints on the 3.5 keV line in the Perseus galaxy cluster
Hitomi Collaboration, Felix A. Aharonian, Hiroki Akamatsu +215
High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified E=3.5 keV emission line reported in several low-resolution studies of va…
NuSTAR and Suzaku observations of the hard state in Cygnus X-1: locating the inner accretion disk
M. L. Parker, J. A. Tomsick, J. M. Miller +20
We present simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR ) and Suzaku observations of the X-ray binary Cygnus X-1 in the hard state. This is the first time this state…
The NuSTAR spectrum of Mrk 335: Extreme relativistic effects within 2 gravitational radii of the event horizon?
M. L. Parker, D. R. Wilkins, A. C. Fabian +18
We present 3-50 keV NuSTAR observations of the AGN Mrk 335 in a very low flux state. The spectrum is dominated by very strong features at the energies of the iron line at 5-7 keV a…
NuSTAR and XMM-Newton Observations of NGC 1365: Extreme Absorption Variability and a Constant Inner Accretion Disk
D. J. Walton, G. Risaliti, F. A. Harrison +24
We present a spectral analysis of four coordinated NuSTAR+XMM-Newton observations of the Seyfert galaxy NGC 1365. These exhibit an extreme level of spectral variability, which is p…
Multi-Wavelength Coverage of State Transitions in the New Black Hole X-Ray Binary Swift J1910.2-0546
N. Degenaar, D. Maitra, E. M. Cackett +11
Understanding how black holes accrete and supply feedback to their environment is one of the outstanding challenges of modern astrophysics. Swift J1910.2-0546 is a candidate black…
Broadband X-ray Spectra of the Ultraluminous X-ray Source Holmberg IX X-1 observed with NuSTAR, XMM-Newton and Suzaku
D. J. Walton, F. A. Harrison, B. W. Grefenstette +16
We present results from the coordinated broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 performed by NuSTAR, XMM-Newton and Suzaku in late 20…
An Extremely Luminous and Variable Ultraluminous X-ray Source in the Outskirts of Circinus Observed with NuSTAR
D. J. Walton, F. Fuerst, F. A. Harrison +16
Following a serendipitous detection with the NuSTAR observatory, we present a multi-epoch spectral and temporal analysis of an extreme ultraluminous X-ray source (ULX) located in t…
Chandra-HETGS Observations of the Brightest Flare Seen from Sgr A*
M. A. Nowak, J. Neilsen, S. B. Markoff +10
Starting in 2012, we began an unprecedented observational program focused on the supermassive black hole in the center of our Galaxy, Sgr A*, utilizing the High Energy Transmission…