59 citations · 68 across the 10 of their papers we have counts for
10 papers
Gaia GraL X.: The GraL catalogue of gravitationally lensed quasars Matched with \textit{Gaia} data, redshifts, and time delays
C. Ducourant, R. Teixeira, P. H. Vale-Cunha +25
Determining the Hubble constant tension requires alternative strategies, and multiply imaged quasars, with their intermediate redshifts, can potentially be used in this regard. We…
Constraining black hole spin in PG 1535+547 amidst complex multi-layered absorption
A. Madathil-Pottayil, D. J. Walton, Jiachen Jiang +7
We present a spectroscopic analysis of XMM-Newton and NuSTAR observations of the 'complex' NLS1 PG 1535+547 at redshift . These observations span three epochs: 2002 and 20…
The Broadband View of the Bare Seyfert PG 1426+015: Relativistic Reflection, the Soft Excess and the Importance of Oxygen
D. J. Walton, A. Madathil-Pottayil, P. Kosec +8
We present results from a deep, coordinated - + observation of the type 1 Seyfert PG 1426+015, a source of particular interest as the most massive reverberati…
Exploring the high-density reflection model for the soft excess in RBS 1124
A. Madathil-Pottayil, D. J. Walton, Javier García +13
'Bare' active galactic nuclei (AGN) are a subclass of Type 1 AGN that show little or no intrinsic absorption. They offer an unobscured view of the central regions of the AGN and th…
A New Broadband Spectral State in the Ultraluminous X-ray Source Holmberg IX X-1
D. J. Walton, M. Bachetti, P. Kosec +12
We present a series of five new broadband X-ray observations of the ultraluminous X-ray source Holmberg IX X-1, performed by - and in coordination. The first…
The First High-Contrast Images of Near High-Mass X-Ray Binaries with Keck/NIRC2
M. Prasow-Émond, J. Hlavacek-Larrondo, K. Fogarty +10
Although the study of X-ray binaries has led to major breakthroughs in high-energy astrophysics, their circumbinary environment at scales of 100--10,000 astronomical units ha…
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…
Modelling the Extreme X-ray Spectrum of IRAS 13224-3809
Chia-Ying Chiang, D. J. Walton, A. C. Fabian +2
The extreme NLS1 galaxy IRAS 13224-3809 shows significant variability, frequency depended time lags, and strong Fe K line and Fe L features in the long 2011 XMM-Newton observation.…