activity
20242026
collaborators

5 papers

astro-ph.GA2026

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…

astro-ph.HE2026

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…

astro-ph.HE2025

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…

astro-ph.HE2024

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…

astro-ph.HE2024

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…