32 citations · 33 across the 3 of their papers we have counts for
5 papers · 1 filter
Discovering periodic and repeating nuclear transients in the XMM-Newton archives
Natalie A. Webb, Vincent Foustoul, Robbie Webbe +3
The regions around massive black holes can show X-ray variability on timescales from seconds to decades. Observing many black holes over different timescales can enhance our chance…
4XMM J175136.8-275858: A New Magnetar Candidate?
Robbie Webbe, Norman Khan, N. A. Webb +1
Magnetars are very rare astrophysical objects, with 31 known to date. They are best understood as highly magnetised neutron stars, but a greater number need to be found to co…
Probing the nature of the low state in the extreme ultraluminous X-ray pulsar NGC 5907 ULX1
F. Fuerst, D. J. Walton, G. L. Israel +13
NGC 5907 ULX1 is the most luminous ultra-luminous X-ray pulsar (ULXP) known to date, reaching luminosities in excess of 1e41 erg/s. The pulsar is known for its fast spin-up during…
A new candidate pulsating ULX in NGC 7793
Erwan Quintin, Natalie Webb, Andrés Gúrpide +2
We report here the discovery of NGC 7793 ULX-4, a new transient ultraluminous X-ray source (ULX) in NGC 7793, a spiral galaxy already well known for harbouring several ULXs. This n…
A Potential Cyclotron Resonant Scattering Feature in the ULX Pulsar NGC 300 ULX1 seen by NuSTAR and XMM-Newton
D. J. Walton, M. Bachetti, F. Fuerst +14
Based on phase-resolved broadband spectroscopy using - and , we report on a potential cyclotron resonant scattering feature at keV in the pulsed sp…