330 citations · 791 across the 11 of their papers we have counts for
11 papers
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…
Discovery of coherent pulsations from the Ultraluminous X-ray Source NGC 7793 P13
F. Fuerst, D. J. Walton, F. A. Harrison +12
We report the detection of coherent pulsations from the ultraluminous X-ray source NGC 7793 P13. The ~0.42s nearly sinusoidal pulsations were initially discovered in broadband X-ra…
A 78 Day X-ray Period Detected from NGC 5907 ULX1 by Swift
D. J. Walton, F. Fuerst, M. Bachetti +12
We report the detection of a day period in the X-ray lightcurve of the extreme ultraluminous X-ray source NGC 5907 ULX1 ( erg s$^{-1…
A search for hyperluminous X-ray sources in the XMM-Newton source catalog
Ivan Zolotukhin, Natalie A. Webb, Olivier Godet +2
We present a new method to identify luminous off-nuclear X-ray sources in the outskirts of galaxies from large public redshift surveys, distinguishing them from foreground and back…
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…
The XMM-Newton SSC survey of the Galactic Plane
A. Nebot Gomez-Moran, C. Motch, X. Barcons +17
Many different classes of X-ray sources contribute to the Galactic landscape at high energies. Although the nature of the most luminous X-ray emitters is now fairly well understood…