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Your search keyword '"Dominic J. Walton"' showing total 11 results
Start Over Author "Dominic J. Walton" Publication Type Reports
11 results on '"Dominic J. Walton"'

1. Gaia GraL: Gaia DR2 gravitational lens systems – VIII. A radio census of lensed systems

Author

Dougal Dobie, Dominique Sluse, Adam Deller, Tara Murphy, Alberto Krone-Martins, Daniel Stern, Ziteng Wang, Yuanming Wang, Céline Bœhm, S G Djorgovski, Laurent Galluccio, Ludovic Delchambre, Thomas Connor, Jakob Sebastiaan den Brok, Pedro H Do Vale Cunha, Christine Ducourant, Matthew J Graham, Priyanka Jalan, Sergei A Klioner, Jonas Klüter, François Mignard, Vibhore Negi, Quentin Petit, Sergio Scarano, Eric Slezak, Jean Surdej, Ramachrisna Teixeira, Dominic J Walton, and Joachim Wambsganss

Published
2024
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3. Unusual Hard X-Ray Flares Caught in NICER Monitoring of the Binary Supermassive Black Hole Candidate AT2019cuk/Tick Tock/SDSS J1430+2303

Author

Megan Masterson, Erin Kara, Dheeraj R. Pasham, Daniel J. D’Orazio, Dominic J. Walton, Andrew C. Fabian, Matteo Lucchini, Ronald A. Remillard, Zaven Arzoumanian, Otabek Burkhonov, Hyeonho Choi, Shuhrat A. Ehgamberdiev, Elizabeth C. Ferrara, Muryel Guolo, Myungshin Im, Yonggi Kim, Davron O. Mirzaqulov, Gregory S. H. Paek, Hyun-Il Sung, and Joh-Na Yoon

Published
2023
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4. The Tidal Disruption Event AT2021ehb: Evidence of Relativistic Disk Reflection, and Rapid Evolution of the Disk–Corona System

Author

Yuhan Yao, Wenbin Lu, Muryel Guolo, Dheeraj R. Pasham, Suvi Gezari, Marat Gilfanov, Keith C. Gendreau, Fiona Harrison, S. Bradley Cenko, S. R. Kulkarni, Jon M. Miller, Dominic J. Walton, Javier A. García, Sjoert van Velzen, Kate D. Alexander, James C. A. Miller-Jones, Matt Nicholl, Erica Hammerstein, Pavel Medvedev, Daniel Stern, Vikram Ravi, R. Sunyaev, Joshua S. Bloom, Matthew J. Graham, Erik C. Kool, Ashish A. Mahabal, Frank J. Masci, Josiah Purdum, Ben Rusholme, Yashvi Sharma, Roger Smith, and Jesper Sollerman

Published
2022
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9. A ~60 day Super-orbital Period Originating from the Ultraluminous X-ray Pulsar in M82

Author

Murray Brightman, Fiona A Harrison, Matteo Bachetti, Yanjun Xu, Felix Fürst, Dominic J. Walton, Andrew Francis Ptak, Mihoko Yukita, and Andreas Zezas

Subjects
Astronomy
Abstract

Ultraluminous X-ray (ULX) pulsars are a new class of object powered by apparent super-critical accretion onto magnetized neutron stars. Three sources in this class have been identified so far; M82X-2, NGC 5907 ULX-1, and NGC 7793 P13 have been found to have two properties in common; ∼1 s spin periods, and for NGC 5907 ULX-1 and NGC 7793 P13 periodic X-ray flux modulations on timescales of ∼60–80 days. M82 X-2 resides in a crowded field that includes the ULX M82 X-1 separated from X-2 by 5″, as well as other bright point sources. A 60 day modulation has been observed from the region, but the origin has been difficult to identify; both M82 X-1 and X-2 have been suggested as the source. In this paper we present the analysis of a systematic monitoring campaign by Chandra, the only X-ray telescope capable of resolving the crowded field. From a simple Lomb–Scargle periodogram analysis and a more sophisticated Gaussian Process analysis we find that only X-2 exhibits a periodic signal around 60 days, supporting previous claims that it is the origin. We also construct a phase-averaged flux profile of the modulations from higher-cadence Swift/XRT data and find that the flux variations in the Chandra data are fully consistent with the flux profile. Since the orbit of the neutron star and its companion is known to be 2.5 days, the ∼60 day period must be super-orbital in origin. The flux of the modulations varies by a factor of ∼100 from the minimum to the maximum, with no evidence for spectral variations, making the origin difficult to explain.

Published
2019
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