The University of Southampton
University of Southampton Institutional Repository

The newly discovered Be/X-ray binary Swift J004516.6-734703 in the SMC: witnessing the emergence of a circumstellar disc

The newly discovered Be/X-ray binary Swift J004516.6-734703 in the SMC: witnessing the emergence of a circumstellar disc
The newly discovered Be/X-ray binary Swift J004516.6-734703 in the SMC: witnessing the emergence of a circumstellar disc
We report on the discovery of Swift J004516.6–734703, a Be/X-ray binary system by the Swift SMC Survey, S-CUBED. Swift J004516.6–734703, or SXP 146.6, was found to be exhibiting a bright (∼1037 erg s−1) X-ray outburst on 2020 June 18. The historical UV and IR light-curves from OGLE and Swift/UVOT showed that after a long period of steady brightness, it experienced a significant brightening beginning around 2019 March. This IR/UV rise is likely the signature of the formation of a circumstellar disc, confirmed by the presence of strong an H α line in SALT spectroscopy, that was not previously present. Periodicity analysis of the OGLE data reveals a plausible 426 d binary period, and in X-ray a pulsation period of 146.6 s is detected. The onset of X-ray emission from Swift J004516.6–734703 is likely the signature of a Type-I outburst from the first periastron passage of the neutron star companion through the newly formed circumstellar disc. We note that the formation of the circumstellar disc began at the predicted time of the previous periastron passage, suggesting its formation was spurred by tidal interaction with the neutron star.
1745-3925
L41-L46
Kennea, J.A.
5bda466b-abb9-42be-a687-4eeb9c602d67
Coe, M.J.
04dfb23b-1456-46a3-9242-5cee983471d5
Evans, P.A.
7c0ccb9f-4062-4f21-9835-171fef390d7c
Monageng, I.M.
ea1baf78-c23c-4531-afbd-640eea0dacb3
Townsend, L.J.
383d1487-54d3-4912-82d3-1cc3b4b28d5e
Siegel, M.H.
e764220b-2c79-467b-b6ba-0194a5e0d75d
Udalski, A.
320fdc94-b983-41cd-ad0d-0aee565e7142
Buckley, D.A.H.
ea3b9dda-bd50-4635-8911-0f0f9d2c5ccc
Kennea, J.A.
5bda466b-abb9-42be-a687-4eeb9c602d67
Coe, M.J.
04dfb23b-1456-46a3-9242-5cee983471d5
Evans, P.A.
7c0ccb9f-4062-4f21-9835-171fef390d7c
Monageng, I.M.
ea1baf78-c23c-4531-afbd-640eea0dacb3
Townsend, L.J.
383d1487-54d3-4912-82d3-1cc3b4b28d5e
Siegel, M.H.
e764220b-2c79-467b-b6ba-0194a5e0d75d
Udalski, A.
320fdc94-b983-41cd-ad0d-0aee565e7142
Buckley, D.A.H.
ea3b9dda-bd50-4635-8911-0f0f9d2c5ccc

Kennea, J.A., Coe, M.J., Evans, P.A., Monageng, I.M., Townsend, L.J., Siegel, M.H., Udalski, A. and Buckley, D.A.H. (2020) The newly discovered Be/X-ray binary Swift J004516.6-734703 in the SMC: witnessing the emergence of a circumstellar disc. Monthly Notices of the Royal Astronomical Society: Letters, 499 (1), L41-L46. (doi:10.1093/mnrasl/slaa154).

Record type: Article

Abstract

We report on the discovery of Swift J004516.6–734703, a Be/X-ray binary system by the Swift SMC Survey, S-CUBED. Swift J004516.6–734703, or SXP 146.6, was found to be exhibiting a bright (∼1037 erg s−1) X-ray outburst on 2020 June 18. The historical UV and IR light-curves from OGLE and Swift/UVOT showed that after a long period of steady brightness, it experienced a significant brightening beginning around 2019 March. This IR/UV rise is likely the signature of the formation of a circumstellar disc, confirmed by the presence of strong an H α line in SALT spectroscopy, that was not previously present. Periodicity analysis of the OGLE data reveals a plausible 426 d binary period, and in X-ray a pulsation period of 146.6 s is detected. The onset of X-ray emission from Swift J004516.6–734703 is likely the signature of a Type-I outburst from the first periastron passage of the neutron star companion through the newly formed circumstellar disc. We note that the formation of the circumstellar disc began at the predicted time of the previous periastron passage, suggesting its formation was spurred by tidal interaction with the neutron star.

Text
The newly discovered BeX-ray binary Swift J004516.6-734703 in the SMC witnessing the emergence of a circumstellar disc - Accepted Manuscript
Download (589kB)

More information

Accepted/In Press date: 28 August 2020
e-pub ahead of print date: 10 September 2020
Published date: November 2020

Identifiers

Local EPrints ID: 445443
URI: http://eprints.soton.ac.uk/id/eprint/445443
ISSN: 1745-3925
PURE UUID: d8d137a8-13b1-4d31-820f-c3182d5c1fb7
ORCID for M.J. Coe: ORCID iD orcid.org/0000-0002-0763-8547

Catalogue record

Date deposited: 09 Dec 2020 17:30
Last modified: 18 Feb 2021 16:34

Export record

Altmetrics

Contributors

Author: J.A. Kennea
Author: M.J. Coe ORCID iD
Author: P.A. Evans
Author: I.M. Monageng
Author: L.J. Townsend
Author: M.H. Siegel
Author: A. Udalski
Author: D.A.H. Buckley

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×