The University of Southampton
University of Southampton Institutional Repository
Warning ePrints Soton is experiencing an issue with some file downloads not being available. We are working hard to fix this. Please bear with us.

Discovery of a thermonuclear Type I X-ray burst in infrared: new limits on the orbital period of 4U 1728-34

Discovery of a thermonuclear Type I X-ray burst in infrared: new limits on the orbital period of 4U 1728-34
Discovery of a thermonuclear Type I X-ray burst in infrared: new limits on the orbital period of 4U 1728-34
We report the detection of an infrared burst lagging a thermonuclear Type I X-ray burst from the accreting neutron star (NS) 4U 1728-34 (GX 354-0). Observations were performed simultaneously with XMM–Newton (0.7–12 keV), NuSTAR (3–79 keV), and HAWK-I@VLT (2.2 μm). We measure a lag of 4.75 ± 0.5 s between the peaks of the emission in the two bands. Due to the length of the lag and the shape of the IR burst, we found that the most plausible cause for such a large delay is reprocessing of the Type I burst X-rays by the companion star. The inferred distance between the NS and the companion can be used to constrain the orbital period of the system, which we find to be larger than ∼66 min (or even ≳2 h, for a realistic inclination <75°). This is much larger than the current tentatively estimated period of ∼11 min. We discuss the physical implications on the nature of the binary and conclude that most likely the companion of 4U 1728-34 is a helium star.
1745-3925
L37-L41
Vincentelli, F M
6059e516-6e7a-4d18-afa4-c5b68a3b207a
Cavecchi, Y
939cba7d-c099-4d5a-a962-1fee916ea176
Casella, P
c254f195-d43d-4385-98ef-d33600fb7f81
Migliari, S
aa759820-ecfe-416d-87e4-75c3f5b04b3f
Altamirano, D
d5ccdb09-0b71-4303-9538-05b467be075b
Belloni, T
a6a0a7f0-68d9-411a-97ee-75479ce1aeac
Diaz-trigo, M
78381e12-43ad-47ec-b82e-a2d13e201cba
Vincentelli, F M
6059e516-6e7a-4d18-afa4-c5b68a3b207a
Cavecchi, Y
939cba7d-c099-4d5a-a962-1fee916ea176
Casella, P
c254f195-d43d-4385-98ef-d33600fb7f81
Migliari, S
aa759820-ecfe-416d-87e4-75c3f5b04b3f
Altamirano, D
d5ccdb09-0b71-4303-9538-05b467be075b
Belloni, T
a6a0a7f0-68d9-411a-97ee-75479ce1aeac
Diaz-trigo, M
78381e12-43ad-47ec-b82e-a2d13e201cba

Vincentelli, F M, Cavecchi, Y, Casella, P, Migliari, S, Altamirano, D, Belloni, T and Diaz-trigo, M (2020) Discovery of a thermonuclear Type I X-ray burst in infrared: new limits on the orbital period of 4U 1728-34. Monthly Notices of the Royal Astronomical Society: Letters, 495 (1), L37-L41. (doi:10.1093/mnrasl/slaa049).

Record type: Article

Abstract

We report the detection of an infrared burst lagging a thermonuclear Type I X-ray burst from the accreting neutron star (NS) 4U 1728-34 (GX 354-0). Observations were performed simultaneously with XMM–Newton (0.7–12 keV), NuSTAR (3–79 keV), and HAWK-I@VLT (2.2 μm). We measure a lag of 4.75 ± 0.5 s between the peaks of the emission in the two bands. Due to the length of the lag and the shape of the IR burst, we found that the most plausible cause for such a large delay is reprocessing of the Type I burst X-rays by the companion star. The inferred distance between the NS and the companion can be used to constrain the orbital period of the system, which we find to be larger than ∼66 min (or even ≳2 h, for a realistic inclination <75°). This is much larger than the current tentatively estimated period of ∼11 min. We discuss the physical implications on the nature of the binary and conclude that most likely the companion of 4U 1728-34 is a helium star.

Text
2003.08403 - Accepted Manuscript
Download (344kB)

More information

Accepted/In Press date: 18 March 2020
e-pub ahead of print date: 10 April 2020
Published date: 11 June 2020

Identifiers

Local EPrints ID: 442344
URI: http://eprints.soton.ac.uk/id/eprint/442344
ISSN: 1745-3925
PURE UUID: eded9758-a928-4135-b1fa-d5e048f2eb0d
ORCID for Y Cavecchi: ORCID iD orcid.org/0000-0002-6447-3603
ORCID for D Altamirano: ORCID iD orcid.org/0000-0002-3422-0074

Catalogue record

Date deposited: 14 Jul 2020 16:30
Last modified: 26 Nov 2021 03:02

Export record

Altmetrics

Contributors

Author: F M Vincentelli
Author: Y Cavecchi ORCID iD
Author: P Casella
Author: S Migliari
Author: D Altamirano ORCID iD
Author: T Belloni
Author: M Diaz-trigo

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.

×