The University of Southampton
University of Southampton Institutional Repository

Discovery of coherent pulsations from the Ultraluminous X-ray Source NGC 7793 P13

Discovery of coherent pulsations from the Ultraluminous X-ray Source NGC 7793 P13
Discovery of coherent pulsations from the Ultraluminous X-ray Source NGC 7793 P13
We report the detection of coherent pulsations from the ultraluminous X-ray source (ULX) NGC 7793 P13. The ≈0.42 s nearly sinusoidal pulsations were initially discovered in broadband X-ray observations using XMM-Newton and NuSTAR taken in 2016. We subsequently also found pulsations in archival XMM-Newton data taken in 2013 and 2014. The significant (Gt5σ) detection of coherent pulsations demonstrates that the compact object in P13 is a neutron star, and given the observed peak luminosity of ≈1040 $\mathrm{erg}\,{{\rm{s}}}^{-1}$ (assuming isotropy), it is well above the Eddington limit for a 1.4 ${M}_{\odot }$ accretor. This makes P13 the second ULX known to be powered by an accreting neutron star. The pulse period varies between epochs, with a slow but persistent spin-up over the 2013–2016 period. This spin-up indicates a magnetic field of B ≈ 1.5 × 1012 G, typical of many Galactic accreting pulsars. The most likely explanation for the extreme luminosity is a high degree of beaming; however, this is difficult to reconcile with the sinusoidal pulse profile.
2041-8205
Furst, F.
b85eb74e-a1c3-4861-ac7b-6e273c052920
Walton, D.J.
a1a36b18-a77b-48e8-8665-45bbef0c7bd1
Harrison, F.A.
b71f286a-75db-46ef-8953-bd41865e74bc
Stern, D.
a573010b-ca8e-4018-b0f5-4621657713b3
Barret, D.
343cdacd-9683-4f70-910b-6539201daf06
Brightman, M.
eb110ae1-9a2c-4968-b9ef-e7955feba535
Fabian, A.C.
0c353376-f159-4129-b03e-d3993c0c5406
Grefenstette, B.
a0a616bc-d751-4cbd-b54d-6b927b6a4fc4
Madsen, K.K.
c11f81e9-5003-40eb-950a-361da4f1e843
Middleton, M.J.
f91b89d9-fd2e-42ec-aa99-1249f08a52ad
Miller, J.M.
02ad9de2-e507-44f6-b76c-f30621fbf9f5
Pottschmidt, K.
bd76c555-32b0-4f86-a07b-4fbee8dda440
Ptak, A.
62af2a20-131f-4fa3-86ae-4e30b579e1b2
Rana, V.
4f96a272-7944-47f3-905a-b7569a994cc2
Webb, N.
fd029073-c1c4-4a04-876a-d2371d074d48
Furst, F.
b85eb74e-a1c3-4861-ac7b-6e273c052920
Walton, D.J.
a1a36b18-a77b-48e8-8665-45bbef0c7bd1
Harrison, F.A.
b71f286a-75db-46ef-8953-bd41865e74bc
Stern, D.
a573010b-ca8e-4018-b0f5-4621657713b3
Barret, D.
343cdacd-9683-4f70-910b-6539201daf06
Brightman, M.
eb110ae1-9a2c-4968-b9ef-e7955feba535
Fabian, A.C.
0c353376-f159-4129-b03e-d3993c0c5406
Grefenstette, B.
a0a616bc-d751-4cbd-b54d-6b927b6a4fc4
Madsen, K.K.
c11f81e9-5003-40eb-950a-361da4f1e843
Middleton, M.J.
f91b89d9-fd2e-42ec-aa99-1249f08a52ad
Miller, J.M.
02ad9de2-e507-44f6-b76c-f30621fbf9f5
Pottschmidt, K.
bd76c555-32b0-4f86-a07b-4fbee8dda440
Ptak, A.
62af2a20-131f-4fa3-86ae-4e30b579e1b2
Rana, V.
4f96a272-7944-47f3-905a-b7569a994cc2
Webb, N.
fd029073-c1c4-4a04-876a-d2371d074d48

Furst, F., Walton, D.J., Harrison, F.A., Stern, D., Barret, D., Brightman, M., Fabian, A.C., Grefenstette, B., Madsen, K.K., Middleton, M.J., Miller, J.M., Pottschmidt, K., Ptak, A., Rana, V. and Webb, N. (2016) Discovery of coherent pulsations from the Ultraluminous X-ray Source NGC 7793 P13. The Astrophysical Journal Letters, 831 (2), [L14]. (doi:10.3847/2041-8205/831/2/L14).

Record type: Article

Abstract

We report the detection of coherent pulsations from the ultraluminous X-ray source (ULX) NGC 7793 P13. The ≈0.42 s nearly sinusoidal pulsations were initially discovered in broadband X-ray observations using XMM-Newton and NuSTAR taken in 2016. We subsequently also found pulsations in archival XMM-Newton data taken in 2013 and 2014. The significant (Gt5σ) detection of coherent pulsations demonstrates that the compact object in P13 is a neutron star, and given the observed peak luminosity of ≈1040 $\mathrm{erg}\,{{\rm{s}}}^{-1}$ (assuming isotropy), it is well above the Eddington limit for a 1.4 ${M}_{\odot }$ accretor. This makes P13 the second ULX known to be powered by an accreting neutron star. The pulse period varies between epochs, with a slow but persistent spin-up over the 2013–2016 period. This spin-up indicates a magnetic field of B ≈ 1.5 × 1012 G, typical of many Galactic accreting pulsars. The most likely explanation for the extreme luminosity is a high degree of beaming; however, this is difficult to reconcile with the sinusoidal pulse profile.

Text
DISCOVERY OF COHERENT PULSATIONS FROM THE ULTRALUMINOUS X-RAY SOURCE NGC 7793 P13 - Accepted Manuscript
Restricted to Repository staff only
Request a copy
Text
furst-2016 - Version of Record
Available under License Other.
Download (897kB)

More information

Accepted/In Press date: 15 October 2016
e-pub ahead of print date: 3 November 2016
Published date: 3 November 2016
Additional Information: Arxiv record Author Middleton confirms AM
Organisations: Astronomy Group

Identifiers

Local EPrints ID: 412026
URI: http://eprints.soton.ac.uk/id/eprint/412026
ISSN: 2041-8205
PURE UUID: ed4b833f-76b8-46d9-b253-82dc878d75bd

Catalogue record

Date deposited: 05 Jul 2017 16:31
Last modified: 15 Mar 2024 15:07

Export record

Altmetrics

Contributors

Author: F. Furst
Author: D.J. Walton
Author: F.A. Harrison
Author: D. Stern
Author: D. Barret
Author: M. Brightman
Author: A.C. Fabian
Author: B. Grefenstette
Author: K.K. Madsen
Author: M.J. Middleton
Author: J.M. Miller
Author: K. Pottschmidt
Author: A. Ptak
Author: V. Rana
Author: N. Webb

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.

×