Detection of millihertz quasi-periodic oscillations in the low-mass X-ray binary 4U 1730--22 with NICER
Detection of millihertz quasi-periodic oscillations in the low-mass X-ray binary 4U 1730--22 with NICER
We report the discovery of millihertz quasi-periodic oscillations (mHz QPOs) from the neutron star (NS) low-mass X-ray binary 4U 1730-22 using the Neutron Star Interior Composition Explorer (NICER). After being inactive for almost 50 years, 4U 1730-22 went into outburst twice between June and August 2021, and between February and July 2022. We analyse all the NICER observations of this source, and detect mHz QPOs with a significance > 4 σ in 35 observations. The QPO frequency of the full data set ranged between ∼4.5 and ∼8.1 mHz with an average fractional rms amplitude of the order of ∼2 per cent. The X-ray colour analysis strongly suggests that 4U 1730-22 was in a soft spectral state during the QPO detections. Our findings are consistent with those reported for other sources where the mHz QPOs have been interpreted as the result of a special mode of He burning on the NS surface called marginally stable nuclear burning (MSNB). We conclude that the mHz QPOs reported in this work are also associated with the MSNB, making 4U 1730-22 the eighth source that shows this phenomenology. We discuss our findings in the context of the heat flux from the NS crust.
astro-ph.HE, stars: individual: 4U 1730 - 22, X-rays: binaries, accretion, accretion discs, stars: neutron
5616-5623
Mancuso, G.C.
ac7509c1-5491-4d83-8835-05ae6ba1db01
Altamirano, D.
d5ccdb09-0b71-4303-9538-05b467be075b
Bult, P.
875075f1-179b-4de0-8676-86bb7dc37879
Chenevez, J.
25a95602-9e3d-4553-a442-5f4317ff2cd6
Guillot, S.
5d521f37-303f-4a40-9f85-fbb75b960f12
Guver, T.
e8cdef32-2de7-43b5-b34c-325c01f0bfab
Jaisawal, G. K.
4d5dcd39-0881-426d-8ad7-f378238405ae
Malacaria, C.
98e428d9-76cc-4cb2-9451-dbdc956505b1
Ng, M.
df52da90-69c9-4106-a09d-6f07e90f87ff
Sanna, A.
b925b305-171b-461f-bbf7-1c8fe246293c
Strohmayer, T.E.
491eee42-6b4e-4dcc-a7cd-2a36ac992a7d
1 June 2023
Mancuso, G.C.
ac7509c1-5491-4d83-8835-05ae6ba1db01
Altamirano, D.
d5ccdb09-0b71-4303-9538-05b467be075b
Bult, P.
875075f1-179b-4de0-8676-86bb7dc37879
Chenevez, J.
25a95602-9e3d-4553-a442-5f4317ff2cd6
Guillot, S.
5d521f37-303f-4a40-9f85-fbb75b960f12
Guver, T.
e8cdef32-2de7-43b5-b34c-325c01f0bfab
Jaisawal, G. K.
4d5dcd39-0881-426d-8ad7-f378238405ae
Malacaria, C.
98e428d9-76cc-4cb2-9451-dbdc956505b1
Ng, M.
df52da90-69c9-4106-a09d-6f07e90f87ff
Sanna, A.
b925b305-171b-461f-bbf7-1c8fe246293c
Strohmayer, T.E.
491eee42-6b4e-4dcc-a7cd-2a36ac992a7d
Mancuso, G.C., Altamirano, D., Bult, P., Chenevez, J., Guillot, S., Guver, T., Jaisawal, G. K., Malacaria, C., Ng, M., Sanna, A. and Strohmayer, T.E.
(2023)
Detection of millihertz quasi-periodic oscillations in the low-mass X-ray binary 4U 1730--22 with NICER.
Monthly Notices of the Royal Astronomical Society, 521 (4), .
(doi:10.1093/mnras/stad949).
Abstract
We report the discovery of millihertz quasi-periodic oscillations (mHz QPOs) from the neutron star (NS) low-mass X-ray binary 4U 1730-22 using the Neutron Star Interior Composition Explorer (NICER). After being inactive for almost 50 years, 4U 1730-22 went into outburst twice between June and August 2021, and between February and July 2022. We analyse all the NICER observations of this source, and detect mHz QPOs with a significance > 4 σ in 35 observations. The QPO frequency of the full data set ranged between ∼4.5 and ∼8.1 mHz with an average fractional rms amplitude of the order of ∼2 per cent. The X-ray colour analysis strongly suggests that 4U 1730-22 was in a soft spectral state during the QPO detections. Our findings are consistent with those reported for other sources where the mHz QPOs have been interpreted as the result of a special mode of He burning on the NS surface called marginally stable nuclear burning (MSNB). We conclude that the mHz QPOs reported in this work are also associated with the MSNB, making 4U 1730-22 the eighth source that shows this phenomenology. We discuss our findings in the context of the heat flux from the NS crust.
Text
2304.09935v1
- Author's Original
Available under License Other.
More information
Accepted/In Press date: 24 March 2023
e-pub ahead of print date: 29 March 2023
Published date: 1 June 2023
Additional Information:
Funding Information:
GCM acknowledges support from the Royal Society International Exchanges 'the first step for High-Energy Astrophysics relations between Argentina and the UK'. DA acknowledges support from the Ro yal Society. GCM w as partially supported by PIP 0113 (CONICET). This work received financial support from PICT-2017- 2865 (ANPCyT). PB acknowledges support from NASA through the Astrophysics Data Analysis Program (80NSSC20K0288) and the CRESST II cooperative agreement (80GSFC21M0002). SG acknowledges the support of the CNES. TG has been supported in part by the Turkish Republic, Presidency of Strategy and Budget project, 2016K121370.
Publisher Copyright:
© 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
Keywords:
astro-ph.HE, stars: individual: 4U 1730 - 22, X-rays: binaries, accretion, accretion discs, stars: neutron
Identifiers
Local EPrints ID: 478160
URI: http://eprints.soton.ac.uk/id/eprint/478160
ISSN: 1365-2966
PURE UUID: b1f348dd-502b-497f-aae5-8f292e654d90
Catalogue record
Date deposited: 23 Jun 2023 16:36
Last modified: 17 Mar 2024 03:34
Export record
Altmetrics
Contributors
Author:
G.C. Mancuso
Author:
P. Bult
Author:
J. Chenevez
Author:
S. Guillot
Author:
T. Guver
Author:
G. K. Jaisawal
Author:
C. Malacaria
Author:
M. Ng
Author:
A. Sanna
Author:
T.E. Strohmayer
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
