Anticorrelation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323
Anticorrelation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323
We report the evidence for the anticorrelation between pulsed fraction (PF) and luminosity of the X-ray pulsar SXP 1323, found for the first time in a luminosity range 1035-1037 erg s-1 from observations spanning 15 yr. The phenomenon of a decrease in X-ray PF when the source flux increases has been observed in our pipeline analysis of other X-ray pulsars in the Small Magellanic Cloud. It is expected that the luminosity under a certain value decreases as the PF decreases due to the propeller effect. Above the propeller region, an anticorrelation between the PF and the flux might occur either as a result of an increase in the unpulsed component of the total emission or a decrease of the pulsed component. Additional modes of accretion may also be possible, such as spherical accretion and a change in emission geometry. At higher mass accretion rates, the accretion disc could also extend closer to the neutron star surface, where a reduced inner radius leads to hotter inner disc emission. These modes of plasma accretion may affect the change in the beam configuration to fan-beam dominant emission.
Pulsars: individual: SXP 1323, X-rays: binaries
L1-L6
Yang, Jun
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Zezas, Andreas
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Coe, Malcolm J.
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Drake, Jeremy J.
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Hong, Jae Sub
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Laycock, Silas G.T.
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Wik, Daniel R.
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September 2018
Yang, Jun
47673b30-c7b5-4342-a34f-9f506c1804a3
Zezas, Andreas
b09e794a-5973-4f3d-bdb1-6a709e560df8
Coe, Malcolm J.
04dfb23b-1456-46a3-9242-5cee983471d5
Drake, Jeremy J.
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Hong, Jae Sub
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Laycock, Silas G.T.
d4e5bb78-7038-4e42-aaf5-9fdc20f60037
Wik, Daniel R.
f4f10fac-a438-44be-8cdf-ebe76ce0c7be
Yang, Jun, Zezas, Andreas, Coe, Malcolm J., Drake, Jeremy J., Hong, Jae Sub, Laycock, Silas G.T. and Wik, Daniel R.
(2018)
Anticorrelation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323.
Monthly Notices of the Royal Astronomical Society: Letters, 479 (1), .
(doi:10.1093/mnrasl/sly085).
Abstract
We report the evidence for the anticorrelation between pulsed fraction (PF) and luminosity of the X-ray pulsar SXP 1323, found for the first time in a luminosity range 1035-1037 erg s-1 from observations spanning 15 yr. The phenomenon of a decrease in X-ray PF when the source flux increases has been observed in our pipeline analysis of other X-ray pulsars in the Small Magellanic Cloud. It is expected that the luminosity under a certain value decreases as the PF decreases due to the propeller effect. Above the propeller region, an anticorrelation between the PF and the flux might occur either as a result of an increase in the unpulsed component of the total emission or a decrease of the pulsed component. Additional modes of accretion may also be possible, such as spherical accretion and a change in emission geometry. At higher mass accretion rates, the accretion disc could also extend closer to the neutron star surface, where a reduced inner radius leads to hotter inner disc emission. These modes of plasma accretion may affect the change in the beam configuration to fan-beam dominant emission.
Text
Anticorrelation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323
- Accepted Manuscript
Text
sly085
- Version of Record
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Accepted/In Press date: 8 May 2018
e-pub ahead of print date: 14 May 2018
Published date: September 2018
Keywords:
Pulsars: individual: SXP 1323, X-rays: binaries
Identifiers
Local EPrints ID: 425638
URI: http://eprints.soton.ac.uk/id/eprint/425638
ISSN: 1745-3925
PURE UUID: c7f4b787-ed8a-4798-8ec5-6ff36632454e
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Date deposited: 30 Oct 2018 17:30
Last modified: 16 Mar 2024 02:35
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Contributors
Author:
Jun Yang
Author:
Andreas Zezas
Author:
Jeremy J. Drake
Author:
Jae Sub Hong
Author:
Silas G.T. Laycock
Author:
Daniel R. Wik
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