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On the curious pulsation properties of the accreting millisecond pulsar IGR J17379-3747

On the curious pulsation properties of the accreting millisecond pulsar IGR J17379-3747
On the curious pulsation properties of the accreting millisecond pulsar IGR J17379-3747
We report on the Neutron Star Interior Composition Explorer (NICER) monitoring campaign of the 468 Hz accreting millisecond X-ray pulsar IGR J17379–3747. From a detailed spectral and timing analysis of the coherent pulsations we find that they show a strong energy dependence, with soft thermal emission lagging about 640 μs behind the hard, Comptonized emission. Additionally, we observe uncommonly large pulse fractions, with measured amplitudes in excess of 20% sinusoidal fractional amplitude across the NICER passband and fluctuations of up to ~70%. Based on a phase-resolved spectral analysis, we suggest that these extreme properties might be explained if the source has an unusually favorable viewing geometry with a large magnetic misalignment angle. Due to these large pulse fractions, we were able to detect pulsations down to quiescent luminosities ($\sim 5\times {10}^{33}$ erg ${{\rm{s}}}^{-1}$). We discuss these low-luminosity pulsations in the context of transitional millisecond pulsars.
0004-637X
Bult, Peter
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Markwardt, Craig B.
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Altamirano, Diego
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Arzoumanian, Zaven
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Chakrabarty, Deepto
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Gendreau, Keith C.
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Guillot, Sebastien
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Jaisawal, Gaurava K.
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Ray, Paul S.
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Strohmayer, Tod E.
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Bult, Peter
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Markwardt, Craig B.
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Altamirano, Diego
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Arzoumanian, Zaven
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Chakrabarty, Deepto
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Gendreau, Keith C.
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Guillot, Sebastien
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Jaisawal, Gaurava K.
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Ray, Paul S.
ae47ba31-71c4-4b29-805e-02536a978cd7
Strohmayer, Tod E.
1371d451-4cdb-48ca-812b-e5ddd6c3f204

Bult, Peter, Markwardt, Craig B., Altamirano, Diego, Arzoumanian, Zaven, Chakrabarty, Deepto, Gendreau, Keith C., Guillot, Sebastien, Jaisawal, Gaurava K., Ray, Paul S. and Strohmayer, Tod E. (2019) On the curious pulsation properties of the accreting millisecond pulsar IGR J17379-3747. The Astrophysical Journal, 877 (2). (doi:10.3847/1538-4357/ab1b26).

Record type: Article

Abstract

We report on the Neutron Star Interior Composition Explorer (NICER) monitoring campaign of the 468 Hz accreting millisecond X-ray pulsar IGR J17379–3747. From a detailed spectral and timing analysis of the coherent pulsations we find that they show a strong energy dependence, with soft thermal emission lagging about 640 μs behind the hard, Comptonized emission. Additionally, we observe uncommonly large pulse fractions, with measured amplitudes in excess of 20% sinusoidal fractional amplitude across the NICER passband and fluctuations of up to ~70%. Based on a phase-resolved spectral analysis, we suggest that these extreme properties might be explained if the source has an unusually favorable viewing geometry with a large magnetic misalignment angle. Due to these large pulse fractions, we were able to detect pulsations down to quiescent luminosities ($\sim 5\times {10}^{33}$ erg ${{\rm{s}}}^{-1}$). We discuss these low-luminosity pulsations in the context of transitional millisecond pulsars.

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On the Curious Pulsation Properties of the Accreting Millisecond Pulsar IGR J17379-3747 - Accepted Manuscript
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Accepted/In Press date: 18 April 2019
Published date: 28 May 2019
Additional Information: arXiv is AM

Identifiers

Local EPrints ID: 432039
URI: http://eprints.soton.ac.uk/id/eprint/432039
ISSN: 0004-637X
PURE UUID: d990e99d-11a5-496d-b667-4dd69b866c4a
ORCID for Diego Altamirano: ORCID iD orcid.org/0000-0002-3422-0074

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Date deposited: 27 Jun 2019 16:30
Last modified: 16 Mar 2024 04:17

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Contributors

Author: Peter Bult
Author: Craig B. Markwardt
Author: Zaven Arzoumanian
Author: Deepto Chakrabarty
Author: Keith C. Gendreau
Author: Sebastien Guillot
Author: Gaurava K. Jaisawal
Author: Paul S. Ray
Author: Tod E. Strohmayer

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