Timing the Pulsations of the Accreting Millisecond Pulsar SAX J1808.4–3658 during Its 2019 Outburst
In this paper we present a coherent timing analysis of the 401 Hz pulsations of the accreting millisecond X-ray pulsar SAX J1808.4-3658 during its 2019 outburst. Using observations collected with the Neutron Star Interior Composition Explorer (NICER), we establish the pulsar spin frequency and orbit...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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American Astronomical Society
2020
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| Online Access: | https://hdl.handle.net/1721.1/128769 |
| _version_ | 1826198361762430976 |
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| author | Bult, Peter Chakrabarty, Deepto Arzoumanian, Zaven Gendreau, Keith C. Guillot, Sebastien Malacaria, Christian Ray, Paul. S. Strohmayer, Tod E. |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Bult, Peter Chakrabarty, Deepto Arzoumanian, Zaven Gendreau, Keith C. Guillot, Sebastien Malacaria, Christian Ray, Paul. S. Strohmayer, Tod E. |
| author_sort | Bult, Peter |
| collection | MIT |
| description | In this paper we present a coherent timing analysis of the 401 Hz pulsations of the accreting millisecond X-ray pulsar SAX J1808.4-3658 during its 2019 outburst. Using observations collected with the Neutron Star Interior Composition Explorer (NICER), we establish the pulsar spin frequency and orbital phase during its latest epoch. We find that the 2019 outburst shows a pronounced evolution in pulse phase over the course of the outburst. These phase shifts are found to correlate with the source flux and are interpreted in terms of hot-spot drift on the stellar surface, driven by changes in the mass accretion rate. Additionally, we find that the long-term evolution of the pulsar spin frequency shows evidence for a modulation at the Earth's orbital period, allowing for pulsar timing based astrometry of this accreting millisecond pulsar. |
| first_indexed | 2024-09-23T11:03:39Z |
| format | Article |
| id | mit-1721.1/128769 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T11:03:39Z |
| publishDate | 2020 |
| publisher | American Astronomical Society |
| record_format | dspace |
| spelling | mit-1721.1/1287692022-10-01T00:53:07Z Timing the Pulsations of the Accreting Millisecond Pulsar SAX J1808.4–3658 during Its 2019 Outburst Bult, Peter Chakrabarty, Deepto Arzoumanian, Zaven Gendreau, Keith C. Guillot, Sebastien Malacaria, Christian Ray, Paul. S. Strohmayer, Tod E. MIT Kavli Institute for Astrophysics and Space Research In this paper we present a coherent timing analysis of the 401 Hz pulsations of the accreting millisecond X-ray pulsar SAX J1808.4-3658 during its 2019 outburst. Using observations collected with the Neutron Star Interior Composition Explorer (NICER), we establish the pulsar spin frequency and orbital phase during its latest epoch. We find that the 2019 outburst shows a pronounced evolution in pulse phase over the course of the outburst. These phase shifts are found to correlate with the source flux and are interpreted in terms of hot-spot drift on the stellar surface, driven by changes in the mass accretion rate. Additionally, we find that the long-term evolution of the pulsar spin frequency shows evidence for a modulation at the Earth's orbital period, allowing for pulsar timing based astrometry of this accreting millisecond pulsar. 2020-12-09T22:36:07Z 2020-12-09T22:36:07Z 2020-07 2020-05 2020-09-22T17:06:04Z Article http://purl.org/eprint/type/JournalArticle 1538-4357 https://hdl.handle.net/1721.1/128769 Bult, Peter et al. "Timing the Pulsations of the Accreting Millisecond Pulsar SAX J1808.4–3658 during Its 2019 Outburst. " Astrophysical Journal 898, 1 (July 2020): 38 © 2020 The American Astronomical Society en http://dx.doi.org/10.3847/1538-4357/ab9827 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Astronomical Society The American Astronomical Society |
| spellingShingle | Bult, Peter Chakrabarty, Deepto Arzoumanian, Zaven Gendreau, Keith C. Guillot, Sebastien Malacaria, Christian Ray, Paul. S. Strohmayer, Tod E. Timing the Pulsations of the Accreting Millisecond Pulsar SAX J1808.4–3658 during Its 2019 Outburst |
| title | Timing the Pulsations of the Accreting Millisecond Pulsar SAX J1808.4–3658 during Its 2019 Outburst |
| title_full | Timing the Pulsations of the Accreting Millisecond Pulsar SAX J1808.4–3658 during Its 2019 Outburst |
| title_fullStr | Timing the Pulsations of the Accreting Millisecond Pulsar SAX J1808.4–3658 during Its 2019 Outburst |
| title_full_unstemmed | Timing the Pulsations of the Accreting Millisecond Pulsar SAX J1808.4–3658 during Its 2019 Outburst |
| title_short | Timing the Pulsations of the Accreting Millisecond Pulsar SAX J1808.4–3658 during Its 2019 Outburst |
| title_sort | timing the pulsations of the accreting millisecond pulsar sax j1808 4 3658 during its 2019 outburst |
| url | https://hdl.handle.net/1721.1/128769 |
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