Coti Zelati, F;
Rea, N;
Turolla, R;
Pons, JA;
Papitto, A;
Esposito, P;
Israel, GL;
... Elfritz, J; + view all
(2017)
Chandra monitoring of the Galactic Centre magnetar SGR J1745−2900 during the initial 3.5 years of outburst decay.
Monthly Notices of the Royal Astronomical Society
, 471
(2)
pp. 1819-1829.
10.1093/mnras/stx1700.
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Abstract
We report on 3.5 yr of Chandra monitoring of the Galactic Centre magnetar SGR J1745−2900 since its outburst onset in 2013 April. The magnetar spin-down has shown at least two episodes of period derivative increases so far, and it has slowed down regularly in the past year or so. We observed a slightly increasing trend in the time evolution of the pulsed fraction, up to ∼55 per cent in the most recent observations. SGR J1745−2900 has not reached the quiescent level yet, and so far the overall outburst evolution can be interpreted in terms of a cooling hot region on the star surface. We discuss possible scenarios, showing in particular how the presence of a shrinking hotspot in this source is hardly reconcilable with internal crustal cooling and favours the untwisting bundle model for this outburst. Moreover, we also show how the emission from a single uniform hotspot is incompatible with the observed pulsed fraction evolution for any pair of viewing angles, suggesting an anisotropic emission pattern.
| Type: | Article |
|---|---|
| Title: | Chandra monitoring of the Galactic Centre magnetar SGR J1745−2900 during the initial 3.5 years of outburst decay |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stx1700 |
| Publisher version: | http://doi.org/10.1093/mnras/stx1700 |
| Language: | English |
| Additional information: | © 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Methods: data analysis, methods: observational, stars: magnetars, Galaxy: centre, X-rays: individual: SGR J1745−2900 |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10025927 |
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