@article{1e58980ba06e42bea142802225de9661,
title = "The variable spin-down rate of the transient magnetar XTE J1810-197",
abstract = "We have analysed XMM-Newton and Chandra observations of the transient magnetar XTE J1810-197 spanning more than 11 yr, from the initial phases of the 2003 outburst to the current quiescent level. We investigated the evolution of the pulsar spin period and we found evidence for two distinct regimes: during the outburst decay, v˙ was highly variable in the range -(2-4.5) × 10-13 Hz s-1, while during quiescence the spin-down rate was more stable at an average value of -1 × 10-13 Hz s-1. Only during ~3000 d (from MJD 54165 to MJD 56908) in the quiescent stage it was possible to find a phase-connected timing solution, with v˙ =-4.9 × 10-14 Hz s-1, and a positive second frequency derivative, v =1.8 × 10-22 Hz s-2. These results are in agreement with the behaviour expected if the outburst of XTE J1810-197 was due to a strong magnetospheric twist.",
keywords = "Magnetic fields, Pulsars: Individual: (XTE J1810-197), Stars: Magnetars, Stars: Neutron, X-rays: Stars",
author = "Fabio Pintore and Federico Bernardini and Sandro Mereghetti and Paolo Esposito and Roberto Turolla and Nanda Rea and {Coti Zelati}, Francesco and Israel, {Gian Luca} and Andrea Tiengo and Silvia Zane",
note = "Funding Information: We thank Rosalba Perna and Simone Dall?Osso for their useful suggestions. This work has been partially supported through financial contributions from the agreement ASI/INAF I/037/12/0 and from PRIN INAF 2014. FB acknowledges support for analysis of XMM-Newton data provided by NASA though award number NNX14AF66G from the Astrophysics Data analysis Program (ADAP). FB also acknowledges support for analysis of Chandra data provided by NASA through Chandra Award Number GO4- 15066X issued by the Chandra X-ray Observatory Center. NR and FCZ are supported by an NWO Vidi Grant, and by the European COST Action MP1304 (NewCOMPSTAR). This work is based on data from observations with XMM?Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA). Funding Information: We thank Rosalba Perna and Simone Dall{\textquoteright}Osso for their useful suggestions. This work has been partially supported through financial contributions from the agreement ASI/INAF I/037/12/0 and from PRIN INAF 2014. FB acknowledges support for analysis of XMM-Newton data provided by NASA though award number NNX14AF66G from the Astrophysics Data analysis Program (ADAP). FB also acknowledges support for analysis of Chandra data provided by NASA through Chandra Award Number GO4- 15066X issued by the Chandra X-ray Observatory Center. NR and FCZ are supported by an NWO Vidi Grant, and by the European COST Action MP1304 (NewCOMPSTAR). This work is based on data from observations with XMM–Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA). Publisher Copyright: {\textcopyright} 2016 The Authors.",
year = "2016",
month = mar,
day = "2",
doi = "10.1093/mnras/stw351",
language = "English (US)",
volume = "458",
pages = "2088--2093",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "2",
}