The X-ray evolution and geometry of the 2018 outburst of XTE J1810-197

After 15 yr, in late 2018, the magnetar XTE J1810-197 underwent a second recorded X-ray outburst event and reactivated as a radio pulsar. We initiated an X-ray monitoring campaign to follow the timing and spectral evolution of the magnetar as its flux decays using Swift, XMM-Newton, NuSTAR, and NICE...

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Detalles Bibliográficos
Autores: Borghese, Alice, Rea, Nanda, Rigoselli, Michela, Alford, J. A. J., Gotthelf, E. V., Burgay, Marta, Possenti, Alessia, Zane, Silvia, Coti Zelati, Francesco, Perna, Rosalba, Esposito, Paolo, Mereghetti, Sandro, Viganò, Daniele, Tiengo, Andrea, Götz, Diego, Ibrahim, A. Y., Israel, Gian Luca, Pons, José A., Sathyaprakash, R.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/262446
Acceso en línea:http://hdl.handle.net/10261/262446
Access Level:acceso abierto
Palabra clave:Stars: individual: XTE J1810-197
Stars: magnetars
Stars: neutron
X-ray bursts
Descripción
Sumario:After 15 yr, in late 2018, the magnetar XTE J1810-197 underwent a second recorded X-ray outburst event and reactivated as a radio pulsar. We initiated an X-ray monitoring campaign to follow the timing and spectral evolution of the magnetar as its flux decays using Swift, XMM-Newton, NuSTAR, and NICER observations. During the year-long campaign, the magnetar reproduced similar behaviour to that found for the first outburst, with a factor of 2 change in its spin-down rate from ∼7.2 × 10-12 to ∼1.5 × 10-11 s s-1 after two months. Unique to this outburst, we confirm the peculiar energy-dependent phase shift of the pulse profile. Following the initial outburst, the spectrum of XTE J1810-197 is well modelled by multiple blackbody components corresponding to a pair of non-concentric, hot thermal caps surrounded by a cooler one, superposed to the colder star surface. We model the energy-dependent pulse profile to constrain the viewing and surface emission geometry and find that the overall geometry of XTE J1810-197 has likely evolved relative to that found for the 2003 event.