Details

Autor(en) / Beteiligte

• Borghese, A
• Rea, N
• Turolla, R
• Rigoselli, M
• Alford, J A J
• Gotthelf, E V
• Burgay, M
• Possenti, A
• Zane, S
• Coti Zelati, F
• Perna, R
• Esposito, P
• Mereghetti, S
• Viganò, D
• Tiengo, A
• Götz, D
• Ibrahim, A
• Israel, G L
• Pons, J
• Sathyaprakash, R

Titel

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

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2021-07, Vol.504 (4), p.5244-5257

Ort / Verlag

Oxford University Press

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Electronic Journals Library

Beschreibungen/Notizen

• ABSTRACT 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.