Update on the spin-down rate of Swift J1555.2-5402
ATel #14685; G. L. Israel (INAF-OAR) , F. Coti Zelati, A. Borghese, R. Sathyaprakash, N. Rea (ICE-CSIC), M. Imbrogno (INAF-OAR), P. Esposito (IUSS Pavia), S. Campana (INAF-OAB), M Burgay, A. Possenti, M. Pilia (INAF-OAC) on behalf of a larger collaboration
on 8 Jun 2021; 03:48 UT
Distributed as an Instant Email Notice Transients
Credential Certification: GianLuca Israel (gianluca@mporzio.astro.it)
Subjects: X-ray, Neutron Star, Soft Gamma-ray Repeater, Transient, Pulsar, Magnetar
Swift/XRT observed the new magnetar on June 7th, 2021, while operating in WT mode, for ~1.9 ks of effective exposure time. Here below, we provide a refined timing solution for the source based on the latter dataset, also including an updated time correction for the NICER data and an updated NuSTAR dataset (Israel et al., ATEL #14679).
We derived the following best timing solution for the initial phases of the outburst: period P = 3.861012(2) s and period derivative Pdot = (2.9+/-0.8)E-11 s/s (reference epoch T0 = 59368.0 MJD; the uncertainties in parenthesis are at 1 sigma). This solution is consistent with that reported in ATEL #14679 within 1.6sigma and fully consistent with that of ATel #14684 (Ng et al.).
