Swift J1818. 0-1606 is a newly discovered pulsar, initially detected with Swift's BAT instrument when a short X-ray burst was observed on 2020 March 12 (GCN circular #27373). A 1. 36 s period was discovered in a follow-up observation with NICER (ATel #13551), which suggested that the source is a new magnetar. A series of subsequent radio observations, carried out at several wavelengths, have confirmed the periodic emission (ATel #13553; ATel #13554; ATel #13559; ATel #13560; ATel #13562; ATel #13575; ATel #13577; ATel #13580; ATel #13587; Esposito et al. 2020). The pulsar's rotational period derivative of 8. 16 (2) x 10^-11 implies a surface dipolar magnetic field of 3. 4 x 10¹4 G and a characteristic age of 265 years (ATel #13559). Further timing observations with NICER yielded a spin-down luminosity of 1. 1 x 10³6 erg s^-1 (ATel #13588), close to that of PSR J1119-6127, a high magnetic field rotation-powered pulsar.
Majid et al. (Tue,) studied this question.