X-ray burst and persistent emission properties of the magnetar SGR 1830-0645 in outburst

Understand

We report on NICER X-ray monitoring of the magnetar SGR 1830-0645 covering 223 days following its October 2020 outburst, as well as Chandra and radio observations.

• We present the most accurate spin ephemerides of the source so far: $\nu=0.096008680(2)$~Hz, $\dot{\nu}=-6.2(1)\times10^{-14}$~Hz~s$^{-1}$, and a significant second and third frequency derivative terms indicative of non-negligible timing noise.
• The phase-averaged 0.8--7~keV spectrum is well fit with a double-blackbody (BB) model throughout the campaign.
• The BB temperatures remain constant at 0.46 and 1.2 keV.