A Radiatively Quiet Glitch and Anti-glitch in the Magnetar 1E 2259+586

摘要: We report on the timing and spectral properties of soft X-ray emission from magnetar 1E 2259+586 January 2013, $\sim 8$ months after detection an anti-glitch, until September 2019, using Neil Gehrels Swift NICER observatories. During this time span, we detect two discontinuities. The first, occurring around 5 years April 2012 is a relatively large spin-up glitch with fractional amplitude $\Delta\nu/\nu=1.24(2)\times10^{-6}$. find no evidence for flux enhancement or change in pulse profile shape glitch. This consistent picture that significant number glitches are radiatively-quiet. Approximately 1.5 later exhibited anti-glitch spin-down $\Delta\nu/\nu=-5.8(1)\times10^{-7}$; similar to detected 2012. do not, however, any pulse-profile increase rms pulsed source, nor see possible bursts its direction anti-glitch; all which occurred during event. Hence, glitches, anti-glitches can occur silently. may suggest these phenomena originate neutron star interior, their locale triggering mechanism not necessarily have be connected magnetosphere. Lastly, our observations occurrence rate about same 2259+586, former having larger net change.