A Multiwavelength Study of PSR J1119–6127 after 2016 Outburst

Abstract

The high magnetic field pulsar PSR J1119−6127, detected from radio to high-energy wavelengths, underwent a magnetar-like outburst beginning on 2016 July 27. In this paper, we study the postoutburst multiwavelength properties of this pulsar from the radio to GeV bands and discuss its similarity with the outburst of the magnetar XTE J1810−197. In phase-resolved spectral analysis of 0.5–10 keV X-ray data collected in 2016 August, the on- and off-pulse spectra are both characterized by two blackbody components and also require a power-law component similar to the hard X-ray spectra of magnetars. This power-law component is no longer distinguishable in data from 2016 December. We likewise find that there was no substantial shift between the radio and X-ray pulse peaks after the 2016 X-ray outburst. The gamma-ray pulsation after the X-ray outburst is confirmed with data taken after 2016 December, and the pulse structure and phase difference between the gamma-ray and radio peaks (∼0.4 cycle) are also consistent with those before the X-ray outburst. These multiwavelength observations suggest that the reconfiguration of the global magnetosphere after the 2016 magnetar-like outburst continued for at most about 6 months. We discuss the evolution of the X-ray emission after the 2016 outburst with the untwisting magnetosphere model.

Polarized X-rays from the magnetar sources

“…[28,35]), including the giant flare emitted on December 27, 2004, and it is compatible with emission of several other (not anomalous) X-ray pulsars (see e.g. [36][37][38]). This makes it reasonable to interpret the persistent emission from SGR 1806-20 within the commonly-accepted magnetar model, assuming that pulsating radiation originates from one or more hotter regions on the surface of the star which come into view at different times during the star rotation.…”

X-ray spectra and polarization from magnetar candidates

“…Magnetars are a peculiar class of neutron stars (NSs), discovered at the end of the 1970s and initially classified into two separate groups, the anomalous X-ray pulsars (AXPs) and the soft-gamma repeaters (SGRs) [1][2][3]. The former exhibit a behavior substantially similar to conventional, isolated X-ray pulsars [4][5][6], but their (persistent) X-ray luminosity exceeds the rotational energy loss rate (and for this they were dubbed "anomalous"). The latter, instead, are characterized by the repeated emission of energetic, short bursts, peaked in the hard X-, soft gamma-rays, in some cases modulated at a precise frequency, which led to the association of these sources to NSs and set them apart from short gamma-ray bursts (GRBs), with which they have been initially associated.…”

Pulsar glitches: observations and physical interpretation

“…The glitch exhibited a peculiar recovery which did not resemble the ones observed after the 2004 and 2007 glitches. This time the spin-down rate took considerable time to increase (unlike in previous glitches, where Δ ν appeared instantaneous) and there was not an obvious overshoot in ν (see figure in [295]). It was claimed that the recovery could not be fitted by an exponential function as in equation ( 15) [296] and the whole event was compared to the activity of the magnetar XTE J1810−197 [295].…”