4U 0142+61 is one of a small class of persistently bright magnetars. Here we report on a monitoring campaign of 4U 0142+61 from 2011 July 26 - 2016 June 12 using the Swift X-ray Telescope, continuing a 16 year timing campaign with the Rossi X-ray Timing Explorer. We show that 4U 0142+61 had two radiatively loud timing events, on 2011 July 29 and 2015 February 28, both with short soft gamma-ray bursts, and a long-lived flux decay associated with each case. We show that the 2015 timing event resulted in a net spin-down of the pulsar due to over-recovery of a glitch. We compare this timing event to previous such events in other high-magnetic-field pulsars, and discuss net spin-down glitches now seen in several young, high-B pulsars.
@article{arxiv.1611.09782,
title = {Swift observations of two outbursts from the magnetar 4U 0142+61},
author = {R. F. Archibald and V. M. Kaspi and P. Scholz and A. P. Beardmore and N. Gehrels and J. A. Kennea},
journal= {arXiv preprint arXiv:1611.09782},
year = {2017}
}