Unusual glitch activity in the RRAT J1819-1458: An exhausted magnetar?

We present an analysis of regular timing observations of the high magnetic field Rotating Radio Transient (RRAT) J1819-1458 obtained using the 64-m Parkes and 76-m Lovell radio telescopes over the past 5 years. During this time, the RRAT has suffered two significant glitches with fractional frequency changes of 0.6 × 10^-6 and 0.1 × 10^-6. Glitches of this magnitude are a phenomenon displayed by both radio pulsars and magnetars. However, the behaviour of J1819-1458 following these glitches is quite different to that which follows glitches in other neutron stars, since the glitch activity resulted in a significant long-term net decrease in the slow-down rate. If such glitches occur every 30 years, the spin-down rate, and by inference the magnetic dipole moment, will drop to zero on a time-scale of a few thousand years. There are also significant increases in the rate of pulse detection and in the radio pulse energy immediately following the glitches.