An outburst of more than 80 individual bursts , similar to those seen from Soft Gamma Repeaters ( SGRs ) , was detected from the Anomalous X-ray Pulsar ( AXP ) 1E 2259 + 586 in 2002 June .
Coincident with this burst activity were gross changes in the pulsed flux , persistent flux , energy spectrum , pulse profile and spin down of the underlying X-ray source .
We present Rossi X-ray Timing Explorer and X-ray Multi-Mirror Mission observations of 1E 2259 + 586 that show the evolution of the aforementioned source parameters during and following this episode and identify recovery time scales for each .
Specifically , we observe an X-ray flux increase ( pulsed and phase-averaged ) by more than an order of magnitude having two distinct components .
The first component is linked to the burst activity and decays within \sim 2 days during which the energy spectrum is considerably harder than during the quiescent state of the source .
The second component decays over the year following the glitch according to a power law in time with an exponent -0.22 \pm 0.01 .
The pulsed fraction decreased initially to \sim 15 % RMS , but recovered rapidly to the pre-outburst level of \sim 23 % within the first three days .
The pulse profile changed significantly during the outburst , and recovered almost fully within two months of the outburst .
A glitch of size \Delta \nu _ { max } / \nu = ( 4.24 \pm 0.11 ) \times 10 ^ { -6 } was observed in 1E 2259 + 586 that preceded the observed burst activity .
The glitch could not be well fit with a simple partial exponential recovery .
An exponential rise of \sim 20 % of the frequency jump with a time scale of \sim 14 days results in a significantly better fit to the data , however contamination from a systematic drift in the phase of the pulse profile can not be excluded .
A fraction of the glitch ( \sim 19 % ) recovered in a quasi-exponential manner having a recovery time scale of \sim 16 days .
The long-term post-glitch spin-down rate decreased in magnitude relative to the pre-glitch value .
The changes in the source properties of 1E 2259 + 586 during its 2002 outburst are shown to be qualitatively similar to changes seen during/following burst activity in two SGRs , thus further solidifying the common nature of SGRs and AXPs as magnetars .
The changes in persistent emission properties of 1E 2259 + 586 suggest that the star underwent a plastic deformation of the crust that simultaneously impacted the superfluid interior ( crustal and possibly core superfluid ) and the magnetosphere .
Finally , the changes in persistent emission properties coincident with burst activity in 1E 2259 + 586 enabled us to infer previous burst active episodes from this and other AXPs .
The non-detection of these outbursts by all-sky gamma-ray instruments suggests that the number of active magnetar candidates in our Galaxy is larger than previously thought .