A New Supernova Remnant Coincident with the Slow X-Ray Pulsar AX J1845−0258

Abstract

We report on Very Large Array observations in the direction of the recently discovered slow X-ray pulsar AX J1845?0258. In the resulting images, we find a 5? shell of radio emission; the shell is linearly polarized with a nonthermal spectral index.We classify this source as a previously unidentified, young (!8000 yr) supernova remnant (SNR), G29.6?0.1, which we propose is physically associated with AX J1845?0258. The young age of G29.6?0.1 is then consistent with the interpretation that anomalous X-ray pulsars (AXPs) are isolated, highly magnetized neutron stars (“magnetars”). Three of the six known AXPs can now be associated with SNRs; we conclude that AXPs are young (?10,000 yr) objects and that they are produced in at least 5% of core-collapse supernovae.