A Shifty Spectral Line from CCO PSR J0821-4300: Accretion From a Debris DiskquestionMark

We confirm a shifting line feature in the spectrum of PSR J08214300, thecompact central object (CCO) in Puppis A. This pulsar has the smallest dipolemagnetic field (2.8E10 G) inferred for any young neutron star. The spectralfeature is consistent with electron cyclotron resonance scattering of surfaceemitted photons in this magnetic field, however, its strength and energy areunexpectedly variable in time. We propose new measurements to monitor theimplied variability of the magnetic field, plausibly indicative of accretion ofsupernova debris, a likely mechanism for generating an emission line. Thisobservation will also allow simultaneous timing of the pulsar to test forcorrelated torque noise and to ensure a continued ephemeris to monitor its longterm timing behavior. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]