2012ApJ...755..141B

Using the High Resolution Camera on board the Chandra X-ray Observatory, we have re-examined the proper motion of the central compact object RX J0822-4300 in the supernova remnant Puppis A. New data from 2010 August, combined with three archival data sets from as early as 1999 December, provide a baseline of 3886 days (more than 10.5 yr) to perform the measurement. Correlating the four positions of RX J0822-4300 measured in each data set implies a projected proper motion of µ = 71±12 mas/yr. For a distance of 2 kpc, this proper motion is equivalent to a recoil velocity of 672±115 km/s. The position angle is found to be 244°±11°. Both the magnitude and direction of the proper motion are in agreement with RX J0822-4300 originating near the optical expansion center of the supernova remnant. For a displacement of 371±31 arcsec between its birthplace and today's position, we deduce an age of (5.2±1.0)x10³ yr for RX J0822-4300. The age inferred from the neutron star proper motion and filament motions can be considered as two independent measurements of the same quantity. They average to 4450 ± 750 yr for the age of the supernova remnant Puppis A.