2020ApJ...899..138M

We present an improved proper-motion measurement of the central compact object RX J0822-4300, located in the supernova remnant Puppis A. By employing a new data set taken in 2019 February by the High Resolution Camera on board the Chandra X-ray Observatory, we approximately double the available temporal baseline for our analysis to slightly more than 19 yr (7000 days). We correct for the astrometric inaccuracy of Chandra using calibrator stars with known optical positions that are detected in all observations. Thereby, we obtain absolute positions of RX J0822-4300 accurate to around 0′′ / . 1 and from these a new best estimate for its total proper motion of µ_tot=(80.4±7.7)masyr^–1. For a remnant distance of 2 kpc, this corresponds to a projected kick velocity of (763±73) kms^–1 at a position angle of φ₀=(247.8±4.4)^○^. The proper-motion measurement of RX J0822-4300 is used for discussing the kinematic age of Puppis A.