X-ray observations of RX J0822-4300 and Puppis-A

Abstract

Based on observations with the X-ray observatories Chandra and XMM-Newton we present results from a detailed spectro-imaging and timing analysis of the central compact X-ray source RX J0822-4300 in the supernova remnant Puppis-A. The superior angular resolution of Chandra allows for the first time to pinpoint the point source nature of this object down to 0.59±0.01 arcsec (FWHM) and to determine its position: RA=08^h21^m57.40^s, Dec=-43°00'16.69'' (J2000) with sub-arcsecond accuracy. Spectral fits based on Chandra and XMM-Newton data provide a tight constraint on the emission properties of RX J0822-4300. Most of its X-ray emission seems to be of thermal origin. A model spectrum consisting of two blackbody components with T₁≃ 2.6×10⁶ K, T₂≃ 5.0×10⁶ K and R₁ ≃ 3.3 km, R₂ ≃ 0.75 km for the blackbody temperatures and the size of the projected emitting regions, respectively, provides the best model description of its spectrum. A search for X-ray pulsations from RX J0822-4300 revealed an interesting periodicity candidate which, if confirmed, does not support a scenario of steady spin-down.