We report the detection of an extended X-ray nebulosity with an elongation from northeast to southwest in excess of 15 ^ { \prime \prime } in a radial profile and imaging of the recurrent nova T Pyx using the archival data obtained with the X-ray Multi-Mirror Mission ( XMM - Newton ) , European Photon Imaging Camera ( pn instrument ) .
The signal to noise ratio ( S/N ) in the extended emission ( above the point source and the background ) is 5.2 over the 0.3-9.0 keV energy range and 4.9 over the 0.3-1.5 keV energy range .
We calculate an absorbed X-ray flux of 2.3 \times 10 ^ { -14 } erg cm ^ { -2 } s ^ { -1 } with a luminosity of 6.0 \times 10 ^ { 32 } erg s ^ { -1 } from the remnant nova in the 0.3-10.0 keV band .
The source spectrum is not physically consistent with a blackbody emission model as a single model or a part of a two-component model fitted to the XMM - Newton data ( kT { { } _ { BB } } > 1 keV ) .
The spectrum is best described by two MEKAL plasma emission models with temperatures at 0.2 ^ { +0.7 } _ { -0.1 } keV and 1.3 ^ { +1.0 } _ { -0.4 } keV .
The neutral hydrogen column density derived from the fits is significantly more in the hotter X-ray component than the cooler one which we may be attributed to the elemental enhancement of nitrogen and oxygen in the cold material within the remnant .
The shock speed calculated from the softer X-ray component of the spectrum is 300-800 km s ^ { -1 } and is consistent with the expansion speeds of the nova remnant derived from the Hubble Space Telescope ( HST ) and ground-based optical wavelength data .
Our results suggest that the detected X-ray emission may be dominated by shock-heated gas from the nova remnant .