We present a Chandra X-ray observation of G12.82 { - } 0.02 , a shell-like radio supernova remnant coincident with the TeV gamma-ray source HESS J1813 - 178 .
We resolve the X-ray emission from the co-located ASCA source into a compact object surrounded by structured diffuse emission that fills the interior of the radio shell .
The morphology of the diffuse emission strongly resembles that of a pulsar wind nebula .
The spectrum of the compact source is well-characterized by a power-law with index \Gamma \approx 1.3 , typical of young and energetic rotation-powered pulsars .
For a distance of 4.5 kpc , consistent with the X-ray absorption , the 2–10 keV X-ray luminosity of the putative pulsar and nebula is L _ { PSR } = 3.2 \times 10 ^ { 33 } erg s ^ { -1 } and L _ { PWN } = 1.4 \times 10 ^ { 34 } erg s ^ { -1 } , respectively .
Both the flux ratio of L _ { PWN } / L _ { PSR } = 4.3 and the total luminosity of this system imply a pulsar spin-down power of \dot { E } > 10 ^ { 37 } erg s ^ { -1 } , on a par with the top ten most energetic young pulsars in the Galaxy .
We associate the putative pulsar with the radio remnant and the TeV source and discuss the origin of the \gamma -ray emission .