Discovery of a Pulsar Candidate Associated with the TeV Gamma-ray Source HESS J1813−178

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 Γ ≈ 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 LPSR = 3.2× 1033 erg s−1 and LPWN = 1.4× 1034 erg s−1, respectively. Both the flux ratio of LPWN/LPSR = 4.3 and the total luminosity of this system imply a pulsar spin-down power of Ė > 1037 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 γ-ray emission.