X-ray emission from the double pulsar system J0737-3039

We report on a 10 ks observation of the double pulsar system J0737 - 3039 obtained with the Chandra X-Ray Observatory's Advanced CCD Imaging Spectrometer. We detect the system as a point source with coordinates (J2000.0) R.A. = 07(h)37(m)51(s).23, decl. = - 30degrees39'40."9, making this the first double neutron star system to be detected at X-ray energies. Only 77 source counts are detected. The data are represented satisfactorily by a power-law spectrum with photon index Gamma = 2.9 +/- 0.4. The inferred 0.2 - 10 keV luminosity is approximate to2 x 10(30) ergs s(-1) for a distance of 0.5 kpc. We do not detect any significant variability with orbital phase in these data, which span one full orbit. These results are consistent with the X-ray emission originating solely from the magnetosphere of the energetic A pulsar, with an efficiency for conversion of rotational energy to X-rays in this band of similar to 0.04%, although we cannot exclude other possibilities