SIMBAD references

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^h37^m51{fs}23, decl.=-30°39'40".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 Γ=2.9±0.4. The inferred 0.2-10 keV luminosity is ~2x10³⁰ ergs/s 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 ∼0.04%, although we cannot exclude other possibilities.