PSR J0737−3039: Interacting Pulsars in X‐Rays1

Abstract

We present the results of a ~230 ks long X-ray observation of the relativistic double-pulsar system PSR J0737–3039 obtained with the XMM-Newton satellite in 2006 October. We confirm the detection in X-rays of pulsed emission from PSR J0737–3039A (PSR A), mostly ascribed to a soft nonthermal power-law component (Γ ~ 3.3) with a 0.2-3 keV luminosity of ~1.9 × 1030 erg s−1 (assuming a distance of 500 pc). For the first time, pulsed X-ray emission from PSR J0737–3039B (PSR B) is also detected in part of the orbit. This emission, consistent with thermal radiation with temperature kBT 30 eV and a bolometric luminosity of ~1032 erg s−1, is likely powered by heating of PSR B's surface caused by PSR A's wind. A hotter (~130 eV) and fainter (~5 × 1029 erg s−1) thermal component, probably originating from backfalling particles heating polar caps of either PSR A or PSR B, is also required by the data. No signs of X-ray emission from a bow shock between PSR A's wind and the interstellar medium or PSR B's magnetosphere are present. The upper limit on the luminosity of such a shock component (~1029 erg s−1) constrains the wind magnetization parameter σM of PSR A to values greater than 1.