XMM-Newton observations of the Mouse, SLX 1744-299 and SLX 1744-300

We observed the radio and X-ray source G359.23-0.82, also known as "the Mouse", with XMM-Newton. The X-ray image of this object shows a point-like source at the Mouse's "head", accompanied by a "tail" that extends for about 40″ westward. The morphology is consistent with that observed recently with Chandra [Gaensler, B.M., van der Swaluw, E., Camilo, F., et al. The Mouse that soared: high resolution X-ray imaging of the pulsar-powered bow shock G359.23-0.82, ApJ 616, 383-402, 2004]. The spectrum of the head can be described by a power-law model with a photon index Γ ≃ 1.9. These results confirm that the Mouse is a bow-shock pulsar wind nebula (PWN) powered by PSR J1747-2958. We found that the hydrogen column density toward the Mouse, N _H = (2.60 ± 0.09) × 10 ²² cm ^-2 , is 20%-40% lower than those toward two serendipitously detected X-ray bursters, SLX 1744-299 and SLX 1744-300. At a plausible distance of 5 kpc, the X-ray luminosity of the Mouse, L(0.5-10 keV) = 3.7 × 10 ³⁴ erg s ^-1 , is 1.5% of the pulsar's spin-down luminosity. We detected a Type I X-ray burst from SLX 1744-300 and found a possible decrease of N _H and persistent luminosity for this source, in comparison with those observed with ROSAT in 1992.