Discovery of Diffuse Hard X-Ray Emission from the Vicinity of PSR J1648−4611 with Suzaku

We observed the pulsar PSR J1648 4611 with Suzaku. Two X-ray sources, Suzaku J1648 4610 (Src A) and Suzaku J1648 4615 (Src B), were found in the field of view. Src A is coincident with the pulsar PSR J1648 4611, which was also detected by the Fermi Gamma-ray Space Telescope. A hard-band image indicates that Src A is spatially extended. We found point sources in the vicinity of Src A by using a Chandra image of the same region, but the point sources have soft X-ray emission, and cannot explain the hard X-ray emission of Src A. The hardband spectrum of Src A can be reproduced by a power-law model with a photon index of 2.0 0:7 . The X-ray flux in the 2–10 keV band is 1.4 10 13 erg cm 2 s . The diffuse emission suggests a pulsar wind nebula around PSR J1648 4611, but the luminosity of Src A is much larger than that expected from the spin-down luminosity of the pulsar. Parts of the very-high-energy -ray emission of HESS J1646 458 may be powered by this pulsar wind nebula driven by PSR J1648 4611. Src B has soft emission, and its X-ray spectrum can be described by a powerlaw model with a photon index of 3.0 0:8 . The X-ray flux in the 0.4–10 keV band is 6.4 10 14 erg s 1 cm . No counterpart for Src B has been found in the literature.