A Nonthermal X-ray Supernova Remnant Toward the Galactic Center
Abstract
Recent Chandra and XMM-Newton observations reported evidence of a nonthermal X-ray filament in the Galactic center (Sakano et al. 2003, MNRAS, astro-ph 0211572). This X-ray source XMM J174540--2904.5 has a hard spectrum with an extent of 15'' and coincides with a wisp-like nonthermal radio source called E (Ho et al. 1985, ApJ, 288, 275). Here, we present more sensitive VLA and Chandra observations of XMM J174540--2904.5 and report detection of an additional wisp (F) of nonthermal X-ray emission. We show that sources E and F, each with an X-ray photon index of 1.2, coincide with the brightest portion of shell-like radio features. Ho et al. (1985) had suggested that these wisps are associated with a supernova remnant and here we confirm their interpretation. Measurement of the X-ray absorption places the shell-type SNR G359.6-0.5 at the distance of the Galactic center or beyond with NH ∼ 1.7 1023 per square cm. The coincidence of the linearly polarized emission at 2cm with nonthermal X-ray emission is compelling evidence for the acceleration of particles to TeV energies, as has been seen in SN 1006 and G347.3-0.5.
This research was supported by NASA grant NAS8-39073.- Publication:
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AAS/High Energy Astrophysics Division #7
- Pub Date:
- March 2003
- Bibcode:
- 2003HEAD....7.1001Y