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Session 74 - Supernova Remnants.
Display session, Thursday, June 13
Great Hall,

[74.02] The Discovery of Localized Hard X-ray Emission in the Supernova Remnant IC 443

J. W. Keohane (NASA/GSFC and U. Minnesota), E. V. Gotthelf, R. Petre (NASA/GSFC), M. Ozaki, K. Koyama (Kyoto Univ.)

We present ASCA GIS data that show a hard X-ray source located at 06^h 17^m 05^s,+22\deg 21\arcmin 30\arcsec (J2000), which is on the southern shell of the supernova remnant IC 443 \@. We also present ROSAT HRI data which show emission of approximately 1\arcmin\ in extent and no strong periodicity from 0.1 to 1000 Hz\@. The ASCA spectrum of this feature can be characterized by a power-law of energy spectral index \alpha = 1.5 \pm 0.3\@. The hard source is coincident with a unique region of flat radio spectral index (\alpha < 0.24). Linking the radio and X-ray spectra yields an upper limit of 10^16 Hz on the break frequency\@.

The source is near a region of known interactions between shocks and molecular clouds. Moreover, the hard source lies on the 99% confidence error circle of the gamma ray source 2EG J0618+2234\@. However, the Digitized Sky Survey and the VLA D Array Sky Survey show no obvious optical nor radio counterparts. From the current data, we conclude that this source is most likely a site of ongoing particle acceleration producing X-ray synchrotron radiation.

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