RESOLVING THE SOURCE OF X-RAYS IN THE LOCAL GROUP DWARF IC-1613 - X-RAY, RADIO, AND OPTICAL OBSERVATIONS OF A LUMINOUS SUPERNOVA REMNANT

A high-resolution X-ray image of the Local Group dwarf IC 1613 reveals that the principal source of X-ray emission in this direction arises in a background cluster of galaxies, as first suggested by Eskridge. I n addition, however, we find a bright X-ray source coincident with the only known supernova remnant in this galaxy, S8. Extensive ground-bas ed follow-up observations in the radio and optical regimes are reporte d. We confirm the nonthermal radio spectral index of the source and me asure its extent to be similar to 3 '' at 20 cm. Imaging spectrophotom etric observations taken with the multipupil spectrograph of the Speci al Astrophysical Observatory allow us to determine the density and vel ocity distribution of the gas in the remnant. The simultaneous presenc e of luminous X-ray and optical emission suggests a relatively young r emnant in which the outward-moving shock has recently encountered dens e material. We note that many of this object's properties are similar to those of the brightest optical remnant in the Large Magellanic Clou d, N49.