Mapping the X-ray-emitting ejecta in Cassiopeia A with Chandra

We present X-ray emission-line equivalent width images of the bright Galact ic supernova remnant Cassiopeia A for the elements Si, S, Ar, Ca, and Fe us ing a 50,000 s observation with the Advanced CCD Imaging Spectrometer on th e Chandra X-Ray Observatory. The images essentially map the bulk of detecta ble ejecta of these elements over a wide range of surface brightnesses and show morphologies distinctly different from that of the broadband X-ray emi ssion and the 4-6 keV continuum emission. The Si, S, Ar, and Ca maps, while different in turn from those of Fe, are similar to the distribution of fas t optical ejecta knots in that they clearly delineate the X-ray counterpart of the northeast optical jet. Low surface brightness regions just outside the bright shell in the north and west are also shown to have strong line e mission. The strong Fe emission is exterior to that of other elements in th e east, as previously noted, but is generally coincident elsewhere. The pro jected interior has relatively little emission traced by high line equivale nt widths.