ASCA DETECTION OF IRON LINE EMISSION FROM THE DISTANT GALAXY CLUSTER ABELL-370

ASCA observations of the gravitational lens and Butcher-Oemler cluster Abell 370 (z = 0.37) give kT = 8.8 +/- 0.8 keV and A = 0.5 +/- 0.1 co smic. If the gas were isothermal the implied cluster mass would be M(v ir) = (1.5 +/- 0.4) x 10(15)M., a, value consistent with the optically -determindd virial mass. We detect iron K line emission with high conf idence. This measurement increases, by a large factor, the lookback ti me at which the presence of iron in the intracluster medium has been e stablished. The iron abundance is marginally higher than that of low-r edshift clusters of similar temperature, so our results are consistent with models in which all enrichment occurs before the epoch correspon ding to z = 0.37.