DISCOVERY OF A LARGE-SCALE ABUNDANCE GRADIENT IN THE CLUSTER OF GALAXIES AWM-7 WITH ASCA

A large-scale gradient in the metal abundance has been detected with A SCA from an X-ray bright cluster of galaxies, AWM 7. The metal abundan ce shows a peak of 0.5 solar at the center and smoothly declines to le ss than or similar to 0.2 solar at a radius of 500 kpc. The gas temper ature is found to be constant at 3.8 keV. The radial distribution of i ron can be fitted with a beta model with beta similar to 0.8 assuming the same core radius (115 kpc) as that of the intracluster medium. The metal distribution in AWM 7 suggests that the gas injected from galax ies is not efficiently mixed in the cluster space and traces the distr ibution of galaxies.