[ITAL]Chandra[/ITAL] Analysis of A496: No Chemical Gradients across Cold Fronts

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Abstract
We present the results of a spatially resolved spectroscopic analysis of the galaxy cluster A496 with the S3 chip on board the Chandra satellite. We confirm the presence of a central positive temperature gradient consistent with a cooling flow but with a minimum gas temperature of ~0.5-0.9 keV. The cluster also exhibits sharp edges in gas density and temperature that are consistent with "cold front" substructures. The iron abundance profile is not radially symmetric relative to the cluster center. Toward the direction of the most prominent (northerly) cold front, the iron abundance is roughly flat, with nearly solar values. In the opposite (southerly) direction from the center, the iron abundance distribution shows an "off-center" peak. Various abundance ratios suggest that the heavy elements in the central regions of the cluster are dominated by Type Ia supernova (SN Ia) ejecta. However, for radii greater than 100 h kpc, the abundance ratios vary in such a way that different abundance ratios provide very different estimates of the proportion of SN Ia/II ejecta. Nonetheless, observed abundances and abundance ratios are continuous across the cold fronts, which suggests that the cold fronts are not likely to be the result of a subcluster merger. We suggest instead that the cold fronts in A496 are caused by "sloshing" of the central cooling flow gas, induced by the motion of the cD galaxy about the cluster center.
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