A CHANDRA STUDY OF SGR A EAST

Y. Maeda(Penn State) F. K. Baganoff, M. W. Bautz, J. P. Doty, G. R. Ricker (MIT), E. D. Feigelson, W. N. Brandt, D. N. Burrows, G. P. Garmire, L. K. Townsley (Penn State), M. Morris (UCLA) S. H. Pravdo (JPL)

Abstract

We report on the X-ray emission from the shell-like, non-thermal radio source Sgr A East located in the inner few parsecs of the Galaxy based on observations made with the ACIS detector on board the Chandra X-ray Observatory. This is the first time Sgr A East has been clearly resolved from other complex structures in the region. The X-ray emitting region is concentrated within the central $\simeq 2$ pc of the larger radio shell. The spectrum shows strong K$\alpha$ lines from highly ionized ions of S, Ar, Ca, and Fe. The plasma appears to be rich in heavy elements, over-abundant by roughly a factor of four with respect to solar abundances, and shows a spatial gradient of elemental abundance: the spatial distribution of iron is more compact than that of the lighter elements. The gas mass and elemental abundance of the X-ray emission support the long-standing hypothesis that Sgr A East is a supernova remnant (SNR), The relation between Sgr A East and the supermassive blackhole Sgr A* is discussed.

CATEGORY: SUPERNOVAE, SUPERNOVA REMNANTS AND ISOLATED NEUTRON STARS