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Compact elliptical galaxies openParCEGsclosePar are local analogs of the high-redshift ..red nuggets. thought to represent progenitors of today.s early-type galaxies. CEGs comma being low-redshift comma are much more accessible to detailed observational study. Analysis of shallow Chandra observations of two well-studied CEGs in optical-IR reveals extended comma luminous hot gas halos implying massive galaxies with M200 virgul openPar5-10closePar x 10elevkeyOpen 12keyClose Msun. We propose a deep follow-up observation of one of these targets to map its gravitating mass profile out to a radius virgulr_keyOpen 2500keyClose and measure the halo concentration comma total mass comma and baryon fraction.

紧凑型椭圆星系（Compact Elliptical Galaxies, CEGs）是高红移“红色致密星系（red nuggets）”的局域对应天体，被认为是现今早型星系的前身系统。作为低红移天体的CEGs，更便于开展精细化的观测研究。对两个已被充分研究的CEGs开展的光学红外波段浅层次钱德拉（Chandra）X射线观测分析显示，这些星系存在延展且明亮的热气体晕，其M200晕质量可达(5–10)×10^12 M☉。我们提议对其中一个目标天体开展深度后续观测，以将其引力质量分布测绘至半径2500，并测定其晕浓度、总质量与重子丰度。