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A powerful new approach to study early galaxy formation is through massive relic galaxies openParMRGsclosePar which are local analogs of the high-redshift red nuggets thought to represent progenitors of today.s early-type galaxies. X-ray observation of the hot diffuse gas of MRGs is the most viable means to measure the global properties like the halo concentration comma mass comma and baryon fraction comma but only two MRGs have been identified that are suitable for such an X-ray analysis. To remedy this comma we constructed a sample of MRGs to map in detail their X-ray emission. We propose a snapshot survey of the 5 MRGs in the sample which lack any X-ray data. Deep follow-up exposures with XMM-Newton and Chandra of promising targets will then be sought for detailed analysis of their mass distributions.