The influence of cool galaxy cluster cores on the X-ray
luminosity--gravitational mass relation is studied with Chandra observations of
64 clusters in the HIFLUGCS sample. As preliminary results we find (i) a
significant offset of cool core (CC) clusters to the high luminosity (or low
mass) side compared to non-cool core (NCC) clusters, (ii) a smaller scatter of
CC clusters compared to NCC clusters, (iii) a decreasing fraction of CC
clusters with increasing cluster mass, (iv) a reduced scatter in the
luminosity--mass relation for the entire sample if the luminosity is scaled
properly with the central entropy. The implications of these results on the
intrinsic scatter are discussed.Comment: 6 pages; to appear in the proceedings of the conference Heating vs.
Cooling in Galaxies and Clusters of Galaxies, edited by H. Boehringer, P.
Schuecker, G.W. Pratt, and A. Finoguenov. Dedicated to the memory of Peter
Schuecke