The First Detection of a Collapsed Core Globular Cluster in M31
Cacciari, C.; Federici, L.; Ferraro, F. R.; Fusi Pecci, F.; Djorgovski, S.; Parmeggiani, G.; Bendinelli, O.; Weir, N.; Zavatti, F.
Italy, United States
Abstract
We report on the observations of a globular cluster (designated G105 = Bo 343) in the nearby spiral galaxy M 31, using the Hubble Space Telescope (HST). Image deconvolutions using three different methods indicate that this cluster has a density profile with the morphology characteristic of stellar systems which have undergone core collapse, i.e., a power-law density cusp near the center. This is the first such detection in a galaxy as distant as M 31. This discovery may lead to extensive future statistical studies of the globular cluster system of M 31, and thus a better understanding of its evolution.