Widespread presence of shallow cusps in the surface-brightness profile of globular clusters
by Vesperini, Enrico and Trenti, Michele
14 pages, 3 figures, Accepted for publication in The Astrophysical Journal, Letters
Surface brightness profiles of globular clusters with shallow central cusps (Sigma ~ R^v with -0.3<~ v ~ -0.3 in the pre-core-collapse and core-collapse phases. Post-core-collapse clusters without an IMBH transition to steeper cusps, -0.7<~ v <~ -0.4, only if the primordial binary fraction is very small, f_{bin} -0.3 even when <~ -0.4. Overall our analysis shows that a shallow cusp is not an unequivocal signature of a central IMBH and casts serious doubts on the usefulness of measuring v in the context of the hunt for IMBHs in globular clusters.