A New velocity-dispersion profile for the Core of 47Tuc

Abstract As part of an effort to identify astrometric evidence of an intermediate-mass black hole in 47Tuc, we construct a new velocity-dispersion profile for the innermost 30 ″ of the cluster using WFPC2 and WFC3 images spanning an unprecedented 22 yr time baseline. The WFPC2 exposures were processed using a deep-learning centering procedure as well as an improved astrometric calibration of the camera. The resulting velocity-dispersion profile has a 1 ″ spatial resolution and error bars that compare very favorably to prior studies.