Dissolution is the solution: on the reduced mass-to-light ratios of Galactic globular clusters

Context. The observed dynamical mass-to-light ($M/L$) ratios of globular clusters (GCs) are systematically lower than the value expected from “canonical” simple stellar population models, which do not account for dynamical effects such as the preferential loss of low-mass stars due to energy equipartition. It has recently been shown that low-mass star depletion can qualitatively explain this discrepancy for globular clusters in several galaxies. Aims. To verify whether low-mass star depletion is indeed the driving mechanism behind the $M/L$ decrease, we aim to predict the $M/L_V$ ratios of individual GCs for which orbital parameters and dynamical V-band mass-to-light ratios $M/L_V$ are known. There is a sample of 24 Galactic GCs for which this is possible. Methods. We used the SPAC