Evidence of Nonluminous Matter in the Center of M62

Abstract

Theoretical models suggest that intermediate-mass black holes (IMBHs) may form and reside in the centers of globular clusters. IMBHs are still elusive to observations, but the accelerations of pulsars may bring along a unique fingerprint of their presence. In this work, we focus on the pulsars in the globular cluster M62. Using the new distance of M62 obtained from Gaia observations, we find that the measured pulsars’ accelerations suggest a central excess of mass in the range [1200, 6000] M _⊙, corresponding to [0.2, 1]% of the current total mass of the cluster. Our analysis cannot unambiguously discriminate between an IMBH or a system of stellar mass dark remnants of comparable total mass.