Evidence of non-luminous matter in the center of M62

TL;DR

This study uses pulsar acceleration data in globular cluster M62 to identify a central mass excess, providing evidence for non-luminous matter possibly indicating an intermediate mass black hole or dark remnants.

Contribution

It presents the first observational evidence of a central mass excess in M62 using pulsar accelerations, constraining the nature of unseen mass in the cluster.

Findings

Detected a central mass excess of 1200-6000 solar masses.

The excess accounts for 0.2-1% of the cluster's total mass.

Cannot distinguish between an IMBH and dark stellar remnants.

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]$M_{\odot}$, corresponding to [0.2, 1] percent of the current total mass of the cluster. Our analysis can not unambiguously discriminate between an IMBH or a system of stellar mass dark remnants of comparable total mass.