Microlensing events from galactic globular clusters

TL;DR

This paper analyzes microlensing events toward the Galactic center to identify potential lenses within globular clusters, suggesting some events may be caused by objects like brown dwarfs or stellar remnants in these clusters.

Contribution

It provides the first evidence that some microlensing events may originate from lenses in Galactic globular clusters, expanding understanding of dark matter and stellar populations.

Findings

Four microlensing events possibly caused by globular cluster lenses

Estimated lens masses suggest brown dwarfs, M-stars, or stellar remnants

Some events are highly aligned with globular cluster centers

Abstract

We present an analysis of the large set of microlensing events detected so far toward the Galactic center with the purpose of investigating whether some of the dark lenses are located in Galactic globular clusters. We find that in four cases some events might indeed be due to lenses located in the globular clusters themselves. We also give a rough estimate for the average lens mass of the events being highly aligned with Galactic globular cluster centers and find that, under reasonable assumptions, the deflectors could most probably be either brown dwarfs, M-stars or stellar remnants.