Halo millisecond pulsars ejected by intermediate mass black holes in globular clusters

TL;DR

This paper investigates how intermediate mass black holes in globular clusters could eject millisecond pulsars at high velocities, providing an indirect method to detect these elusive black holes through radio observations.

Contribution

It models the dynamical interactions leading to ejected fast millisecond pulsars as evidence for intermediate mass black holes in globular clusters.

Findings

Ejected MSPs can reach high velocities detectable in the Galactic halo.

The population of halo MSPs can serve as indirect evidence for IMBHs.

Detection prospects are promising with upcoming radio surveys.

Abstract

Intermediate mass black holes (IMBHs) are among the most elusive objects in contemporary astrophysics. Both theoretical and observational evidence of their existence is subject of debate. Conversely, both theory and observations confirm the presence of a large population of millisecond pulsars (MSPs) with low mass companions residing in globular cluster (GC) centers. If IMBHs are common in GC centers as well, then dynamical interactions will inevitably break up many of these binaries, causing the ejection of several fast MSPs in the Galactic halo. Such population of fast halo MSPs, hard to produce with 'standard' MSP generation mechanisms, would provide a strong, albeit indirect, evidence of the presence of a substantial population of IMBHs in GCs. In this paper we study in detail the dynamical formation and evolution of such fast MSPs population, highlighting the relevant observational properties and assessing detection prospects with forthcoming radio surveys.