Weighing the IMBH candidate CO-0.40-0.22* in the Galactic Centre

TL;DR

This paper investigates the nature of the IMBH candidate CO-0.40-0.22* near the Galactic Centre using models and simulations, estimating its mass and discussing its possible origins.

Contribution

It provides a lower mass limit for CO-0.40-0.22* and explores its formation scenarios, challenging previous assumptions about IMBH formation near the Galactic Centre.

Findings

Lower mass limit of a few 10^4 solar masses for CO-0.40-0.22*

Excludes in-situ formation of such massive black hole near the Galactic Centre

Suggests possible origin from dark matter halo or globular cluster

Abstract

The high velocity gradient observed in the compact cloud CO-0.40-0.22, at a projected distance of 60 pc from the centre of the Milky Way, has led its discoverers to identify the closeby mm continuum emitter, CO-0.40-0.22*, with an intermediate mass black hole (IMBH) candidate. We describe the interaction between CO-0.40-0.22 and the IMBH, by means of a simple analytical model and of hydrodynamical simulations. Through such calculation, we obtain a lower limit to the mass of CO-0.40-0.22* of few $10^4 \times \; M_{\odot}$. This result tends to exclude the formation of such massive black hole in the proximity of the Galactic Centre. On the other hand, CO-0.40-0.22* might have been brought to such distances in cosmological timescales, if it was born in a dark matter halo or globular cluster around the Milky Way.