Supernovae generated High Velocity Compact Clouds

TL;DR

This paper proposes that supernovae, rather than intermediate mass black holes, can produce high velocity compact molecular clouds, explaining observations without thermal emission and suggesting a common formation mechanism.

Contribution

The study introduces a supernova-based model for high velocity clouds, challenging the black hole hypothesis and accounting for observed properties and lack of thermal emission.

Findings

Supernovae can generate high velocity compact clouds with low thermal emission.

The model explains the kinetic energy and density of observed clouds.

Implications for the population of intermediate mass black holes in galactic centers.

Abstract

It has been proposed that an intermediate mass black hole can produce compact molecular clouds with large velocity dispersions. This model is called into question due to the discovery of several such short lived clouds, which suggests they are common, and hence it is unlikely that their formation involves an exotic object such as an intermediate mass black hole. In this paper we propose an alternative model, where supernovae produce such clouds. We apply our model to a such a cloud called CO-0.40-0.22. A previous work pointed out the fact that the kinetic energy of this cloud is comparable to that from a supernova, but disqualified the supernova scenario due to lack of thermal emission. We explain the lack of thermal emission as a consequence of the large density of the medium. In such a medium, the supernova shock is radiation dominated, and hence the initial temperatures are lower by many orders of magnitude compared with a typical supernova. Finally, we discuss some of the consequences of having a significant population of intermediate mass black holes in the galactic centre.