Will a nuclear stellar disk form in the galaxy Henize 2-10?

TL;DR

This study uses N-body simulations to predict that the galaxy Henize 2-10's young clusters will likely form a nuclear star cluster and possibly a nuclear stellar disk, with minimal influence from its central black hole.

Contribution

It demonstrates that nuclear star clusters and stellar disks may form through similar processes, even in the presence of a central massive black hole.

Findings

Formation of a nuclear star cluster with mass 4-6 million solar masses.

Potential formation of nuclear stellar disks with properties similar to observed disks.

Black hole size has limited impact on nuclear star cluster formation.

Abstract

We present results of a set of $N$-body simulations to model the future evolution of the 11 young massive clusters hosted in the central region of the dwarf starburst galaxy Henize 2-10, which contains at its center a massive black hole with a mass $M_{\rm BH} \simeq 2\times 10^6$ M$_\odot$. Nuclear star clusters are present in a great quantity of galaxies of mass similar to Henize 2-10. Our results \citep{ASCD15} show that the orbital decay and merging of the Henize 2-10 clusters will likely lead to the formation of a nuclear star cluster with mass $M_{\rm NSC} \simeq 4-6 \times 10^6$ M$_\odot$ and effective radius $r_{\rm NSC} \simeq 4.1$ pc. Additionally, we found that this mechanism can lead to the formation of disky structures with global properties similar to those of nuclear stellar disks, which reside in many "middle-weight" galaxies. This work confirms and enlarge recent results \citep{ASCDS15} that indicate how nuclear star clusters and super massive black holes are only partially correlated, since the formation process of nuclear star clusters is poorly affected by a black hole of the size of that in Henize 2-10. A new result is that nuclear star clusters and nuclear stellar disks may share the same formation path.