The M-Sigma Project

TL;DR

The M-Sigma Project aims to refine the relationship between supermassive black hole mass and stellar velocity dispersion by re-evaluating measurement techniques and definitions using advanced spectroscopy and stellar models.

Contribution

It introduces a comprehensive approach to accurately estimate M and sigma, addressing uncertainties in previous methods and definitions.

Findings

Re-evaluated SMBH mass estimates using new spectroscopy techniques

Clarified the best way to define stellar velocity dispersion

Improved the precision of the M-Sigma relation

Abstract

There is an intimate link between supermassive black hole (SMBH) mass (M) and the stellar velocity dispersion (sigma) of the host bulge. This has a fundamental impact on our understanding of galaxy and SMBH formation and evolution. However, the scatter, slope and zero-point of the relation is a subject of some debate. For any progress to be made on this relation, the established values of M and sigma must be robust. Over 50% of current M estimates have been made using the technique of stellar dynamics. However, there is serious concern over this method that prompts their re-evaluation. In addition, it is not clear how best to define sigma. The aim of the M-Sigma Project is to use STIS long-slit spectroscopy, integral field spectroscopy and the latest stellar models, to best estimate the values of M and sigma in as many cases as possible. The project will determine the most appropriate properties of the M-Sigma relation itself.