The correlation of black hole mass with metallicity index of host spheroid

TL;DR

This study explores the relationship between supermassive black hole mass and metallicity indices in host spheroids, revealing a strong correlation with Mgb and a weaker one with <Fe>, which may inform galaxy evolution models.

Contribution

It provides the first detailed analysis of SMBH mass correlation with metallicity indices, highlighting the significance of Mgb over <Fe> in understanding galaxy and black hole co-evolution.

Findings

SMBH mass correlates strongly with Mgb index.

A positive but weaker correlation exists between SMBH mass and <Fe> index.

The scatter in SMBH-Mgb relation is comparable to other known relations.

Abstract

We investigate the correlation between the mass of the supermassive black holes (SMBHs) and metal abundance, using existing data sets. The SMBH mass $M_{bh}$ is well correlated with integrated stellar feature of Mgb. For 28 galaxies, the best-fit $M_{bh}$-Mgb relation has a small scatter, which is an equivalent level with other well-known relation, such as a correlation between the stellar velocity dispersion and the mass. An averaged iron index $<$Fe$>$ also positively correlates with $M_{bh}$, but the best-fit $M_{bh}$-$<$Fe$>$ relation has a larger scatter. The difference comes from the synthesis and evolution mechanisms, and may be important for the SMBH and star formation history in the host spheroid.