Upper limits on the mass of supermassive black holes from STIS archival data

TL;DR

This study aims to establish upper limits on supermassive black hole masses in nearby galaxies by analyzing archival HST spectra, enhancing statistical understanding of SMBH demographics.

Contribution

It introduces a systematic method to estimate SMBH upper mass limits across a broad galaxy sample using archival spectral data.

Findings

Preliminary results for 76 galaxy bulges.

Methodology for deriving SMBH upper limits from emission-line widths.

Potential to improve SMBH mass statistics in diverse galaxy types.

Abstract

The growth of supermassive black holes (SMBHs) appears to be closely linked with the formation of spheroids. There is a pressing need to acquire better statistics on SMBH masses, since the existing samples are preferentially weighted toward early-type galaxies with very massive SMBHs. With this motivation we started a project aimed at measuring upper limits on the mass of the SMBHs that can be present in the center of all the nearby galaxies (D<100 Mpc) for which STIS/G750M spectra are available in the HST archive. These upper limits will be derived by modeling the central emission-line widths ([NII], Halpha and [SII]) observed over an aperture of ~0.1" (R<50 pc). Here we present our preliminary results for a subsample of 76 bulges.