2D Surface Brightness Modelling of Large 2MASS Galaxies II: The Role of Classical Bulges and Pseudobulges on Galaxy Scaling Relations and its implication for Supermassive Black Hole Formation

TL;DR

This study uses detailed 2D surface brightness modeling of 119 galaxies to analyze the roles of classical bulges and pseudobulges in galaxy scaling relations and black hole formation, revealing differences in their properties and evolutionary implications.

Contribution

It provides a comprehensive analysis of bulge types in galaxy scaling relations using NIR imaging, highlighting the distinct behaviors of classical bulges and pseudobulges and their impact on black hole correlations.

Findings

Classical bulges follow the same scaling relations as ellipticals.

Pseudobulges are often outliers in these relations.

Classical bulges are more luminous than pseudobulges.

Abstract

We have generated 2D-multicomponent surface brightness (SB) modelling for 100 galaxies in the Large Galaxy Atlas (LGA) together with 19 nearby cD galaxies using the near-infrared (NIR) images from 2MASS (J, H and Ks ). Our final sample of 119 galaxies includes cD galaxies, Virgo cluster galaxies, group galaxies, and field galaxies. We revisited known scaling relations (SRs) involving structural parameters, as well as those involving supermassive black holes (SMBHs) and ultramassive black holes (UMBHs). Refining the SRs, we also revisited the bulge classification and considered the Fundamental Plane (FP) and its projections, as well as other SRs, such as the colour-magnitude relation (CMR), Tully-Fisher relation (TFR) and luminosity concentration relation (LCR). Classical bulges follow the same relations as elliptical galaxies, while pseudobulges are usually outliers. The NIR colours of classical bulges and pseudobulges indicate that their ages are not radically different despite their spread in luminosity, but we noticed that classical bulges are more luminous than pseudobulges, therefore, this property provides a complementary bulge classification criterion. We included pseudobulges from other studies to strengthen the tendencies seen for pseudobulges in our sample. From the SRs for BHs, we found that pseudobulges do not follow SRs for early-type galaxies and classical bulges. Additionally, the lack of correlation between BHs and discs may indicate these structures have not coevolved. From the revision of SRs, we present a sample of galaxies likely to host SMBHs or UMBHs, which are suitable for dynamical BH mass determination from the ground.