The Dependence of Dark Matter Halo Properties on the Morphology of Their Central Galaxies from Weak Lensing

TL;DR

This study uses weak gravitational lensing to explore how the morphology of central galaxies, characterized by the Sersic index, correlates with dark matter halo properties, revealing complex dependencies influenced by galaxy color and feedback mechanisms.

Contribution

It provides observational evidence linking galaxy morphology to halo mass and concentration, and compares these findings with hydrodynamic simulations to understand underlying physical processes.

Findings

Positive correlation between Sersic index and halo mass confirmed.

Halo concentration may also correlate with galaxy morphology.

Feedback modes in simulations influence the galaxy-halo property relationship.

Abstract

Xu \& Jing reported a monotonic relationship between host halo mass $M_h$ and the morphology of massive central galaxies, characterized by the S\'ersic index $n$, at fixed stellar mass, suggesting that morphology could serve as a good secondary proxy for halo mass. Since their results were derived using the indirect abundance matching method, we further investigate the connection between halo properties and central galaxy morphology using weak gravitational lensing. We apply galaxy-galaxy lensing to measure the excess surface density around CMASS central galaxies with stellar masses in the range of $11.3 < \log M_*/{\rm M_\odot} < 11.7$, using the HSC shear catalog processed through the Fourier\_Quad pipeline. By dividing the sample based on $n$, we confirm a positive correlation between $n$ and $M_h$, and observe a possible evidence of the positive correlation of $n$ and halo concentration. After accounting for color, we find that neither color nor morphology alone can determine halo mass, suggesting that a combination of both may serve as a better secondary proxy. In comparison to hydrodynamic simulations, we find that TNG300 produce much weaker correlations between $M_h$ and $n$. Furthermore, using SIMBA simulations with different feedback mode, we find jet-mode active galactic nuclei feedback might be related to the relationship of S\'ersic index and halo mass.