Intrinsic Morphology of The Stellar Components in HI-bearing Dwarf Galaxies and The Dependence on Mass

TL;DR

This study investigates the intrinsic shapes of stellar components in HI-bearing dwarf galaxies, revealing they are predominantly thick, oblate-triaxial disks with minimal variation across different stellar masses.

Contribution

It introduces a novel analysis of stellar morphology in HI-bearing dwarfs using a combined MCMC and triaxial modeling approach, providing new insights into their intrinsic shapes.

Findings

Stellar components are mainly thick, oblate-triaxial disks.

Average thickness ratio C/A is approximately 0.4.

Disk thickness shows little dependence on stellar mass.

Abstract

The intrinsic morphology of stellar components within HI-bearing dwarf galaxies remains a topic of uncertainty. Leveraging the galaxy dataset derived from the cross-matched catalog of the Arecibo Legacy Fast Arecibo L-band Feed Array HI 21cm line survey and the Sloan Digital Sky Survey, we employ a Markov Chain Monte Carlo methodology and assume a triaxial model to scrutinize the inherent stellar distributions of these HI-bearing dwarf galaxies. Our analysis indicates a preference for oblate-triaxial models with $C<B\lesssim A$, indicative of thick stellar disks, characterizing the stellar components in these HI-bearing dwarfs with stellar masses ranging between $10^7\--10^{9.5}\ M_{\odot}$. The average thickness of the stellar components in HI-bearing dwarf galaxies approximates $C/A\sim 0.4$. Furthermore, we observe that the thickness of the stellar disks exhibits weak or negligible dependence on the stellar masses of HI-bearing galaxies.