Mass models of disk galaxies from gas dynamics

TL;DR

This paper reviews methods for constructing mass models of disk galaxies using gas dynamics, focusing on deriving rotation curves from emission-line data and calculating gravitational fields from stellar and gas mass distributions, highlighting the radial acceleration relation.

Contribution

It introduces a comprehensive overview of techniques to build mass models from gas dynamics and discusses the implications of the radial acceleration relation for galaxy mass distribution understanding.

Findings

Rotation curves derived from 3D emission-line data are crucial.

The radial acceleration relation links observed acceleration to baryonic mass.

Uncertain placement of dwarf spheroidals on the RAR is discussed.

Abstract

I review methods and techniques to build mass models of disk galaxies from gas dynamics. I focus on two key steps: (1) the derivation of rotation curves using 3D emission-line datacubes from HI, CO, and/or H-alpha observations, and (2) the calculation of the gravitational field from near-infrared images and emission-line maps, tracing the stellar and gas mass distributions, respectively. Mass models of nearby galaxies led to the establishment of the radial acceleration relation (RAR): the observed centripetal acceleration from rotation curves closely correlates with that predicted from the baryonic distribution at each galaxy radius, even when dark matter supposedly dominates the gravitational field. I conclude by discussing the (uncertain) location of Local Group dwarf spheroidal galaxies on the RAR defined by more massive disk galaxies.