PASJ Review Paper, in press.

https://arxiv.org/abs/1608.08350

For a PDF version of the article, click here.

# ROTATION AND MASS IN THE MILKY WAY AND SPIRAL GALAXIES

### Yoshiaki Sofue

Institute of
Astronomy,
The
University of Tokyo, Mitaka, 181-0015 Tokyo

**Abstract:**
Rotation curves are the basic tool for deriving the distribution of mass
in spiral galaxies. In this review, we describe various methods to
measure rotation curves in the Milky Way and spiral galaxies. We then
describe two major methods to calculate the mass distribution using the
rotation curve. By the direct method, the mass is calculated from
rotation velocities without employing mass models. By the decomposition
method, the rotation curve is deconvolved into multiple mass components
by model fitting assuming a black hole, bulge, exponential disk and dark
halo. The decomposition is useful for statistical correlation analyses
among the dynamical parameters of the mass components. We also review
recent observations and derived results.

**Key words :** Galaxy: fundamental parameters -- Galaxy: kinematics
and dynamics -- Galaxy: structure
-- galaxies: fundamental parameters -- galaxies: kinematics and
dynamics -- galaxies: structure -- dark matter

**Table of Contents**

- INTRODUCTION

- ROTATION OF THE MILKY WAY
- Dynamical Parameters Representing the Galaxy
- Progress in the Galactic Rotation Curve
- Methods to Determine the Galactic Rotation Curve
- Rotation in the Galactic Center
- Logarithmic Rotation Curve: From Black Hole to
Dark Halo
- Uncertainty and Limitation of Rotation Curve
Analyses
- Radial-Velocity and Proper-Motion Fields
- Velocity-to-Space Transformation

- ROTATION CURVES OF SPIRAL GALAXIES
- Progress in Rotation Curve Studies Evidencing
for the Dark Halo
- Observations of Rotation Velocities
- Methods to Determine Rotation Velocities
- Galaxy Types and Rotation Curves
- Dark Halo: Grand Rotation Curves
- Nuclear Rotation Curves and Black Holes
- Shapes of Rotation Curves and Galaxy Types
- Statistical Properties of Rotation Curves:
Tully-Fisher Relation
- High Redshift Rotation Curves

- MASS DISTRIBUTION IN DISK GALAXIES
- Direct Mass Determination
- Rotation Curve Decomposition into Mass
Components
- Rotation Curve Decomposition in the Milky Way
- Decomposition of Galaxies' Rotation Curves

- CONCLUDING REMARKS
- Summary
- Achievements in the Decades and the Future

- REFERENCES