Rotation and Mass in the Milky Way and Spiral Galaxies

TL;DR

This review discusses methods for measuring galaxy rotation curves and calculating mass distributions in the Milky Way and spiral galaxies, highlighting direct and decomposition techniques and recent observational results.

Contribution

It provides a comprehensive overview of rotation curve measurement methods and mass calculation techniques, including recent observational insights and model fitting approaches.

Findings

Rotation curves are essential for understanding galaxy mass distribution.

Decomposition method allows detailed modeling of galaxy components.

Recent observations refine mass estimates and galaxy dynamics understanding.

Abstract

[PASJ Review Paper] 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. ( Full resolution copy is available at URL: http://www.ioa.s.u-tokyo.ac.jp/~sofue/htdocs/PASJreview2016/ )