Velocity Fields of Disk Galaxies

TL;DR

This paper reviews techniques for constructing and analyzing two-dimensional velocity fields of disk galaxies, emphasizing the importance of simulations to identify biases in derived rotation curves.

Contribution

It summarizes methods for creating velocity fields and advocates for simulating observations to improve accuracy in galactic studies.

Findings

New instruments provide more detailed velocity data.

Simulation of data-cubes helps reject biases.

Techniques improve understanding of galactic mass distribution.

Abstract

Two dimensional velocity fields have been an important tool for nearly 30 years and are instrumental in understanding galactic mass distributions and deviations from an ideal galactic disk. Recently a number of new instruments have started to produce more detailed velocity fields of the disks and nuclear regions of galaxies. This paper summarizes some of the underlying techniques for constructing velocity fields and deriving rotation curves. It also urges to simulate observations from the data-cube stage to reject subtle biases in derived quantities such as rotation curves.