The Imprint of Spiral Arms on the Galactic Rotation Curve

Authors

Stacy S. McGaugh, Case Western Reserve UniversityFollow

Author ORCID Identifier

Stacy S. McGaugh

Document Type

Article

Publication Date

11-1-2019

Abstract

We discuss a model for the Milky Way obtained by fitting the observed terminal velocities with the radial acceleration relation. The resulting stellar surface density profile departs from a smooth exponential disk, having bumps and wiggles that correspond to massive spiral arms. These features are used to estimate the term for the logarithmic density gradient in the Jeans equation, which turn out to have exactly the right location and amplitude to reconcile the apparent discrepancy between the stellar rotation curve and that of the interstellar gas. This model also predicts a gradually declining rotation curve outside the solar circle with slope -1.7 km s-1, kpc-1, as subsequently observed.

Keywords

machine-readable tables

Language

English

Publication Title

Astrophysical Journal

Grant

1911909

Rights

© 2019. The American Astronomical Society. All rights reserved. Under https://creativecommons.org/licenses/by-nc-nd/4.0/

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.

Recommended Citation

Stacy S. McGaugh 2019. The Imprint of Spiral Arms on the Galactic Rotation Curve. ApJ 885 87