Author ORCID Identifier

Stacy S. McGaugh

Document Type

Article

Publication Date

8-10-2008

Abstract

Using the Tuorla-Heidelberg model for the mass distribution of the Milky Way, I determine the rotation curve predicted by MOND (modified Newtonian dynamics). The result is in good agreement with the observed terminal velocities interior to the solar radius and with estimates of the Galaxy's rotation curve exterior thereto. There are no fit parameters: given the mass distribution, MOND provides a good match to the rotation curve. The Tuorla-Heidelberg model does allow for a variety of exponential scale lengths; MOND prefers short scale lengths in the range 2.0 kpc ≲ Rd ≲ 2.5 kpc. The favored value of Rd depends somewhat on the choice of interpolation function. There is some preference for the "simple" interpolation function as found by Famaey & Binney. I introduce an interpolation function that shares the advantages of the simple function on galaxy scales while having a much smaller impact in the solar system. I also solve the inverse problem, inferring the surface mass density distribution of the Milky Way from the terminal velocities. The result is a Galaxy with "bumps and wiggles" in both its luminosity profile and rotation curve that are reminiscent of those frequently observed in external galaxies. © 2008. The American Astronomical Society. All rights reserved.

Keywords

dark matter, galaxies: kinematics and dynamics, galaxies: spiral

Language

English

Publication Title

Astrophysical Journal

Grant

505956

Rights

© The American Astronomical Society. All rights reserved. This content is free to access, download, and share. For all other uses, you must obtain permission to reuse content: https://journals.aas.org/article-charges-and-copyright/#AAS_material

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