Author ORCID Identifier

Stacy S. McGaugh

Document Type

Article

Publication Date

2-24-2009

Abstract

We model the Navarro-Frenk-White (NFW) potential to determine if, and under what conditions, the NFW halo appears consistent with the observed velocity fields of low surface brightness (LSB) galaxies. We present mock DensePak Integral Field Unit (IFU) velocity fields and rotation curves of axisymmetric and nonaxisymmetric potentials that are well matched to the spatial resolution and velocity range of our sample galaxies. We find that the DensePak IFU can accurately reconstruct the velocity field produced by an axisymmetric NFW potential and that a tilted-ring fitting program can successfully recover the corresponding NFW rotation curve. We also find that nonaxisymmetric potentials with fixed axis ratios change only the normalization of the mock velocity fields and rotation curves and not their shape. The shape of the modeled NFW rotation curves does not reproduce the data: these potentials are unable to simultaneously bring the mock data at both small and large radii into agreement with observations. Indeed, to match the slow rise of LSB galaxy rotation curves, a specific viewing angle of the nonaxisymmetric potential is required. For each of the simulated LSB galaxies, the observer's line of sight must be along the minor axis of the potential, an arrangement that is inconsistent with a random distribution of halo orientations on the sky. © 2009. The American Astronomical Society. All rights reserved.

Keywords

dark matter, galaxies: kinematics and dynamics

Language

English

Publication Title

Astrophysical Journal

Grant

702496

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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