The Intrinsic Ellipticity of Spiral Disks
Abstract
We have measured the distribution of intrinsic ellipticities for a sample of 28 relatively face-on spiral disks. We combine H-alpha velocity fields and R and I-band images to determine differences between kinematic and photometric inclination and position angles, from which we estimate intrinsic ellipticities of galaxy disks. Our findings suggest disks have a log-normal distribution of ellipticities (mean epsilon =0.06) and span a range from epsilon= 0 (circular) to epsilon=0.2. We are also able to construct a tight Tully-Fisher relation for our face-on sample. We use this to assess the contribution of disk ellipticity on the observed Tully-Fisher scatter.
Keywords
Cite
@article{arxiv.astro-ph/0201406,
title = {The Intrinsic Ellipticity of Spiral Disks},
author = {David R. Andersen and Matthew A. Bershady},
journal= {arXiv preprint arXiv:astro-ph/0201406},
year = {2007}
}
Comments
4 pages, 2 figures, to appear in "Disks of Galaxies: Kinematics, Dynamics and Perturbations" (ASP Conference Series), eds E.Athanassoula and A. Bosma