Extended HI disks in nearby spiral galaxies
Astrophysics of Galaxies
2017-03-29 v1
Abstract
In this short write-up, I will concentrate on a few topics of interest. In the 1970s I found very extended HI disks in galaxies such as NGC 5055 and NGC 2841, out to 2 - 2.5 times the Holmberg radius. Since these galaxies are warped, a "tilted ring model" allows rotation curves to be derived, and evidence for dark matter to be found. The evaluation of the amount of dark matter is hampered by a disk-halo degeneracy, which can possibly be broken by observations of velocity dispersions in both the MgI region and the CaII region.
Keywords
Cite
@article{arxiv.1605.09567,
title = {Extended HI disks in nearby spiral galaxies},
author = {A. Bosma},
journal= {arXiv preprint arXiv:1605.09567},
year = {2017}
}
Comments
3 pages, 2 figures, to be published in the Proceedings of IAU Symposium 321, "Formation and evolution of galaxy outskirts", Eds. A. Gil de Paz, J. C. Lee & J. H. Knapen, Cambridge University Press, Cambridge