Extended HI Rotation Curve and Mass Distribution of M31
Astrophysics
2010-11-11 v1
Abstract
New HI observations of Messier 31 (M31) obtained with the Effelsberg and Green Bank 100-m telescopes make it possible to measure the rotation curve of that galaxy out to ~35 kpc. Between 20 and 35 kpc, the rotation curve is nearly flat at a velocity of ~226 km/s. A model of the mass distribution shows that at the last observed velocity point, the minimum dark-to-luminous mass ratio is \~0.5 for a total mass of 3.4 10^11 Msol at R < 35 kpc. This can be compared to the estimated MW mass of 4.9 10^11 Msol for R < 50 kpc.
Cite
@article{arxiv.astro-ph/0603143,
title = {Extended HI Rotation Curve and Mass Distribution of M31},
author = {Claude Carignan and Laurent Chemin and Walter K. Huchtmeier and Felix J. Lockman},
journal= {arXiv preprint arXiv:astro-ph/0603143},
year = {2010}
}
Comments
4 pages, 2 figures, accepted for publication in ApJ Letters