Answers are grounded in this paper and cite their sources.
We present the results of a kinematic survey of the dwarf spheroidal satellite of M31, And IX, which appears to be the lowest surface brightness and also the faintest galaxy ( M V = -8.3) found to date. Using Keck DEIMOS spectroscopic data, we have measured its velocity relative to M31, its velocity dispersion, and its metallicity. It exhibits a significant velocity dispersion σ v = 6.8 km s -1 , which coupled with the low luminosity implies a very high mass-to- V -band light ratio, M / L ~ 93 M ☉ / L ☉ ( M / L > 17 M ☉ / L ☉ at 99% confidence). Unless strong tidal forces have perturbed this system, this smallest of galaxies is a highly dark matter-dominated system.
No takes yet. Share an insight, caveat, or question.
Chapman et al. (2005) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: