Global stability and the mass-to-light ratio of galactic disks

D. Syer; Shude Mao; H. J. Mo

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arXiv · astro-ph/9711160

Global stability and the mass-to-light ratio of galactic disks

D. Syer·Shude Mao·H. J. Mo

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Abstract

We examine the global stability of an exponential stellar disk embedded in a dark matter halo and constrain the mass-to-light ratio of observed disks in the I-band, Y_I. Assuming only that the radial surface density distribution of disks is exponential, we derive an analytic upper limit: Y_I <~ 2.4h, for a Hubble constant of 100h~\kms\mpc^{-1}. Using N-body simulations we derive a stability criterion significantly different from that of previous authors. Using this criterion we argue that, almost independent of the concentration of the halo, Y_I <~ 1.9h. We discuss this result in relation to other independent determinations of Y_I, its limitations and its implications for theories of disk formation and barred galaxies.

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D. Syer, Shude Mao, H. J. Mo. 1997-11-14. Global stability and the mass-to-light ratio of galactic disks. https://arxiv.org/abs/astro-ph/9711160

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