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| Paper: |
The Stability of Galaxy Disks |
| Volume: |
480, Structure and Dynamics of Disk Galaxies |
| Page: |
93 |
| Authors: |
Westfall, K. B.; Andersen, D. R.; Bershady, M. A.; Martinsson, T. P. K.; Swaters, R. A.; Verheijen, M. A. W. |
| Abstract: |
We calculate the stellar surface mass density (Σ*) and two-component
(gas+stars) disk stability (QRW) for 25 late-type galaxies from the
DiskMass Survey. These calculations are based on fits of a dynamical model to
our ionized-gas and stellar kinematic data performed using a Markov Chain Monte
Carlo sampling of the Bayesian posterior. Marginalizing over all galaxies, we
find a median value of QRW = 2.0±0.9 at 1.5 scale lengths. We also find that
QRW is anti-correlated with the star-formation rate surface density
(Σ*), which can be predicted using a closed set of empirical scaling
relations. Finally, we find that the star-formation efficiency
(Σ*/Σg) is correlated with Σ* and weakly anti-correlated
with QRW. The former is consistent with an equilibrium prediction of
Σ*/Σg ∝ Σ*1/2. Despite its order-of-magnitude
range, we find no correlation of Σ*/ΣgΣ*1/2 with any
other physical quantity derived by our study. |
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