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تسجيل مستخدم جديدGas Content and Kinematics in Clumpy, Turbulent Star-forming Disks
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We present molecular gas mass estimates for a sample of 13 local galaxies whose kinematic and star forming properties closely resemble those observed in $zapprox 1.5$ main-sequence galaxies. Plateau de Bure observations of the CO[1-0] emission line and Herschel Space Observatory observations of the dust emission both suggest molecular gas mass fractions of ~20%. Moreover, dust emission modeling finds $T_{dust}<$30K, suggesting a cold dust distribution compared to their high infrared luminosity. The gas mass estimates argue that $zsim$0.1 DYNAMO galaxies not only share similar kinematic properties with high-z disks, but they are also similarly rich in molecular material. Pairing the gas mass fractions with existing kinematics reveals a linear relationship between $f_{gas}$ and $sigma$/$v_{c}$, consistent with predictions from stability theory of a self-gravitating disk. It thus follows that high gas velocity dispersions are a natural consequence of large gas fractions. We also find that the systems with lowest depletion times ($sim$0.5 Gyr) have the highest ratios of $sigma$/$v_{c}$ and more pronounced clumps, even at the same high molecular gas fraction.
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