Connecting Clump Sizes in Turbulent Disk Galaxies to Instability Theory
| Autor: | Fisher, David B, Glazebrook, Karl, Abraham, Roberto G., Damjanov, Ivana, White, Heidi, Obreschkow, Danail, Basset, Robert, Bekiaris, Georgios, Wisnioski, Emily, Green, Andy, Bolatto, Alberto D. |
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| Rok vydání: | 2017 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.3847/2041-8213/aa6478 |
| Popis: | In this letter we study the mean sizes of Halpha clumps in turbulent disk galaxies relative to kinematics, gas fractions, and Toomre Q. We use 100~pc resolution HST images, IFU kinematics, and gas fractions of a sample of rare, nearby turbulent disks with properties closely matched to z~1.5-2 main-sequence galaxies (the DYNAMO sample). We find linear correlations of normalized mean clump sizes with both the gas fraction and the velocity dispersion-to-rotation velocity ratio of the host galaxy. We show that these correlations are consistent with predictions derived from a model of instabilities in a self-gravitating disk (the so-called "violent disk instability model"). We also observe, using a two-fluid model for Q, a correlation between the size of clumps and self-gravity driven unstable regions. These results are most consistent with the hypothesis that massive star forming clumps in turbulent disks are the result of instabilities in self-gravitating gas-rich disks, and therefore provide a direct connection between resolved clump sizes and this in situ mechanism. Comment: Accepted to Apj Letters |
| Databáze: | arXiv |
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