High star formation rates as the origin of turbulence in early and modern disk galaxies |
| |
Authors: | Green Andrew W Glazebrook Karl McGregor Peter J Abraham Roberto G Poole Gregory B Damjanov Ivana McCarthy Patrick J Colless Matthew Sharp Robert G |
| |
Affiliation: | Centre for Astrophysics and Supercomputing, Swinburne University, PO Box 218, Hawthorn, Victoria 3122, Australia. agreen@astro.swin.edu.au |
| |
Abstract: | Observations of star formation and kinematics in early galaxies at high spatial and spectral resolution have shown that two-thirds are massive rotating disk galaxies, with the remainder being less massive non-rotating objects. The line-of-sight-averaged velocity dispersions are typically five times higher than in today's disk galaxies. This suggests that gravitationally unstable, gas-rich disks in the early Universe are fuelled by cold, dense accreting gas flowing along cosmic filaments and penetrating hot galactic gas halos. These accreting flows, however, have not been observed, and cosmic accretion cannot power the observed level of turbulence. Here we report observations of a sample of rare, high-velocity-dispersion disk galaxies in the nearby Universe where cold accretion is unlikely to drive their high star formation rates. We find that their velocity dispersions are correlated with their star formation rates, but not their masses or gas fractions, which suggests that star formation is the energetic driver of galaxy disk turbulence at all cosmic epochs. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|