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Title

High star formation rates as the origin of turbulence in early and modern disk galaxies

Author(s)

Green, Andrew W.;  Glazebrook, Karl;  McGregor, Peter J.;  Abraham, Roberto G.;  Poole, Gregory B.;  Damjanov, Ivana;  McCarthy, Patrick J.;  Colless, Matthew;  Sharp, Robert G.

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 (1-5), with the remainder being less massive non-rotating objects (2,4,6-8). 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 (9,10). These accreting flows, however, have not been observed (11), and cosmic accretion cannot power the observed level of turbulence (12). Here we report observations of a sample of rare, highvelocity-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.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Nature, Vol. 467 (Oct 2010), pp. 684-686

Publication year

2010

Keyword(s)

Galaxies;  Star formation;  Turbulence

Publisher

Nature Publishing Group

ISSN

0028-0836

Publisher URL

http://dx.doi.org/10.1038/nature09452

Copyright

Copyright © 2010 Macmillan Publishers. The accepted manuscript is reproduced in accordance with the copyright policy of the publisher.

Additional information

This article was awarded the Louise Webster Prize for outstanding research by a scientist early in their post-doctoral career at the 2013 Astronomical Society of Australia awards. For more information, see: http://astronomy.org.au/2013/06/

Full text

Peer reviewed