Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-30902
Agertz, O; Lake, G; Teyssier, R; Moore, B; Mayer, L; Romeo, A B (2009). Large-scale galactic turbulence: can self-gravity drive the observed H i velocity dispersions? Monthly Notices of the Royal Astronomical Society, 392(1):294-308.
PDF (Accepted manuscript, Version 2)
View at publisher
PDF (Accepted manuscript, Version 1)
Observations of turbulent velocity dispersions in the H i component of galactic discs show a characteristic floor in galaxies with low star formation rates and within individual galaxies the dispersion profiles decline with radius. We carry out several high-resolution adaptive mesh simulations of gaseous discs embedded within dark matter haloes to explore the roles of cooling, star formation, feedback, shearing motions and baryon fraction in driving turbulent motions. In all simulations the disc slowly cools until gravitational and thermal instabilities give rise to a multiphase medium in which a large population of dense self-gravitating cold clouds are embedded within a warm gaseous phase that forms through shock heating. The diffuse gas is highly turbulent and is an outcome of large-scale driving of global non-axisymmetric modes as well as cloud–cloud tidal interactions and merging. At low star formation rates these processes alone can explain the observed H i velocity dispersion profiles and the characteristic value of ∼10 km s−1 observed within a wide range of disc galaxies. Supernovae feedback creates a significant hot gaseous phase and is an important driver of turbulence in galaxies with a star formation rate per unit area ≳10−3 M⊙ yr−1 kpc−2 .
83 downloads since deposited on 26 Feb 2010
67 downloads since 12 months
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||07 Faculty of Science > Institute for Computational Science|
|Uncontrolled Keywords:||hydrodynamics; turbulence; galaxies: evolution; galaxies: formation; galaxies: general|
|Deposited On:||26 Feb 2010 12:44|
|Last Modified:||27 Nov 2013 19:44|
|Additional Information:||The definitive version is available at www.blackwell-synergy.com|
Users (please log in): suggest update or correction for this item
Repository Staff Only: item control page