Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-10-16
Astronomy and Astrophysics
Astrophysics
13 pages, 11 figures, A&A accepted
Scientific paper
10.1051/0004-6361:20078211
(Abridged) We study the effects of interstellar clouds on the dynamical and chemical evolution of gas-rich dwarf galaxies. In particular, we focus on two model galaxies similar to IZw18 and NGC1569 in comparison to models in which a smooth initial distribution of gas is assumed. We use a 2-D hydrodynamical code coupled with a series of routines able to trace the chemical products of SNeII, SNeIa and intermediate-mass stars. Clouds are simulated by adding overdense regions in the computational grid, whose locations are chosen randomly and whose density profiles match observed ones. The clouds are inherently dynamically coupled to the diffuse gas, and they experience heat conduction from a hot surrounding gas. Due to dynamical processes and thermal evaporation, the clouds survive only a few tens of Myr. Due to the additional cooling agent, the internal energy of cloudy models is typically reduced by 20 - 40% compared with models of diffuse gas alone. The clouds delay the development of large-scale outflows by mass loading, therefore helping to retain a larger amount of gas inside the galaxy. However, their bullet effect can pierce the expanding supershell and create holes through which the superbubble can vent freshly produced metals. Moreover, assuming a pristine chemical composition for the clouds, their interaction with the superbubble dilutes the gas, reducing the metallicity. The resulting final metallicity is therefore generally lower (by ~ 0.2 - 0.4 dex) than the one attained by diffuse models.
Hensler Gerhard
Recchi Simone
No associations
LandOfFree
The effect of clouds in a galactic wind on the evolution of gas-rich dwarf galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The effect of clouds in a galactic wind on the evolution of gas-rich dwarf galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The effect of clouds in a galactic wind on the evolution of gas-rich dwarf galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-714227