Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-10-22
Astrophys.Space Sci. 292 (2004) 207-214
Astronomy and Astrophysics
Astrophysics
8 pages, 8 figures (in jpeg format) that include 2 simulations images and 6 plots. Paper accepted by the referee for publicati
Scientific paper
10.1023/B:ASTR.0000045019.24124.
We have carried out 1.25 pc resolution MHD simulations of the ISM, on a Cartesian grid of $0 \leq (x,y) \leq 1$ kpc size in the galactic plane and $-10 \leq z \leq 10$ kpc into the halo, thus being able to fully trace the time-dependent evolution of the galactic fountain. The simulations show that large scale gas streams emerge, driven by SN explosions, which are responsible for the formation and destruction of shocked compressed layers. The shocked gas can have densities as high as 800 cm$^{-3}$ and lifetimes up to 15 Myr. The cold gas is distributed into filaments which tend to show a preferred orientation due to the anisotropy of the flow induced by the galactic magnetic field. Ram pressure dominates the flow in the unstable branch $10^{2}<$T$\leq 10^{3.9}$ K, while for T$\leq 100$ K (stable branch) magnetic pressure takes over. Near supernovae thermal and ram pressures determine the dynamics of the flow. Up to 80% of the mass in the disk is concentrated in the thermally unstable regime $10^{2}<$T$\leq 10^{3.9}$ K with $\sim30%$ of the disk mass enclosed in the T$\leq 10^{3}$ K gas. The hot gas in contrast is controlled by the thermal pressure, since magnetic field lines are swept towards the dense compressed walls.
Breitschwerdt Dieter
de Avillez Miguel A.
No associations
LandOfFree
MHD Simulations of the ISM: The Importance of the Galactic Magnetic Field on the ISM "Phases" 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 MHD Simulations of the ISM: The Importance of the Galactic Magnetic Field on the ISM "Phases", we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and MHD Simulations of the ISM: The Importance of the Galactic Magnetic Field on the ISM "Phases" will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-664383