Interstellar matter simulations


Description: Hydrodynamical evolution of the interstellar medium in galaxies is one of those topics which certainly ask for an extensive use of visualization tools. Not only the plots are truly dramatic in their appearance but their evolution over time spanning millions of years out of galaxy's life gives a unique opportunity for a better understanding of structure and dynamics of the interstellar gas, processes of stellar formation, formation and destruction of molecular clouds, or origins of galactic X-ray emission. 

In the following we study the evolution of galactic interstellar medium by means of a two-dimensional composite hydrodynamical model [ 1, 2 ] which takes into account mutual interaction between gas and stars (modelled in fluid approximation). The interaction between the two phases takes places due to stellar formation from dense and cold (molecular) gas, stellar winds which feed the medium with highly energetic gas, and supernovae being powerful although rather localized and short lived sources of the energy injection which is subsequently radiated away due to optically thin cooling of plasma. Our computational domain covers a region of 2x30 kiloparsecs, a vertical slice through the galaxy located at the distance from galactic centre similar to that of our Sun. The central region about the midplane is equally spaced in both directions (1 kpc below and above midplane); spacing in vertical direction logarithmically increases into halo to 15 kpc. 

The computation was done with help of second order explicit scheme, ZEUS-2D [ 3 ], and run in parallel mode on SGI Power Challenge supercomputer with the resolution of about 3.3 parsecs in the central (2x2 kpc) region. 

The results will help in developing the optimal strategy for numerical simulations of galactic cores and star forming regions with help of numerical schemes

This work is done in collaboration with Alex Rosen and started during the 2nd Guillermo Haro Workshop, The Physics of Star-Gas Interactions, INAOE, Mexico. 

Gas density

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This image has appeared on the front cover of  October/November 1999 issue of Scientific Computer World magazine.

Gas temperature

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gas vertical velocity

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Total gas velocity

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