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         Title: Multiphase Chemodynamical Modeling of Galaxy
        Formation and Evolution 
        Author: P. Berczik
         ABSTRACT 
          Recent
        advances in computer technology and numerical methods have allowed
        detailed modeling of baryonic matter dynamics in a universe dominated by
        collisionless dark matter and, therefore, the detailed gravitational and
        hydrodynamical description of galaxy formation and evolution. As a main
        tool for this study we use our recent Multiphase Chemodynamical Smoothed
        Particle Hydrodynamics (MP-CD-SPH) code (Berczik, Hensler, Spurzem &
        Theis, 2001, A&A, in prep.). This complex code include the
        multiphase chemodynamical model of galaxy incorporated to the effective
        3D SPH algorithm (Berczik, 1999, A&A, 
        348, 371; Berczik, 2000, A&SS, 271, 103). Our new modeling is
        include: 
          1) Two component gas description of ISM (cold
        "clouds" and "smooth" warm phase) (Samland, Hensler
        & Theis, 1997, ApJ,  476, 
        544). The basic idea is making a two component gas contents and
        added to smooth and warm SPH component some cold cloudy gas fragments.
        This cold clumps modeled as a N-body particles with some viscosity
        (Theis & Hensler, 1993, A&A, 280, 85). The cloudy component
        interact with surrounding warm SPH gas also via condensation and
        evaporation processes (Kïppen, Theis & Hensler, 1998, A&A, 331, 524).
        
         
          2)
        Original SF algorithm and description of "star" particles as a
        dynamically separate N-body particles. The cloud component phase of the
        gas is form the stars (due to cloud-cloud collisions) and after the
        stars returned to warm gas phase (due to SNII, SNIa and PN event) the
        chemically enriched gas material and energy.
        
         
          3) The code also includes the
        photometric evolution of each "star" particle, based on the
        idea of the Single Stellar Population (SSP). The SSP integrated colours
        (UBVRIKM) are taken from Tantalo, Chiosi, Bressan & Fagotto, 1996,
        A&A, {\bf 311}, 361. The spectro – photometric evolution of the
        overall ensemble of "star" particles forms the Spectral nergy
        Distribution (SED) of the galaxy. 
          As a test of our new MP--CD--SPH code, we calculate the
        star forming dwarf galaxy evolution. Because the mass of dwarf galaxies
        MGAL =108-1010 solar masses, even with
        relatively "small" number of cold "clouds" (~ 5,000
        - 10,000) give to us the needed physical resolution for realistic
        description of individual molecular clouds.  |