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 (K�ppen, 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. |