Elliptical galaxies follow a well-known luminosity – metallicity (L − Z) relation, in the sense that more luminous ellipticals are observed to be more metal-rich than less luminous systems. Obviously this is a mass – Z relation, and its interpretation is that less massive galaxies had more significant outflows of metal-enriched gas at an early evolutionary stage. The apparent ellipticity (ϵ) had already been invoked to explain the large scatter in the L − Z relation, but Barazza & Binggeli (2002) observed that the relation between Z and ϵ in cluster dwarf elliptical galaxies (dEs) could even be stronger than the relation with mass. The idea is that outflow of metal-enriched gas preferentially occurs along the minor axis, making ϵ a critical parameter for Z in dwarfs. Here, we test this hypothesis using high-resolution N-body/SPH simulations including chemical feedback of dEs with different flattenings.

We present a comprehensive study of the gas/dust properties in UGC 12914/15 using SCUBA and CO(3–2) data from the JCMT.

We present a novel approach to accelerate astrophysical hydrodynamical simulations.We are developing a special purpose computing system for the simulation of galaxy evolution usingFieldProgrammable Gate Array (FPGA) chips as the computing engine.Together with our developed programming system, we have implemented computing pipelinesfor the Smoothed Particle Hydrodynamics (SPH) method on our PROGRAPE system.The SPH simulations using PROGRAPE is 4-11 times faster than the calculation without the board.

In this contribution, we present a new chemodynamical modelfor the early evolution history of the Milky Way withan improved chemical evolution description.Our new approach is based on the chemical evolution model by Tsujimoto et al. (1999).This description enables us to construct a detailed chemical and dynamicalmodel of halo stars in the Milky Way.Especially, we pay a special attention to a relation between chemical properties of halo stars and their kinematics.

We examine the role of primordial molecules in the Pop III to Pop II transition. We show that the critical metallicity strongly depends on H2/HD abundances and thermal history of gas. In a shock processed gas where H2 and HD are highly abundant the dependence of the critical metallicity on gas density is very steep at n ~ 100 cm-3 and T ≤ 300 K, and can become smaller than 10-6.

Our aim is to study the evolution of tidal dwarf galaxies. The firststep is to understand whether a model galaxy without Dark Matter cansustain the feedback of the ongoing star formation. We present testsof the evolution of models in which star formation efficiency,temperature threshold, initial distribution of gas and infall arevaried. We conclude that it is feasible to keep a fraction of gasbound for several hundreds of Myr and that the development of galacticwinds does not necessarily stop continuous star formation.

The evolution of the gas and dust content of the multiphase interstellar medium (ISM)is studied by modeling the chemical evolution (CE) of the Milky Way. In this model, the infall of primordial gas, stellar feedback and mass exchange between ISM phases determine the chemical evolution of the Galaxy. In comparison with one phase CE models, including multiphase ISM in CE modeling give us the advantage to account explicitly for:(1) dependence of star formation rate on fraction of cold medium;(2) studying abundance differences between ISM phases; (3) modeling the evolution of galactic dust content, as the dust destruction by SN shocks occurs in the warm medium and grain growth due to accretion in molecular clouds.