We study the effects of Supernova (SN) feedback on the formation of galaxies using hydrodynamical simulations in a Lambda-CDM cosmology. We use an extended version of the code GADGET-2 which includes chemical enrichment and energy feedback by Type II
and Type Ia SN, metal-dependent cooling and a multiphase model for the gas component. We focus on the effects of SN feedback on the star formation process, galaxy morphology, evolution of the specific angular momentum and chemical properties. We find that SN feedback plays a fundamental role in galaxy evolution, producing a self-regulated cycle for star formation, preventing the early consumption of gas and allowing disks to form at late times. The SN feedback model is able to reproduce the expected dependence on virial mass, with less massive systems being more strongly affected.
We use cosmological simulations in order to study the effects of supernova (SN) feedback on the formation of a Milky Way-type galaxy of virial mass ~10^12 M_sun/h. We analyse a set of simulations run with the code described by Scannapieco et al. (200
5, 2006), where we have tested our star formation and feedback prescription using isolated galaxy models. Here we extend this work by simulating the formation of a galaxy in its proper cosmological framework, focusing on the ability of the model to form a disk-like structure in rotational support. We find that SN feedback plays a fundamental role in the evolution of the simulated galaxy, efficiently regulating the star formation activity, pressurizing the gas and generating mass-loaded galactic winds. These processes affect several galactic properties such as final stellar mass, morphology, angular momentum, chemical properties, and final gas and baryon fractions. In particular, we find that our model is able to reproduce extended disk components with high specific angular momentum and a significant fraction of young stars. The galaxies are also found to have significant spheroids composed almost entirely of stars formed at early times. We find that most combinations of the input parameters yield disk-like components, although with different sizes and thicknesses, indicating that the code can form disks without fine-tuning the implemented physics. We also show how our model scales to smaller systems. By analysing simulations of virial masses 10^9 M_sun/h and 10^10 M_sun/h, we find that the smaller the galaxy, the stronger the SN feedback effects.
