Towards a self-consistent numerical model of late-type galaxies: Calibrating the effects of sub-grid physics on galactic models

Abstract

We carry out several isolated galaxy evolution simulations in a fixed dark matter halo gravitational potential using the new version of our N-body/smoothed particle hydrodynamics code gcd+. The new code allows us to more accurately model and follow the evolution of the gas and stellar components of the system including powerful supernovae feedback and its effects on the interstellar medium. Here we present the results of six simulations of an M33-sized late-type disc galaxy, each with varying values for our model parameters which include the star formation efficiency (C *), the energy released per supernovae explosion (E SN) and the energy released per unit time from stellar winds (E SW). We carry out both a pixel-by-pixel and radial ring analysis method for each of our galaxies comparing our results to the observed Schmidt-Kennicutt law and vertical gas velocity dispersion versus radius relation amongst others. We find that our models with a higher feedback more closely resemble the observations and that feedback plays a pivotal role in obtaining both the observed Schmidt-Kennicutt and gas velocity dispersion relations. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.