Star formation and feedback in smoothed particle hydrodynamic simulations – I. Isolated galaxies

Abstract

We present an analysis of star formation and feedback recipes appropriate for galactic smoothed particle hydrodynamics simulations. Using an isolated Milky Way-like galaxy, we constrain these recipes based on well-established observational results. Our star formation recipe is based on that of Katz with the additional inclusion of physically motivated supernova feedback recipes. We propose a new feedback recipe in which Type II supernovae are modelled using an analytical treatment of blastwaves. With this feedback mechanism and a tuning of other star formation parameters, the star formation in our isolated Milky Way-like galaxy follows the slope and normalization of the observed Schmidt law. In addition, we reproduce the lowdensity cut-off and filamentary structure of star formation observed in disc galaxies. Our final recipe will enable better comparison of N-body simulations with observations.

The distribution of mass components in simulated disc galaxies

“…Stars feed energy and metals to the surrounding interstellar medium. Energy feedback by supernovae is implemented by means of the blastwave formalism (Stinson et al 2006) where SN × 10 51 erg of thermal energy is released. The amount of metals deposited from SNe explosions is computed from a Chabrier IMF, and they diffuse between gas particles as described in Shen et al (2010).…”

“…Progress was made by implementing increasingly effective recipes for feedback from supernovae (Thacker & Couchman 2001;Stinson et al 2006) and the inclusion of other forms of feedback from massive stars Hopkins et al 2014). The benchmark for assessing this progress has primarily been the ability to match the Tully-Fisher relation (e.g.…”

Evaluating galactic habitability using high-resolution cosmological simulations of galaxy formation

“…These processes result in clumpy and disky galaxies whose anisotropic shapes are only now beginning to be captured by the latest hydrodynamic cosmological simulations (e.g. Stinson et al 2006;Libeskind et al 2010;Kobayashi & Nakasato 2011;Knebe et al 2011;Pilkington et al 2012;Scannapieco et al 2012;Vogelsberger et al 2014;Graziani et al 2015).…”

The Supernova – ISM/Star-formation interplay

“…In addition, specific SN energy deposit SN × E SN /M * by them is fixed to 10 51 erg per 55 M of formed stars (1.8 × 10 49 erg M −1 by Dalla Vecchia & Schaye (2008)), but their results cannot ye tbe treated quantitatively, since they also mismatch with the Kennicutt relation. Stinson et al (2006) performed a comprehensive study about the influence of SN over a large scale of values and also of the dependence on the mass resolution of their SPH scheme GASOLINE of galaxy evolution. Although their results demonstrate the already expected trends, more realistic treatments must adapt SN self-consistently to the local state of the ISM what requires much larger numerical capacity for more intensive high-resolution numerical simulations.…”