EvoL: the new Padova Tree-SPH parallel code for cosmological simulations

I. Basic code: gravity and hydrodynamics

Department of Astronomy, University of Padova, Vicolo dell'Osservatorio 3, 35122 Padova, Italy e-mail: [emiliano.merlin;cesare.chiosi;umberto.buonomo;tommaso.grassi;lorenzo.piovan]@unipd.it

Received: 20 October 2009
Accepted: 22 December 2009

Abstract

Context. We present the new release of the Padova N-body code for cosmological simulations of galaxy formation and evolution, EvoL. The basic Tree + SPH code is presented and analysed, together with an overview of the software architectures.

Aims. EvoL is a flexible parallel Fortran95 code, specifically designed for simulations of cosmological structure formations on cluster, galactic and sub-galactic scales.

Methods. EvoL is a fully Lagrangian self-adaptive code, based on the classical oct-tree by Barnes & Hut (1986, Nature, 324, 446) and on the smoothed particle hydrodynamics algorithm (SPH, Lucy 1977, AJ, 82, 1013). It includes special features like adaptive softening lengths with correcting extra-terms, and modern formulations of SPH and artificial viscosity. It is designed to be run in parallel on multiple CPUs to optimise the performance and save computational time.

Results. We describe the code in detail, and present the results of a number of standard hydrodynamical tests.