Hierarchical Friend-of-Friend algorithm to extract substructure from dark matter halos

SGRÓ, MARIO AGUSTÍN; RUIZ, ANDRÉS NICOLÁS; MERCHÁN, MANUEL ENRIQUE

Santiago de Chile

Workshop; Supercomputing Techniques in Astronomy; 2010

Departamente de Astronomía y Astrofísica - Pontífica Universidad Católica de Chile

We present a substructure identification algorithm able to extract local overdensities from dark matter halos in a cosmological N-body simulation. We start with a standard Friend-of-Friend (FoF) algorithm to obtain the dark matter halos from a given simulation output. The subsequent peaks of increasing density are then disjoined by decreasing recursivelly the linking lenght parameter, decomposing each halo into a principal subhalo plus minor overdensities within. In every identification level we analize each subhalo to remove all unbounded particles by applying an energy criterion. In this work we describe our algorithm and show some preliminar results.