A hierarchicall Friend-of-Friend algorithm to extract substructures from dark matter halos

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

Pontificia Universidad Católica, Santiago, Chile

Workshop; Supercomputing Techniques in Astrophysics; 2010

We present a substructure identification technique able to extract local overdensities from dark matter halos cosmological N-body simulation. The technique use 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 recursively the linking length parameter, decomposing each halo into a principal subhalo plus minor overdensities within. At every identification level we analyze each subhalo to remove all unbounded particles by applying an energy criterion. In this work we describe our algorithm and show some preliminar results.