Jiaxin Han, Y. P. Jing, Huiyuan Wang, Wenting Wang
We develop a new code, the Hierarchical Bound-Tracing (HBT for short) code,
to find and trace dark matter subhalos in simulations based on the merger
hierarchy of dark matter halos. Application of this code to a recent benchmark
test of finding subhalos demonstrates that HBT stands as one of the best codes
to trace the evolution history of subhalos. The success of the code lies in its
careful treatment of the complex physical processes associated with the
evolution of subhalos and in its robust unbinding algorithm with an adaptive
source subhalo management. We keep a full record of the merger hierarchy of
halos and subhalos, and allow growth of satellite subhalos through accretion
from its subordinate subhalos in the merger hierarchy hence allowing mergers
among satellites. Local accretion of background mass is omitted while
re-accretion of stripped mass is allowed. The justification of these treatments
is provided by a case study of the life of individual subhalos and by the
success in finding the complete subhalo catalog. Dependence of this tracing
algorithm on the time resolution of simulation outputs has also been examined.
We compare our result to other popular subhalo finders and show that HBT is
able to well resolve subhalos in high density environment and keep strict
physical track of subhalos' merger history. HBT also features its fast speed as
it does not need density interpolation or spatial searching when constructing
source subhalos, and because it is fully parallelized. This code is available
upon request to the authors.
View original:
http://arxiv.org/abs/1103.2099
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