HOP: A new group-finding algorithm for N-body simulations

被引:344
作者
Eisenstein, DJ [1 ]
Hut, P [1 ]
机构
[1] Inst Adv Study, Princeton, NJ 08540 USA
关键词
cosmology; theory; dark matter; methods; numerical;
D O I
10.1086/305535
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We describe a new method (HOP) for identifying groups of particles in N-body simulations. Having assigned to every particle an estimate of its local density, we associate each particle with the densest of the N-hop particles nearest to it. Repeating this process allows us to trace a path, within the particle set itself, from each particle in the direction of increasing density. The path ends when it reaches a particle that is its own densest neighbor; all particles reaching the same such particle are identified as a group. Combined with an adaptive smoothing kernel for finding the densities, this method is spatially adaptive, coordinate-free, and numerically straightforward. One can proceed to process the output by truncating groups at a particular density contour and combining groups that share a (possibly different) density contour. While the resulting algorithm has several user-chosen parameters, we show that the results are insensitive to most of these, the exception being the outer density cutoff of the groups.
引用
收藏
页码:137 / 142
页数:6
相关论文
共 15 条
[1]   ANGULAR-MOMENTUM FROM TIDAL TORQUES [J].
BARNES, J ;
EFSTATHIOU, G .
ASTROPHYSICAL JOURNAL, 1987, 319 (02) :575-600
[2]   MINIMAL SPANNING-TREES, FILAMENTS AND GALAXY CLUSTERING [J].
BARROW, JD ;
BHAVSAR, SP ;
SONODA, DH .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1985, 216 (01) :17-35
[3]  
Bertschinger E., 1991, Computers in Physics, V5, P164
[4]   The superiority of the minimal spanning tree in percolation analyses of cosmological data sets [J].
Bhavsar, SP ;
Splinter, RJ .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1996, 282 (04) :1461-1466
[5]   EXCURSION SET MASS FUNCTIONS FOR HIERARCHICAL GAUSSIAN FLUCTUATIONS [J].
BOND, JR ;
COLE, S ;
EFSTATHIOU, G ;
KAISER, N .
ASTROPHYSICAL JOURNAL, 1991, 379 (02) :440-460
[6]   The peak-patch picture of cosmic catalogs .2. Validation [J].
Bond, JR ;
Myers, ST .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1996, 103 (01) :41-62
[7]   CORE RADIUS AND DENSITY-MEASUREMENTS IN N-BODY EXPERIMENTS - CONNECTIONS WITH THEORETICAL AND OBSERVATIONAL DEFINITIONS [J].
CASERTANO, S ;
HUT, P .
ASTROPHYSICAL JOURNAL, 1985, 298 (01) :80-94
[8]   THE EVOLUTION OF LARGE-SCALE STRUCTURE IN A UNIVERSE DOMINATED BY COLD DARK MATTER [J].
DAVIS, M ;
EFSTATHIOU, G ;
FRENK, CS ;
WHITE, SDM .
ASTROPHYSICAL JOURNAL, 1985, 292 (02) :371-394
[9]   COLD DARK-MATTER .1. THE FORMATION OF DARK HALOS [J].
GELB, JM ;
BERTSCHINGER, E .
ASTROPHYSICAL JOURNAL, 1994, 436 (02) :467-490
[10]   MERGER RATES IN HIERARCHICAL-MODELS OF GALAXY FORMATION .2. COMPARISON WITH N-BODY SIMULATIONS [J].
LACEY, C ;
COLE, S .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1994, 271 (03) :676-692