ON DETERMINING THE SHAPE OF MATTER DISTRIBUTIONS

被引：120

作者：

Zemp, Marcel ^{[1
]}

Gnedin, Oleg Y. ^{[1
]}

Gnedin, Nickolay Y. ^{[2
,3
,4
]}

Kravtsov, Andrey V. ^{[3
,4
]}

机构：

[1] Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA

[2] Fermilab Natl Accelerator Lab, Ctr Particle Astrophys, Batavia, IL 60510 USA

[3] Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA

[4] Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA

来源：

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES | 2011年 / 197卷 / 02期

基金：

美国国家科学基金会;

关键词：

methods: data analysis; methods: numerical; COLD DARK-MATTER; N-BODY SIMULATIONS; DISSIPATIONLESS COLLAPSE; HALOS; ALIGNMENT; UNIVERSE; MODELS; GAS; SUBSTRUCTURES; DEPENDENCE;

D O I：

10.1088/0067-0049/197/2/30

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

A basic property of objects, such as galaxies and halos that form in cosmological structure formation simulations, is their shape. Here, we critically investigate shape determination methods that are commonly used in the literature. It is found that using an enclosed integration volume and weight factors r(-2) and r(ell)(-2) (elliptical radius) for the contribution of each particle or volume element in the shape tensor leads to biased axis ratios and smoothing of details when calculating the local shape as a function of distance from the center. To determine the local shape of matter distributions as a function of distance for well-resolved objects (typically more than O(10(4)) particles), we advocate a method that (1) uses an ellipsoidal shell (homoeoid) as an integration volume without any weight factors in the shape tensor and (2) removes subhalos.

引用

页数：8

共 40 条

[1] The shape of dark matter haloes: dependence on mass, redshift, radius and formation [J].