Scale invariance of rich cluster abundance: A possible test for models of structure formation

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/27905

Title:	Scale invariance of rich cluster abundance: A possible test for models of structure formation
Authors:	Xu,W;Fang,LZ;Wu,XP
Contributors:	天文研究所
Keywords:	COLD DARK-MATTER;GALAXY CLUSTERS;UNIVERSE;RAY
Date:	1998
Issue Date:	2010-06-29 19:35:53 (UTC+8)
Publisher:	中央大學
Abstract:	We investigate the dependence of cluster abundance n(>M, r(cl)), i.e., the number density of clusters with mass larger than M within radius r(cl), on scale parameter r(cl). Using numerical simulations of clusters in the cold dark matter (CDM) cosmogonic theories, we notice that the abundance of rich clusters shows a simple scale invariance such that n[>(r(cl/)r(0))M-alpha,r(cl)] = n(>M, r(0)), in which the scaling index alpha remains constant in a scale range where halo clustering is fully developed. The abundances of scale r(cl) clusters identified from IRAS are found basically to follow this scaling and yield alpha similar to 0.5 in the range 1.5 < r(cl) < 4 h(-1) Mpc. The scaling gains further support from independent measurements of the index alpha using samples of X-ray and gravitational lensing mass estimates. We find that all the results agree within error limits as alpha similar to 0.5-0.7 in the range of 1.5 < r(cl) < 4 h(-1) Mpc. These numbers are in good consistency with the predictions of open CDM (OCDM) (Omega(M) = 0.3) and low-density, flat CDM model with a nonzero lambda (LCDM) (Omega(M) + Omega(A) = 1), whereas the standard CDM model has different behavior. The current result seems to favor models with a low mass density.
Relation:	ASTROPHYSICAL JOURNAL
Appears in Collections:	[Graduate Institute of Astronomy] journal & Dissertation

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	448	View/Open

社群 sharing

Loading...