On spatial distributions of old globular clusters in clusters of galaxies

被引:28
作者
Bekki, Kenji [1 ]
Yahagi, Hideki
机构
[1] Univ New S Wales, Sch Phys, Sydney, NSW 2052, Australia
[2] Univ Tokyo, Dept Astron, Tokyo 1130033, Japan
关键词
globular clusters : general; galaxies : elliptical and lenticular; cD; galaxies : evolution; galaxies : interactions; galaxies : star clusters;
D O I
10.1111/j.1365-2966.2006.10833.x
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We investigate structural properties of old, metal-poor globular clusters (GCs) formed at high redshifts (z > 6) and located inside and outside virialized galaxy-scale haloes in clusters of galaxies with the total masses of M-CL based on high-resolution cosmological simulations with models of GC formation. We mainly derive the parameter dependences of physical properties of intracluster GCs (ICGCs) based on the results of 14 cluster models. Our principle results are summarized as follows. (1) ICGCs are formed as a result of tidal stripping of GCs initially within galaxy-scale haloes during hierarchical growth of clusters via halo merging. These ICGCs comprise 20-40 per cent of all GCs in clusters with 1.0 x 10(14) M-circle dot <= M-CL <= 6.5 x 10(14) M-circle dot and the number fraction of ICGCs does not depend on M-CL for the above cluster mass range. (2) The projected radial density profiles (Sigma(GC)) of ICGCs in clusters with different M-CL can be diverse, though ICGCs have inhomogeneous, asymmetric and somewhat elongated distributions in most models. If Sigma(GC)(R) proportional to R-alpha, alpha ranges from approximate to -1.5 to approximate to -2.5 for GCs in clusters with the above mass range. (3) Although total number of GCs within the central 0.05 Mpc (N-GC,N-0.05) and 0.2 Mpc (N-GC,N-0.2) are diverse in different clusters, they can depend weakly on M-CL in such a way that both N-GC,N-0.05 and N-GC,N-0.2 are likely to be larger for clusters with larger M-CL. (4) Total number of GCs per cluster masses (specific frequency of GCs for clusters of galaxies) are more likely to be larger in more massive clusters, mainly because a larger number of earlier virialized objects can be located in more massive clusters. (5) Radial density distributions of all GCs including ICGCs and galactic GCs have steeper profiles than those of the background dark matter haloes in the central regions of clusters (R < 200 kpc) with different M-CL. (6) Spatial distributions of old GCs in clusters can depend on the truncation epoch of GC formation (z(trun)) such that they can be steeper and more compact in the models with higher z(trun). (7) The mean metallicity of ICGCs in a cluster can be smaller than that of GCs within the cluster member galaxy-scale haloes by similar to 0.3 in [Fe/H]. Metallicity distribution functions (MDFs) of ICGCs show peak values around [Fe/H] similar to -1.6 and do not have remarkable bimodality.
引用
收藏
页码:1019 / 1033
页数:15
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