Formation of intracluster and intercluster globular clusters

Abstract

Based on high-resolution cosmological simulations with models of GC formation at high redshifts (z > 6), we investigate structural and kinematical properties of intracluster globular clusters (ICGCs) that are located outside virialized galaxy-scale halos yet within clusters of galaxies with the total masses of MCL. We find that these ICGCs are formed as a result of tidal stripping of GCs initially within galaxy-scale halos during hierarchical growth of clusters via halo merging. We also find that ICGCs comprise 20-40% of all GCs in clusters with 1.0 × 1014 M⊙ ≤ MCL ≤ 6.5 × 1014 M⊙. Furthermore, the projected radial density profiles (∑GC) of all GCs in clusters with different MCL are found to be quite diverse. If ∑GC (R) α Rα, ranges from ≈ -1.5 to ≈ -2.5 for GCs in clusters with the above mass range. ∑GC is demonstrated to be dependent on the truncation epoch of GC formation at high redshifts by cosmological processes such as reionization. About ∼ 1% of all GCs formed before z>6 can not be within any galaxy-scale halos and thus identified as intercluster or intergroup (or intergalactic) GCs. © 2009 Springer-Verlag Berlin Heidelberg.