From Star Clusters to Dwarf Galaxies and Galactic Nuclei

强烈的星星形成爆发通常会产生大质量（超级）星星团（SSC）。在特别强烈的情况下，SSC被分组为团块，或恒星超星系团，在一个只有几百pc的区域内包含几十到几百个SSC。这种强烈的恒星形成事件可能是典型的早期星系组装时，富含气体的晚型原星系大量相互作用。超星系团的动力学演化首先由组成超星系团的SSCs的形成机制所主导，然后在几个超星系团的交叉时间内，SSCs相继合并。由此产生的物体成为卫星，可能（i）从宿主星系中驱逐出来，形成孤立的矮星系，（ii）围绕宿主星系运行，形成低质量卫星，（iii）继续在宿主星系盘内运行，或（iv）落向宿主星系的中心，形成核。上述（i）及（ii）的可能性令人振奋，因为（a）最近有人认为某些矮不规则星系可能与潮汐矮星系有关，而潮汐矮星系是在相互作用星系的潮汐尾中形成，并含有SSC的组合;及（B）最近在天炉座星系团中发现一类新星系，即超致密矮星系。最近在两个透镜状星系的盘中探测到一类新的星星团，即暗模糊星团（FFs），这种可能性很高（iii），这可能也与在银河系盘内运行的神秘的w Cen球状星团有关。许多晚型盘状星系的核心由相对年轻的星星团组成，这一认识使得可能性（iv）非常有趣。

Intense star formation bursts typically produce massive (super) star clusters (SSCs). In especially intense instances, the SSCs are grouped into clumps, or stellar superclusters, containing from a few-dozen to a few-hundred SSCs within a region spanning only a few hundred pc. Such intense star-formation events may have been typical during early galaxy assembly when gas-rich late-type proto-galaxies interactes profusely. The dynamical evolution of superclusters is dominated initially by the formation mechanism of the constituent SSCs, followed by the successive merging of the SSCs within a few supercluster crossing times. The resulting objects become satellites that may either (i) be expelled from the host galaxy forming isolated dwarf galaxies, (ii) orbit about the host forming low-mass satellites, (iii) continue to orbit within the disk of the host or (iv) fall towards the centre of the host forming a nucleus. The above possibilities (i) & (ii) are exciting in view of (a) recent suggestions that some dwarf irregular galaxies may be related to tidal dwarf galaxies which are observed to form in the tidal tails of interacting galaxies and contain assemblages of SSCs, and (b) the very recent finding of a new class of galaxy, namely the ultra-compact dwarf galaxies (UCDs), in the Fornax galaxy cluster. The very recent detection of a new class of star clusters, the faint fuzzies (FFs), in the disks of two lenticular galaxies is highly for possibility (iii), which is probably also relevant for the enigmatic w Cen globular cluster that orbits within the disk of the Milky Way. The realisation that many late-type disk galaxies have nuclei consisting of relatively young star clusters makes possibility (iv) highly interesting.