Creation and Destruction of Dwarf Galaxies in Interactions: Evaluating the Environmental Influences and the Global Importance

jane charlton这个提议的目的是对34个希克森致密星系群中的838个候选矮星系进行详细的调查。计划是获得光谱（获得金属丰度），多波段成像（调查恒星种群和年龄）和HI观测（识别潮汐尾）。这些观测结果将被用来试图区分矮星系，矮星系是在大星系被潮汐破坏后留下的碎片中形成的，而矮星系是原始形成的。潮汐矮星系长期以来一直被认为是星系相互作用碎片中的偶尔闯入者。提议者最近对希克森致密星系群中的矮星系进行了一次普查，结果强烈表明潮汐矮星系的形成是相当普遍的。根据种群的生存能力，这个过程可能相当重要，甚至与矮星的原始形成相比也是如此。该计划结合了8米霍比-埃伯利望远镜获得的光谱，哈勃太空望远镜的图像，以及形成矮星的中性氢的甚大阵列射电图。有了这些数据，我们将比较潮汐矮星系与群体中其他星系的特性，寻找将离开的矮星系与其母体连接起来的HI桥，并评估矮星系在紧密群体环境中的生存能力。如果这项研究的结果被外推到考虑其他环境，它将有可能评估潮汐矮星的形成是否仅仅是宇宙中偶尔的好奇心之一，或者它是否对我们对星系形成的整体理解很重要。本项目由美国国家科学基金会星系外天文学和宇宙学项目（AST/EXC）资助

AST-0071223Jane CharltonThe aim of this proposal is to conduct a detailed investigation of 838 dwarf galaxy candidates in 34 Hickson Compact groups. The plan is to obtain spectroscopy (to derive metalicities), multiband imaging (to investigate stellar populations and ages) and HI observations (to identify tidal tails). These observations will be used to try and distinguish between dwarf galaxies which have been formed in the debris left behind when larger galaxies were tidally disrupted and those which were formed primordially.Tidal dwarf galaxies have long been recognized as occasional interlopers in the debris of galaxy interactions. The proposers have recently conducted a census of the dwarf galaxy population in Hickson compact groups, and the results strongly suggest that tidal dwarf galaxy formation is quite common. Depending on the survivability of the population, this process may be quite significant, even as compared to primordial formation of dwarfs. The proposed project incorporates spectra obtained with the 8-m Hobby-Eberly Telescope, Hubble Space Telescope images, and Very Large array radio maps of the neutral Hydrogen from which the dwarfs form. With these data, we will compare properties of tidal dwarf galaxies to the galaxies at large in the groups, look for HI bridges connecting departing dwarfs to their parents, and assess the survivability of the dwarfs in the compact group environment. If the results of this study are extrapolated to consider other environments, it will be possible to evaluate if tidal dwarf formation is merely one of the occasional curiosities of the universe, or if it is important to our overall understanding of galaxy formation. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***