论文标题
量化星系中星系的RAM压力剥离的作用
Quantifying the role of ram pressure stripping of galaxies within galaxy groups
论文作者
论文摘要
人们经常指出，通过RAM压力剥离星系磁盘去除气体并不是星系组的常见过程。在这项研究中，借助星系的观察性分类和一个简单的物理模型，我们表明这可能不是事实。我们检查并鉴定了45个在125个光谱镜选择的星系组中的1311个星系组成员样本中的45个RAM压剥离的星系候选物。这些星系中有13个是具有多个不同特征的最安全的候选人。这些候选RAM压力剥离的星系具有与集群中的候选性能相似的特性 - 它们发生在一系列恒星质量，主要是蓝色和恒星形成，并且具有与首先是进入其组中的第一个输入器一致的相位空间分布。这些候选人的唯一突出特征是它们不存在于群集中，而是组为组，中位光晕质量为10 $^{13.5} $ M $ _ \ odot $。尽管这似乎令人惊讶，但我们采用了组中预期的RAM压力剥离力的分析模型，发现对相关的内部速度和内部培养基含量的合理估计将导致这些光晕质量的RAM压力剥离的星系。最后，鉴于RAM压力阶段的寿命存在很大的不确定性，如果可以确认我们的RAM压力剥离的候选者，则该物理机制可能是银河系中的主要淬火机制。
It is often stated that the removal of gas by ram pressure stripping of a galaxy disk is not a common process in galaxy groups. In this study, with the aid of an observational classification of galaxies and a simple physical model, we show that this may not be true. We examined and identified 45 ram-pressure stripped galaxy candidates from a sample of 1311 galaxy group members within 125 spectroscopically-selected galaxy groups. 13 of these galaxies are the most secure candidates with multiple distinct features. These candidate ram pressure stripped galaxies have similar properties to those found in clusters -- they occur at a range of stellar masses, are largely blue and star-forming and have phase-space distributions consistent with being first infallers into their groups. The only stand-out feature of these candidates is they exist not in clusters, but in groups, with a median halo mass of 10$^{13.5}$ M$_\odot$. Although this may seem surprising, we employ an analytic model of the expected ram pressure stripping force in groups and find that reasonable estimates of the relevant infall speeds and intragroup medium content would result in ram pressure stripped galaxies at these halo masses. Finally, given the considerable uncertainty on the lifetime of the ram-pressure phase, this physical mechanism could be the dominant quenching mechanism in galaxy groups, if our ram pressure stripped candidates can be confirmed.
