论文标题
紧凑型星系中ETG的恒星种群特性
Stellar Population Properties of ETGs in Compact Groups of Galaxies
论文作者
论文摘要
我们介绍了属于151个紧凑型组（CGS）的早期星系（ETG）的恒星种群研究的结果。我们还选择了由846个ETG组成的现场样品来研究对星系进化的环境影响。我们发现，无论ETG居住在何处，平均恒星年龄，[z/h]和[$α$/fe]对中央恒星速度分散的依赖性相似。与文献中的中心和卫星样本相比，我们发现GC中的ETG与中心相似，尤其是嵌入低质量光环中的中心（$ M_ {H} <10^ {12.5} {12.5} M _ {\ odot} $）。除了低质量极限（在CGS中未见的恒星标志）外，CG和田间星系中气体的电离剂似乎相似，并且由于发热的低质量恒星。但是，相对于CGS中的ETG，场ETG呈现出过量的H $α$发射。此外，我们进行了动态分析，该分析表明CGS在组速度分散分布中具有双峰性 - 高和低$σ$模式。我们的结果表明，与低$σ$组相比，高$σ$组具有较小的螺旋，较短的穿越时间和更发光的星系人群。重要的是要强调，我们的发现表明对位于CGS中的星系的环境影响很小。我们发现的唯一证据是气体含量的变化，表明环境驱动的气体损失。
We present results on the study of the stellar population in Early-Type galaxies (ETGs) belonging to 151 Compact Groups (CGs). We also selected a field sample composed of 846 ETGs to investigate environmental effects on galaxy evolution. We find that the dependences of mean stellar ages, [Z/H] and [$α$/Fe] on central stellar velocity dispersion are similar, regardless where the ETG resides, CGs or field. When compared to the sample of centrals and satellites from the literature, we find that ETGs in GCs behave similarly to centrals, especially those embedded in low-mass haloes ($M_{h} < 10^ {12.5}M_{\odot}$). Except for the low-mass limit, where field galaxies present a Starforming signature, not seen in CGs, the ionization agent of the gas in CG and field galaxies seem to be similar and due to hot, evolved low-mass stars. However, field ETGs present an excess of H$α$ emission relative to ETGs in CGs. Additionally, we performed a dynamical analysis, which shows that CGs present a bimodality in the group velocity dispersion distribution - a high and low-$σ$ mode. Our results indicate that high-$σ$ groups have a smaller fraction of spirals, shorter crossing times, and a more luminous population of galaxies than the low $σ$ groups. It is important to emphasize that our findings point to a small environmental impact on galaxies located in CGs. The only evidence we find is the change in gas content, suggesting environmentally-driven gas loss.
