论文标题
银河系和大众组装(GAMA):在研究银河系中的明智的力量至$ z <0.1 $
Galaxy and Mass Assembly (GAMA): Demonstrating the power of WISE in the study of Galaxy Groups to $z<0.1$
论文作者
论文摘要
结合了来自银河系和大规模组装(GAMA)调查的高保真群体表征以及明智调查中的$ z <0.1 $光度法,我们进行了一项全面的研究,对未分组星系的特性进行了全面研究,而497个星系集团(4 $ \\ leq $ n $ _ $ _ {\ rm $ halo $ halo $ halo和20)未分组的星系在很大程度上是明智的颜色,这是由恒星形成的晚期星系所支配的。然而,分组的星系在明智的颜色上显示出明显的双峰性,这与恒星质量和形态密切相关。我们找到了越来越多的早期型分数的证据,在$ 10^{10} \ Lessim $ m $ _ {\ rm stellar} \ lyssim10^{11} $ m $ _ \ odot $之间,随着晕halo质量的增加。我们使用带有星形颜色的未组合的晚期星系(W2 $ - $ W3 $> 3 $ 3),我们定义了一个形成星形的主序列(SFMS),我们用来描述已移动到序列以下的系统(出于这项工作的目的“ Quenched”)。我们发现,随着光环质量的增加,SFMS上的晚期系统的相对数量减少,并且在高恒星质量的早期类型,淬灭系统的相应增加(M $ _ {\ rm Stellar}> {10}> {10}^{10.5}^{10.5}^{10.5} $ M $ _ $ _ \ odot $),一致的quench。带有群体的组星系,m $ _ {\ rm stellar} <{10}^{10.5} $ m $ _ \ odot $显示了与环境驱动过程一致的淬火证据。晚期,淬火星系的恒星质量分布表明,随着系统从恒星形成和晚期型到“红色序列”的过渡,它们可能是中间人口。最后,我们使用天空上的群体的预计区域来提取(相对)对其光晕质量的组。尽管与名义组相比,它们的高质量和早期星系的比例略有增加,但淬灭分数明显增加并不明显。
Combining high-fidelity group characterisation from the Galaxy and Mass Assembly (GAMA) survey and source-tailored $z<0.1$ photometry from the WISE survey, we present a comprehensive study of the properties of ungrouped galaxies, compared to 497 galaxy groups (4$\leq$ N$_{\rm FoF}$ $\leq$ 20) as a function of stellar and halo mass. Ungrouped galaxies are largely unimodal in WISE color, the result of being dominated by star-forming, late-type galaxies. Grouped galaxies, however, show a clear bimodality in WISE color, which correlates strongly with stellar mass and morphology. We find evidence for an increasing early-type fraction, in stellar mass bins between $10^{10}\lesssim$M$_{\rm stellar} \lesssim10^{11}$ M$_\odot$, with increasing halo mass. Using ungrouped, late-type galaxies with star-forming colors (W2$-$W3$>$3), we define a star-forming main-sequence (SFMS), which we use to delineate systems that have moved below the sequence ("quenched" for the purposes of this work). We find that with increasing halo mass, the relative number of late-type systems on the SFMS decreases, with a corresponding increase in early-type, quenched systems at high stellar mass (M$_{\rm stellar}>{10}^{10.5}$ M$_\odot$), consistent with mass quenching. Group galaxies with masses M$_{\rm stellar}<{10}^{10.5}$ M$_\odot$ show evidence of quenching consistent with environmentally-driven processes. The stellar mass distribution of late-type, quenched galaxies suggests they may be an intermediate population as systems transition from being star-forming and late-type to the "red sequence". Finally, we use the projected area of groups on the sky to extract groups that are (relatively) compact for their halo mass. Although these show a marginal increase in their proportion of high mass and early-type galaxies compared to nominal groups, a clear increase in quenched fraction is not evident.