We measure the environmental dependence, where environment is defined by the distance to the third nearest neighbor, of multiple galaxy properties inside the Environmental COntext (ECO) catalog. We focus primarily on void galaxies, which we define as the $10 \%$ of galaxies having the lowest local density. We compare the properties of void and non-void galaxies: baryonic mass, color, fractional stellar mass growth rate (FSMGR), morphology, and gas-to-stellar-mass ratio (estimated from a combination of HI data and photometric gas fractions calibrated with the RESOLVE survey). Our void galaxies typically have lower baryonic masses than galaxies in denser environments, and they display the properties expected of a lower mass population: they have more late-types, are bluer, have higher FSMGR, and are more gas rich. We control for baryonic mass and investigate the extent to which void galaxies are different at fixed mass. Void galaxies are bluer, more gas-rich, and more star forming at fixed mass than non-void galaxies, which is a possible signature of galaxy assembly bias. Furthermore, we show that these trends persist even at fixed mass and morphology, and we find that voids host a distinct population of early-types that are bluer and more star-forming than the typical red and quenched early-types. In addition to these empirical observational results, we also present theoretical results from mock catalogs with built-in galaxy assembly bias. We show that a simple matching of galaxy properties to (sub)halo properties, such as mass and age, can recover the observed environmental trends in ECO galaxies.

中文翻译：

---

虚空星系在环境上下文目录中遵循不同的进化路径

我们测量环境依赖性，其中环境由环境上下文 (ECO) 目录中的多个星系属性到第三个最近邻居的距离定义。我们主要关注空星系，我们将其定义为具有最低局部密度的星系的 $10\%$。我们比较了空心和非空心星系的特性：重子质量、颜色、恒星质量分数增长率 (FSMGR)、形态和气体质量比（根据 HI 数据和校准的光度气体分数估计与 RESOLVE 调查）。我们的虚空星系通常比密度较大的环境中的星系具有更低的重子质量，并且它们显示出质量较低的星系所预期的特性：它们具有更多的晚型、更蓝、更高的 FSMGR 和更富含气体。我们控制重子质量并研究空星系在固定质量下的不同程度。空心星系比非空心星系更蓝、更富含气体、以固定质量形成的恒星更多，这可能是星系组装偏差的一个标志。此外，我们表明即使在固定的质量和形态下，这些趋势仍然存在，并且我们发现空洞中存在着一群独特的早期类型，它们比典型的红色和淬灭的早期类型更蓝、更能形成恒星。除了这些经验观察结果之外，我们还展示了具有内置星系组装偏差的模拟目录的理论结果。我们表明，星系属性与（亚）晕属性（例如质量和年龄）的简单匹配可以恢复在 ECO 星系中观察到的环境趋势。