We study the dependence of Lyα escape from galaxies on UV continuum size and luminosity using a sample of 40 Green Pea (GP) galaxies, which are the best local analogs of high-redshift Lyα emitters (LAEs). We use the Cosmic Origins Spectrograph near-ultraviolet images from the Hubble Space Telescope to measure the UV size and luminosity with 0.″047 spatial resolution. Like most galaxies the GPs show a log-normal size distribution. They also show a positive correlation between size and UV-continuum luminosity. The slope of the size-continuum luminosity relation for GPs is consistent with those of continuum-selected star-forming galaxies (SFGs) at low and high redshifts. A distinctive feature of GPs is a very compact typical radius of 0.33 kpc with a population spread (1σ) of 0.19 kpc. The peak of the size distribution and the intercept of the size–luminosity relation of GPs are noticeably smaller than those of continuum-selected SFGs at similar redshifts. There are statistically significant anticorrelations found between the circularized half-light radius (r _cir,50), the Lyα equivalent width (EW(Lyα)), and the Lyα escape faction (), suggesting that small UV-continuum radii are crucial for Lyα emission. GPs and high-redshift LAEs have similar sizes, once spatial resolution effects are properly considered. Our results show that a compact small size is crucial for escape of Lyα photons, and that Lyα emitters show constant characteristic size independent of their redshift.

我们使用 40 个绿豌豆 (GP) 星系的样本研究了 Ly α从星系逃逸对紫外线连续谱大小和光度的依赖性，这些星系是高红移 Ly α发射体 (LAE)的最佳局部类似物。我们使用来自哈勃太空望远镜的宇宙起源光谱仪近紫外图像以 0.″047 空间分辨率测量紫外线大小和光度。像大多数星系一样，GP 显示出对数正态大小分布。它们还显示出尺寸和紫外线连续谱光度之间的正相关关系。GPs 大小-连续谱光度关系的斜率与连续谱选择的恒星形成星系 (SFG) 在低红移和高红移下的斜率一致。GPs 的一个显着特征是非常紧凑的典型半径为 0.33 kpc，人口分布（1 σ) 的 0.19 kpc。在相似的红移下，GPs 的尺寸分布峰值和尺寸-光度关系的截距明显小于连续谱选择的 SFG。在圆形半光半径 ( r _cir,50 )、Ly α等效宽度 (EW(Ly α )) 和 Ly α逃逸派系 ( )之间发现统计上显着的反相关性，表明小的 UV 连续谱半径是对 Ly α发射至关重要。一旦适当考虑了空间分辨率效应，GP 和高红移 LAE 具有相似的尺寸。我们的结果表明，紧凑的小尺寸对于 Ly α光子的逃逸至关重要，并且 Ly α 发射器显示出与其红移无关的恒定特征尺寸。