THE LYMAN ALPHA REFERENCE SAMPLE. II. HUBBLE SPACE TELESCOPE IMAGING RESULTS, INTEGRATED PROPERTIES, AND TRENDS
THE LYMAN ALPHA REFERENCE SAMPLE. II. HUBBLE SPACE TELESCOPE IMAGING RESULTS, INTEGRATED PROPERTIES, AND TRENDS
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DOI：
10.1088/0004-637x/782/1/6
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发表时间：
2013-08
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影响因子：
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通讯作者：
M. Hayes;M. Hayes;M. Hayes;G. Östlin;F. Duval;A. Sandberg;L. Guaita;J. Melinder;A. Adamo
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文献类型：
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作者：
M. Hayes;M. Hayes;M. Hayes;G. Östlin;F. Duval;A. Sandberg;L. Guaita;J. Melinder;A. Adamo
我们报告了关于星系Lyα输出的新结果，这些结果来自于莱曼α参考样本，并集中在哈勃空间望远镜成像上。给出了14个星系的Lyα、Hα和UV强度图像，以及Hα/Hβ、Lyα等效宽度（EW）和Lyα/Hα图。我们给出了Lyα和UV径向光分布，并表明它们与Sérsic分布很好地拟合，但Lyα分布的指数系统地低于UV的指数（n = 1-2而不是n = 4）。这揭示了普遍缺乏在紫外线中普遍存在的Lyα的中心浓度。Lyα的光度增长曲线比远紫外线增长更慢，表明小孔径可能低估了EW。然而，对于大多数星系来说，通量和EW曲线在半径为10 kpc时变平，这表明如果放置在高z位置，只有少数星系会遭受大的通量损失。我们计算了样品在大孔径下的整体性质，并表明总Lyα光度与所有其他量无关。然而，标准化的Lyα通量显示出显著的相关性：在星星形成率、尘埃含量、质量和星云数量较低的星系中，逃逸率较高，这表明电离连续性较强，金属丰度较低。根据它们的光度和EW，将选择6个星系作为高z Lyα发射体。我们讨论了高z Lyα和UV样品的结果。少数星系的EW超过50 °，其中一个显示80%;这样的物体以前没有在低z下报道过。
We report new results regarding the Lyα output of galaxies, derived from the Lyman Alpha Reference Sample, and focused on Hubble Space Telescope imaging. For 14 galaxies we present intensity images in Lyα, Hα, and UV, and maps of Hα/Hβ, Lyα equivalent width (EW), and Lyα/Hα. We present Lyα and UV radial light profiles and show they are well-fitted by Sérsic profiles, but Lyα profiles show indices systematically lower than those of the UV (n ≈ 1–2 instead of ≳ 4). This reveals a general lack of the central concentration in Lyα that is ubiquitous in the UV. Photometric growth curves increase more slowly for Lyα than the far ultraviolet, showing that small apertures may underestimate the EW. For most galaxies, however, flux and EW curves flatten by radii ≈10 kpc, suggesting that if placed at high-z only a few of our galaxies would suffer from large flux losses. We compute global properties of the sample in large apertures, and show total Lyα luminosities to be independent of all other quantities. Normalized Lyα throughput, however, shows significant correlations: escape is found to be higher in galaxies of lower star formation rate, dust content, mass, and nebular quantities that suggest harder ionizing continuum and lower metallicity. Six galaxies would be selected as high-z Lyα emitters, based upon their luminosity and EW. We discuss the results in the context of high-z Lyα and UV samples. A few galaxies have EWs above 50 Å, and one shows of 80%; such objects have not previously been reported at low-z.