THE LYMAN ALPHA REFERENCE SAMPLE: EXTENDED LYMAN ALPHA HALOS PRODUCED AT LOW DUST CONTENT
THE LYMAN ALPHA REFERENCE SAMPLE: EXTENDED LYMAN ALPHA HALOS PRODUCED AT LOW DUST CONTENT
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DOI：
10.1088/2041-8205/765/2/l27
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发表时间：
2013-02
期刊：
影响因子：
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通讯作者：
Matthew Hayes;G. Östlin;D. Schaerer;A. Verhamme;J. Mas-Hesse;A. Adamo;H. Atek;J. Cannon;
中科院分区：
文献类型：
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作者：
Matthew Hayes;G. Östlin;D. Schaerer;A. Verhamme;J. Mas-Hesse;A. Adamo;H. Atek;J. Cannon;
我们报告了利用哈勃太空望远镜对莱曼 α 发射线 (Lyα) 进行的新成像观测，该发射线构成了莱曼 α 参考样本的主干。我们展示了在连续谱扣除的 Lyα、Hα 和远紫外连续谱中红移 0.028 < z < 0.18 的 14 个星暴星系的图像。我们表明，Lyα 的发射规模系统地超过了大质量恒星群和重组星云的规模：根据 Petrosian 20% 半径测量，RP20、Lyα 半径比 Hα 的半径大 1 到 3.6 倍，平均值为 2.4。 Lyα 与 FUV 半径的平均比率为 2.9。这表明大部分 Lyα 光通过共振散射被推向较大的半径。定义 Lyα 相对于 Hα 的相对 Petrosian 外延， ΨLyα = RLyαP20/RHαP20，我们发现 ΨLyα 与 Lyα 总光度不相关。然而，ψLyα 与随尘埃含量成比例的量密切相关，从某种意义上说，为了将 Lyα 光子传播到整个星际介质并驱动大延伸的 Lyα 晕，低尘埃丰度是必要条件（尽管不是唯一的要求）。
We report on new imaging observations of the Lyman alpha emission line (Lyα), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample. We present images of 14 starburst galaxies at redshifts 0.028 < z < 0.18 in continuum-subtracted Lyα, Hα, and the far ultraviolet continuum. We show that Lyα is emitted on scales that systematically exceed those of the massive stellar population and recombination nebulae: as measured by the Petrosian 20% radius, RP20, Lyα radii are larger than those of Hα by factors ranging from 1 to 3.6, with an average of 2.4. The average ratio of Lyα-to-FUV radii is 2.9. This suggests that much of the Lyα light is pushed to large radii by resonance scattering. Defining the Relative Petrosian Extension of Lyα compared to Hα, ξLyα = RLyαP20/RHαP20, we find ξLyα to be uncorrelated with total Lyα luminosity. However, ξLyα is strongly correlated with quantities that scale with dust content, in the sense that a low dust abundance is a necessary requirement (although not the only one) in order to spread Lyα photons throughout the interstellar medium and drive a large extended Lyα halo.