A Keck/DEIMOS Spectroscopy of Lyα Blobs at Redshift z = 3.1
A Keck/DEIMOS Spectroscopy of Lyα Blobs at Redshift z = 3.1
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DOI：
10.1086/503362
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发表时间：
2006-02
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影响因子：
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通讯作者：
Y. Matsuda;Toru Yamada;T. Hayashino;R. Yamauchi;Y. Nakamura
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文献类型：
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作者：
Y. Matsuda;Toru Yamada;T. Hayashino;R. Yamauchi;Y. Nakamura
本文利用10 m Keck望远镜上的DEIMOS光谱仪对37个候选Lyα斑点和红移z = 3.1的发射体样本进行了中分辨率（~2 Å）光谱分析。所有37个物体的发射线都被检测到，并且在它们的线轮廓中显示出变化。28个高质量天体的Lyα速度宽度（FWHM）在150 ~ 1700 km s-1范围内，与Lyα空间范围相关。所有12个Lyα团（≥16 arcsec2）的速度宽度都大于500 km s-1。虽然对Lyα的速度宽度有几种可能的物理解释（引力束缚的气体云的运动，流入，团块的合并，或来自超风的流出），Lyα团的大速度宽度表明它们是大质量星系形成的地方。如果我们假设重力束缚的气体云，Lyα团的动力质量估计为~1012-1013 M☉。即使在流出的情况下，流出的速度也很可能与从当地星暴星系的观测证据推断出的旋转速度相当。
We present the results of intermediate-resolution (~2 Å) spectroscopy of a sample of 37 candidate Lyα blobs and emitters at redshift z = 3.1 using the DEIMOS spectrograph on the 10 m Keck telescope. The emission lines are detected for all 37 objects and show variety in their line profiles. The Lyα velocity widths (FWHM) of the 28 objects with higher quality spectra, measured by fitting a single Gaussian profile, are in the range of 150-1700 km s-1 and correlate with the Lyα spatial extents. All 12 Lyα blobs (≥16 arcsec2) have large velocity widths of ≳500 km s-1. While there are several possible physical interpretations of the Lyα velocity widths (the motion of gravitationally bound gas clouds, inflows, the merging of clumps, or outflows from superwinds), the large velocity widths of the Lyα blobs suggest that they are the sites of massive galaxy formation. If we assume gravitationally bound gas clouds, the dynamical masses of the Lyα blobs are estimated to be ~1012-1013 M☉. Even for the case of outflows, the outflow velocities are likely to be comparable to the rotation velocities as inferred from the observational evidence for local starburst galaxies.