Clustering Segregation with Ultraviolet Luminosity in Lyman Break Galaxies at z~3 and Its Implications
Clustering Segregation with Ultraviolet Luminosity in Lyman Break Galaxies at z~3 and Its Implications
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莱曼裂痕星系 z~3 处紫外光度的团聚分离及其意义
DOI：
10.1086/319715
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
M. Dickinson
中科院分区：
文献类型：
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作者：
M. Giavalisco;M. Dickinson
报道了z ~ 3处莱曼破裂星系（LBG）的成团性质. LBG的通量限制样本的相关长度取决于它们在λ ~ 1700 nm处的静止帧紫外（UV）光度，较暗的星系在空间中的聚集程度较低。我们使用了三个通量极限逐渐变暗的样本：两个从我们的地面调查中提取，一个从哈勃深场（北部和南部）提取。在我们探测到的极限星等范围内，相关长度减少了1/3，即25 27，这表明具有较暗紫外光度极限的样本包括质量较小的星系。我们比较了冷暗物质（CDM）晕的成团强度的标度性质，发现：（1）在误差范围内，LBG的成团强度与体密度的标度关系与冷暗物质晕相同;以及（2）使用晕质量谱和一些模型预测星系的标度定律，将晕的质量映射到星系的紫外线光度只取决于质量和紫外线光度之间的紧密联系，但对模型的细节不敏感。我们解释这些结果作为额外的证据，强大的空间集群的LBG是由于星系偏置，支持偏置星系形成和引力不稳定性的理论作为主要的物理机制形成的结构。我们还拟合模型的质量-UV光度关系的数据，以再现同时从CDM晕质谱的相关长度与UV光度和光度函数的依赖性。我们已经发现（1）质量和UV光度之间的标度不变关系（例如，（2）对于大质量的LBG，一定质量的LBG的紫外光度散射一定较小，说明质量是控制这些系统中星星形成活动的一个重要参数;（3）在z ~ 3处的质量晕在紫外选择测量中没有观测到的比例并不大。从拟合中，对于给定的宇宙学选择，人们可以为LBG分配一个质量尺度。例如，如果Ω = 0.3和ΩΛ = 0.7，则光度分别为23、25.5和27.0的星系的平均质量分别为2.5、0.9和0.4 × 1012 M。在Ω = 0.2和ΩΛ = 0的开放宇宙和爱因斯坦-德西特宇宙学中，这些数字分别大2.2倍和小2.10倍。
We report on the clustering properties of Lyman break galaxies (LBGs) at z ~ 3. The correlation length of flux-limited samples of LBGs depends on their rest-frame ultraviolet (UV) luminosity at λ ~ 1700 Å, with fainter galaxies being less strongly clustered in space. We have used three samples with progressively fainter flux limits: two extracted from our ground-based survey and one from the Hubble Deep Fields (both North and South). The correlation length decreases by a factor of ≈3 over the range of limiting magnitudes that we have probed, namely, 25 ≲ ℛ ≲ 27, suggesting that samples with a fainter UV luminosity limit include galaxies with smaller mass. We have compared the observed scaling properties of the clustering strength with those predicted for cold dark matter (CDM) halos and found that (1) the clustering strength of LBGs follows, within the errors, the same scaling law with the volume density as the halos; and (2) the scaling law predicted for the galaxies using the halo mass spectrum and a number of models for the relationship that maps the halos' mass into the galaxies' UV luminosity depends only on how tightly mass and UV luminosity correlate but is otherwise insensitive to the details of the models. We interpret these results as additional evidence that the strong spatial clustering of LBGs is due to galaxy biasing, supporting the theory of biased galaxy formation and gravitational instability as the primary physical mechanism for the formation of structure. We have also fitted models of the mass-UV luminosity relationship to the data to reproduce simultaneously from the CDM halo mass spectrum the dependence of the correlation length with the UV luminosity and the luminosity function. We have found that (1) a scale invariant relationship between mass and UV luminosity (e.g., a power law) is not supported by the observations, suggesting that the properties of star formation of galaxies change along the mass spectrum of the observed LBGs; (2) the scatter of the UV luminosity of LBGs of given mass must be relatively small for massive LBGs, suggesting that the mass is an important parameter in regulating the activity of star formation in these systems; and (3) the fraction of massive halos at z ~ 3 that are not observed in UV-selected surveys is not large. From the fits, for a given choice of the cosmology, one can assign a scale of mass to the LBGs. For example, if Ω = 0.3 and ΩΛ = 0.7, the average mass of galaxies with luminosity ℛ = 23, 25.5, and 27.0 is = 2.5, 0.9, and 0.4 × 1012 M☉, respectively. The numbers are ≈2 times larger and ≈10 times smaller in an open universe with Ω = 0.2 and ΩΛ = 0 and in the Einstein-de Sitter cosmologies, respectively.