MEASUREMENT OF GALAXY CLUSTERING AT z ∼ 7.2 AND THE EVOLUTION OF GALAXY BIAS FROM 3.8 < z < 8 IN THE XDF, GOODS-S, AND GOODS-N
MEASUREMENT OF GALAXY CLUSTERING AT z ∼ 7.2 AND THE EVOLUTION OF GALAXY BIAS FROM 3.8 < z < 8 IN THE XDF, GOODS-S, AND GOODS-N
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XDF、GOODS-S 和 Goods-N 中 z 〜 7.2 处星系团的测量以及从 3.8 < z < 8 开始星系偏置的演化
DOI：
10.1088/0004-637x/793/1/17
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
P. V. Dokkum
中科院分区：
文献类型：
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作者：
R. Barone;M. Trenti;J. Wyithe;R. Bouwens;P. Oesch;P. Oesch;G. Illingworth;C. Carollo;Jian Su;M. Stiavelli;I. Labbé;P. V. Dokkum
哈勃太空望远镜的广域相机3在重新电离(z≳6)过程中观测到的莱曼破裂星系(LBG)样本的大小足以表征它们的星系团特性。使用来自哈勃极深场和CANDELS观测的组合星表，在z⩾6.5时包含N=743个LBG候选星，平均红移为，我们在≳4σ的角相关函数中探测到一个清晰的聚集信号，对应于实际空间相关长度Cmpc。得出的星系偏差是指z=7.2时的暗物质晕，并强调了低于当前探测极限(MAB∼−17.7)的星系预计将出现较低质量的晕(M∼108-1010.5)。在相同的调查中，我们计算了在z∼3.8−z∼5.9的LBG的ACF。从(b∼3.0)到(b∼8.6)发现了偏差增加的趋势，与固定光度的星系在4≲z≲6时被托管在类似质量的暗物质晕中大体一致，随后在z≳7时晕质量略有增加(∼2σ置信度)。在样本的中值光度(MUV=−19.4)下分离数据显示，明亮星系(Cmpc，)比暗星系(Cmpc，)的聚集度更高，这意味着质量与光比是恒定的。在不确定性较大的样本中也存在类似的趋势。最后，我们的偏差测量使我们能够调查托管UV明亮星系的暗物质晕的比例(占空比，ϵDC)。接近单位的AT值是首选的，这可能是由于在高红移时晕的组装时间缩短所致。
Lyman-break galaxy (LBG) samples observed during reionization (z ≳ 6) with the Hubble Space Telescope's Wide Field Camera 3 are reaching sizes sufficient to characterize their clustering properties. Using a combined catalog from the Hubble eXtreme Deep Field and CANDELS surveys, containing N = 743 LBG candidates at z ⩾ 6.5 at a mean redshift of , we detect a clear clustering signal in the angular correlation function (ACF) at ≳ 4σ, corresponding to a real-space correlation length cMpc. The derived galaxy bias is that of dark matter halos of at z = 7.2, and highlights that galaxies below the current detection limit (MAB ∼ −17.7) are expected in lower-mass halos (M ∼ 108–1010.5 ). We compute the ACF of LBGs at z ∼ 3.8 − z ∼ 5.9 in the same surveys. A trend of increasing bias is found from (b ∼ 3.0) to (b ∼ 8.6), broadly consistent with galaxies at fixed luminosity being hosted in dark matter halos of similar mass at 4 ≲ z ≲ 6, followed by a slight rise in halo masses at z ≳ 7 (∼2σ confidence). Separating the data at the median luminosity of the sample (MUV = −19.4) shows higher clustering at for bright galaxies (cMpc, ) compared to faint galaxies (cMpc, ) implying a constant mass-to-light ratio . A similar trend is present in the sample with larger uncertainty. Finally, our bias measurements allow us to investigate the fraction of dark matter halos hosting UV-bright galaxies (the duty cycle, ϵDC). At values near unity are preferred, which may be explained by the shortened halo assembly time at high redshift.