Luminosity-Dependent Clustering of Star-forming BzK Galaxies at Redshift 2
Luminosity-Dependent Clustering of Star-forming BzK Galaxies at Redshift 2
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DOI：
10.1086/513068
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发表时间：
2007-01
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通讯作者：
M. Hayashi;K. Shimasaku;K. Motohara;Makiko Yoshida;S. Okamura;N. Kashikawa
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作者：
M. Hayashi;K. Shimasaku;K. Motohara;Makiko Yoshida;S. Okamura;N. Kashikawa
我们使用Daddi et al.to提出的BzK颜色选择，从斯巴鲁深场的180弧分2中获得了1092个微弱的恒星形成星系（sBzK）的样本。这个样本代表了恒星形成星系的1.4 z <$2.5到KAB = 23.2，这大致相当于恒星质量的极限为101 × 1010 M。我们测量了这些sBzK的角相关函数（ACF）为w（θ）=（0.58 ± 0.13）× θ（arcsec）-0.8，并在合理的红移分布下将振幅转化为相关长度。由此得到的值r 0 = 3.2 h-1 Mpc，表明我们的sBzK存在于典型质量为2.8 × 1011 M的晕中。将这一晕质量估计与Kong等人对较亮样本的估计相结合，我们发现暗晕的质量随着K亮度（恒星质量的一种度量）的增加而增加; 2 K亮度增加1/10，暗晕的质量就增加102-103。我们还发现，晕占领数，在黑暗的晕托管的星系数量，是更高的明亮sBzK的。与其他星系群的比较表明，在z ~ 2处的暗sBzK（KAB < 23.2）和莱曼破裂星系是由相对较低质量的晕所承载的类似星系群，而明亮的sBzK（KAB < 21）则居住在与遥远的红色星系和极红天体相当或更大质量的晕中。使用扩展的Press-Schechter形式主义，我们预测，目前的后代的晕主办sBzK的跨度很宽的质量范围取决于K亮度，从低于银河系的那些最富有的集群。
We use the BzK color selection proposed by Daddi et al.to obtain a sample of 1092 faint star-forming galaxies (sBzK's) from 180 arcmin2 in the Subaru Deep Field. This sample represents star-forming galaxies at 1.4 ≲ z ≲ 2.5 down to KAB = 23.2, which roughly corresponds to a stellar-mass limit of ≃1 × 1010 M☉. We measure the angular correlation function (ACF) of these sBzK's to be w(θ) = (0.58 ± 0.13) × θ(arcsec)-0.8 and translate the amplitude into the correlation length assuming a reasonable redshift distribution. The resulting value, r0 = 3.2 h-1 Mpc, suggests that our sBzK's reside in halos with a typical mass of 2.8 × 1011 M☉. Combining this halo mass estimate with those for brighter samples of Kong et al., we find that the mass of dark halos largely increases with K brightness, a measure of the stellar mass; the dark halo mass increases by as much as 102-103 as K brightness increases by only a factor of ≃10. We also find that the halo occupation number, the number of galaxies hosted in a dark halo, is higher for brighter sBzK's. Comparison with other galaxy populations suggests that faint sBzK's (KAB < 23.2) and Lyman break galaxies at z ~ 2 are similar populations hosted by relatively low-mass halos, while bright sBzK's (KAB < 21) reside in halos comparable to or more massive than those of distant red galaxies and extremely red objects. Using the extended Press-Schechter formalism, we predict that present-day descendants of halos hosting sBzK's span a wide mass range depending on K brightness, from lower than that of the Milky Way up to those of richest clusters.