New Insight on Galaxy Formation and Evolution from Keck Spectroscopy of the Hawaii Deep Fields
New Insight on Galaxy Formation and Evolution from Keck Spectroscopy of the Hawaii Deep Fields
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DOI：
10.1086/118058
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发表时间：
1996-06
期刊：
影响因子：
--
通讯作者：
L. Cowie;A. Songaila;E. Hu;J. Cohen
中科院分区：
文献类型：
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作者：
L. Cowie;A. Songaila;E. Hu;J. Cohen
我们提出的光谱研究的结果与LRIS光谱仪凯克的两个夏威夷深调查领域。观测到的393个天体覆盖了26.2平方弧分的面积，构成了一个几乎完整的样本，K = 20，I = 23，B = 24.5。描述了K带静止坐标系光度函数及其随红移的演化。与文献中的其他光学选择（B和I）样品进行了比较，并给出了相应的静止坐标系B带光度函数的演化。在B = 24附近的B带计数显示出是一个混合的正常星系在适度的红移和星系经历快速星星形成，具有广泛的质量范围，并在红移间隔从z = 0.2到超过z = 1.7。在光学和红外波长的光度函数，数量计数，和颜色分布进行了讨论的星系样本的恒星形成历史的一致的图片。[OII]发射线诊断或静止帧紫外-红外颜色信息与静止帧绝对K星等结合使用，以构建一个"基本平面“，其中可以显示全球恒星形成率随红移的演变，我们还发现，在快速星星形成过程中，星系的最大静止坐标系K光度从L* 附近开始，随着红移的减小而平滑地下降在z > 1处。这种由星星形成主导的星系特征光度的平滑下降可以同时解释在微弱星等处的高B带星系计数和在B和K选择样本中z < 1处的红移分布。最后，讨论了K波段光密度演化作为恒星重子质量的示踪，并与星星形成速率进行了比较。
We present the results of spectroscopic studies with the LRIS spectrograph on Keck of two of the Hawaii deep survey fields. The 393 objects observed cover an area of 26.2 square arcmin and constitute a nearly complete sample down to K = 20, I = 23, and B = 24.5. The rest-frame K-band luminosity function and its evolution with redshift are described. Comparisons are made with other optically selected (B and I) samples in the literature, and the corresponding rest-frame B-band luminosity function evolution is presented. The B-band counts near B = 24 are shown to be a mixture of normal galaxies at modest redshifts and galaxies undergoing rapid star formation, which have a wide range of masses and which are spread over the redshift interval from z = 0.2 to beyond z = 1.7. The luminosity functions, number counts, and color distributions at optical and IR wavelengths are discussed in terms of a consistent picture of the star-forming history of the galaxy sample. [OII] emission-line diagnostics or rest-frame ultra-violet--infrared color information are used in combination with rest-frame absolute K magnitudes to construct a ``fundamental plane'' in which the evolution of the global star-formation rate with redshift can be shown, and we find that the maximum rest-frame K luminosity of galaxies undergoing rapid star formation has been declining smoothly with decreasing redshift from a value near L* at z > 1. This smooth decrease in the characteristic luminosity of galaxies dominated by star formation can simultaneously account for the high B-band galaxy counts at faint magnitudes and the redshift distribution at z < 1 in both the B- and K-selected samples. Finally, the overall K-band light density evolution is discussed as a tracer of the baryonic mass in stars and compared with the rate of star formation.