The Star Formation Rate Intensity Distribution Function: Implications for the Cosmic Star Formation Rate History of the Universe
The Star Formation Rate Intensity Distribution Function: Implications for the Cosmic Star Formation Rate History of the Universe
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恒星形成率强度分布函数：对宇宙恒星形成率历史的影响
DOI：
10.1086/339774
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
A. Fernández
中科院分区：
文献类型：
--
作者：
K. Lanzetta;Noriaki Yahata;S. Pascarelle;Hsiao;A. Fernández
我们通过检查“无遮挡”恒星形成速率强度与红移的分布来解决宇宙表面亮度变暗对微弱星系观测的影响。我们使用恒星形成率强度分布函数来评估紫外线光度密度与红移的关系，基于我们对哈勃深场 (HDF) 和哈勃深场南 (HDF-S) 宽视场行星相机 2 以及近红外相机和多目标光谱仪场中微弱星系的光度测量和光度红移测量。我们发现（1）之前的测量通过忽略宇宙表面亮度变暗效应而错过了高红移时宇宙紫外线光度密度的主要部分，这在红移大于 z ≈ 2 时很重要； (2) 最高强度恒星形成区域的发生率随着红移单调增加； （3）通过观察到的最高红移，紫外光度密度似乎随着红移单调增加。通过测量光度密度与红移的光谱，我们还发现 (4) 之前在红移 z < 2 处测量的紫外光度密度必须减少约 2 倍，以允许静止帧波长 1500 和 2800 Å 之间的光度密度光谱。并且，通过与对背景准星体探测到的高红移阻尼Lyα吸收系统的观测进行比较，我们进一步发现，（5）恒星形成速率强度的分布与红移z ≈ 2-5处的中性氢柱密度分布相匹配，这在高红移星系和高柱密度气体之间建立了定量联系，并表明高红移阻尼Lyα吸收系统追踪在星光中检测到的相同星系的较低恒星形成速率强度区域在 HDF 和 HDF-S 中。因为我们的测量忽略了尘埃遮蔽的影响，所以它们代表了总恒星形成速率密度的下限。
We address the effects of cosmological surface brightness dimming on observations of faint galaxies by examining the distribution of "unobscured" star formation rate intensities versus redshift. We use the star formation rate intensity distribution function to assess the ultraviolet luminosity density versus redshift, based on our photometry and photometric redshift measurements of faint galaxies in the Hubble Deep Field (HDF) and the Hubble Deep Field-South (HDF-S) Wide Field Planetary Camera 2 and Near-Infrared Camera and Multi-Object Spectrometer fields. We find that (1) previous measurements have missed a dominant fraction of the ultraviolet luminosity density of the universe at high redshifts by neglecting cosmological surface brightness dimming effects, which are important at redshifts larger than z ≈ 2; (2) the incidence of the highest intensity star-forming regions increases monotonically with redshift; and (3) the ultraviolet luminosity density plausibly increases monotonically with redshift through the highest redshifts observed. By measuring the spectrum of the luminosity density versus redshift, we also find that (4) previous measurements of the ultraviolet luminosity density at redshifts z < 2 must be reduced by a factor of ≈2 to allow for the spectrum of the luminosity density between rest-frame wavelengths 1500 and 2800 Å. And, by comparing with observations of high-redshift damped Lyα absorption systems detected toward background quasi-stellar objects, we further find that (5) the distribution of star formation rate intensities matches the distribution of neutral hydrogen column densities at redshifts z ≈ 2-5, which establishes a quantitative connection between high-redshift galaxies and high column density gas and suggests that high-redshift damped Lyα absorption systems trace lower star formation rate intensity regions of the same galaxies detected in starlight in the HDF and HDF-S. Because our measurements neglect the effects of obscuration by dust, they represent lower limits to the total star formation rate density.