Redshifts of CLASS Radio Sources
Redshifts of CLASS Radio Sources
复制标题
CLASS 射电源的红移
DOI：
--
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
L. Koopmans
中科院分区：
文献类型：
--
作者：
D. R. Marlow;D. R. Marlow;D. Rusin;N. Jackson;P. Wilkinson;I. Browne;L. Koopmans
对宇宙透镜全天巡天（CLASS）的42个平谱射电源样本的光谱观测，在64%的完整性水平下，得到了平均红移为1.27，均方根扩展为0.95。该样品由5 GHz通量密度为25-50 mJy的源组成，使其成为研究红移分布的最暗的平谱射电样品。这些光谱由威廉·赫歇尔望远镜获得，主要由z > 1的宽线类星体和z < 0.5的窄线星系组成。虽然平谱射电源的平均红移在超过2个数量级的射电通量密度上几乎没有变化，但有证据表明，在较弱的通量水平上，类星体的比例会减少。我们提出了我们的光谱观测结果，并讨论了约束宇宙学参数的统计分析类的影响。
Spectroscopic observations of a sample of 42 flat-spectrum radio sources from the Cosmic Lens All-Sky Survey (CLASS) have yielded a mean redshift of ⟨z⟩ = 1.27 with an rms spread of 0.95, at a completeness level of 64%. The sample consists of sources with a 5 GHz flux density of 25–50 mJy, making it the faintest flat-spectrum radio sample for which the redshift distribution has been studied. The spectra, obtained with the William Herschel Telescope, consist mainly of broad-line quasars at z > 1 and narrow-line galaxies at z < 0.5. Though the mean redshift of flat-spectrum radio sources exhibits little variation over more than 2 orders of magnitude in radio flux density, there is evidence of a decreasing fraction of quasars at weaker flux levels. We present the results of our spectroscopic observations and discuss the implications for constraining cosmological parameters with statistical analyses of CLASS.