The 2dF-SDSS LRG and QSO survey: QSO clustering and the L-z degeneracy
The 2dF-SDSS LRG and QSO survey: QSO clustering and the L-z degeneracy
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DOI：
10.1111/j.1365-2966.2007.12552.x
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发表时间：
2006-12
影响因子：
4.8
通讯作者：
J. daÂngela;T. Shanks;S. Croom;P. Weilbacher;Robert J. Brunner;W. Couch;L. Miller;A. D. Myers-A.-D.-M
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文献类型：
--
作者：
J. daÂngela;T. Shanks;S. Croom;P. Weilbacher;Robert J. Brunner;W. Couch;L. Miller;A. D. Myers-A.-D.-M
我们将来自2dF- QSO红移巡天（2QZ）和2dF-斯隆数字巡天（LRG）和QSO巡天（2dF- sdss LRG和QSO，以下简称2SLAQ）的准恒星天体（QSO）样本结合起来，研究了z ~ 1.5个QSO的聚类并测量了相关函数（ξ）。在红移空间和沿天空方向投影的聚类信号与之前单独从2QZ样本获得的聚类信号相似。通过拟合沿视界和视界测量的相关函数ξ(σ, π)的函数形式，我们发现，如预期的那样，动力学落参量β和宇宙密度参量Ω0m是简并的。然而，这种简并可以通过在不同的宇宙学情景下使用线性理论预测来消除。结合2QZ和2SLAQ的QSO数据，我们得到：βQSO(z= 1.5) = 0.60+0.14−0.11，Ω0m= 0.25+0.09−0.07，这意味着QSO偏差值，b(z= 1.4) = 1.5±0.2。2QZ和较暗的2SLAQ QSO样品的结合进一步表明，在固定红移时，QSO聚类并不强烈依赖光度。这一结果与简单的“高峰”偏倚模型的预期不一致，在这种模型中，更多的发光，罕见的qso被假设居住在更高质量的光晕中。这些数据与预测不同光度的量子黑洞存在于质量相似的光晕中的模型更为一致。通过假设密度扰动坍缩的椭球模型，我们估计qso所在的暗物质晕的质量为~ 3 × 1012 h−1 M⊙。我们发现这个光晕质量不随红移而强烈演化，也不依赖于QSO的光度。假设光晕与黑洞质量的一系列关系，研究了黑洞质量与光度和红移的关系，并确定了Eddington效率与黑洞质量的关系。我们的结果表明，不同光度的量子黑洞可能包含质量相似的黑洞。
We combine the quasi-stellar object (QSO) samples from the 2dF QSO Redshift Survey (2QZ) and the 2dF-Sloan Digital Sky Survey luminous red galaxy (LRG) and QSO Survey (2dF-SDSS LRG and QSO, hereafter 2SLAQ) in order to investigate the clustering of z∼ 1.5 QSOs and measure the correlation function (ξ). The clustering signal in redshift-space and projected along the sky direction is similar to that previously obtained from the 2QZ sample alone. By fitting functional forms for ξ(σ, π), the correlation function measured along and across the line of sight, we find, as expected, that β, the dynamical infall parameter and Ω0m , the cosmological density parameter, are degenerate. However, this degeneracy can be lifted by using linear theory predictions under different cosmological scenarios. Using the combination of the 2QZ and 2SLAQ QSO data, we obtain: βQSO(z= 1.5) = 0.60+0.14−0.11, Ω0m= 0.25+0.09−0.07 which imply a value for the QSO bias, b(z= 1.4) = 1.5 ± 0.2 . The combination of the 2QZ with the fainter 2SLAQ QSO sample further reveals that QSO clustering does not depend strongly on luminosity at fixed redshift. This result is inconsistent with the expectation of simple 'high peaks' biasing models where more luminous, rare QSOs are assumed to inhabit higher mass haloes. The data are more consistent with models which predict that QSOs of different luminosities reside in haloes of similar mass. By assuming ellipsoidal models for the collapse of density perturbations, we estimate the mass of the dark matter haloes which the QSOs inhabit as ∼3 × 1012 h−1 M⊙ . We find that this halo mass does not evolve strongly with redshift nor depend on QSO luminosity. Assuming a range of relations which relate halo to black hole mass, we investigate how black hole mass correlates with luminosity and redshift, and ascertain the relation between Eddington efficiency and black hole mass. Our results suggest that QSOs of different luminosities may contain black holes of similar mass.