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arXiv 1102.2251astro-ph.CO
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Sloan数字巡天亮红星系二维两点关联函数测量H(z)和D_A(z)

Measurements of H(z) and D_A(z) from the Two-Dimensional Two-Point Correlation Function of Sloan Digital Sky Survey Luminous Red Galaxies

Chia-Hsun Chuang, Yun Wang

摘要:

本文提出了一种从二维两点关联函数测量哈勃参数H(z)和角直径距离D_A(z)的方法,并用LasDamas模拟星系表进行了验证。在没有假设宇宙是一个暗能量模型或平坦宇宙的情况下,我们将我们的方法应用于斯隆数字巡天(SDSS)数据发布7(DR 7)中的亮红星系(LRGs)样本,测量了H(z=0.35)=82.1 - 4.9}^{+4.8} km s^{-1}Mpc^{-1},DA(z=0.35)=1048 - 58}^{+60} Mpc.我们发现H(0.35)rs(z_d)/c和D_A(0.35)/rs(z_d)(其中rs(z_d)是拖曳期的声水平线)的测量值几乎不相关,有更严格的约束,并且对可能的系统效应更稳健。我们的星系团测量值{H(0.35)r_s(z_d)/c,D_A(0.35)/r_s(z_d)}={0.0434 \pm 0.0018,6.60 \pm 0.26}(相关系数r = 0.0604),可以用来结合宇宙微波背景和任何其他宇宙学数据来约束暗能量。我们的结果代表了星系团数据中H(z)和D_A(z)(或H(z)r_s(z_d)/c和D_A(0.35)/r_s(z_d))的首次测量。我们的工作对未来的研究具有重要的意义,可以从星系团数据中确定测量H(z)和D_A(z)的可行性。

英文摘要:

We present a method for measuring the Hubble parameter, H(z), and angular diameter distance, D_A(z), from the two-dimensional two-point correlation function, and validate it using LasDamas mock galaxy catalogs. Applying our method to the sample of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7), we measure H(z=0.35)=82.1_{-4.9}^{+4.8} km s^{-1}Mpc^{-1}, D_A(z=0.35)=1048_{-58}^{+60} Mpc without assuming a dark energy model or a flat Universe. We find that the derived measurements of H(0.35)r_s(z_d)/c and D_A(0.35)/r_s(z_d) (where r_s(z_d) is the sound horizon at the drag epoch) are nearly uncorrelated, have tighter constraints and are more robust with respect to possible systematic effects. Our galaxy clustering measurements of {H(0.35)r_s(z_d)/c, D_A(0.35)/r_s(z_d)}={0.0434\pm 0.0018,6.60\pm 0.26} (with the correlation coefficient r = 0.0604) can be used to combine with cosmic microwave background and any other cosmological data sets to constrain dark energy. Our results represent the first measurements of H(z) and D_A(z) (or H(z)r_s(z_d)/c and D_A(0.35)/r_s(z_d)) from galaxy clustering data. Our work has significant implications for future surveys in establishing the feasibility of measuring both H(z) and D_A(z) from galaxy clustering data.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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