Combining Wilkinson Microwave Anisotropy Probe and Sloan Digital Sky Survey Quasar Data on Reionization Constrains Cosmological Parameters and Star Formation Efficiency
Combining Wilkinson Microwave Anisotropy Probe and Sloan Digital Sky Survey Quasar Data on Reionization Constrains Cosmological Parameters and Star Formation Efficiency
复制标题
结合威尔金森微波各向异性探测器和斯隆数字巡天类星体数据再电离约束宇宙学参数和恒星形成效率
DOI：
10.1086/379318
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
J. Ostriker
中科院分区：
文献类型：
--
作者：
W. Chiu;Xiaohui Fan;J. Ostriker
我们基于威尔金森微波各向异性探测器（WMAP）和斯隆数字巡天（SDSS）的高红移类星体的结合观测，提出了对宇宙学和恒星形成参数的限制。我们使用半解析模型进行再电离，该模型考虑了坍缩晕圈（例如氢气冷却）和星系间介质（例如氢气冷却、康普顿冷却和光电离加热）中的许多重要物理过程。我们发现，Gunn-Peterson 吸收数据以类似于从团簇质量函数导出的方式，对小尺度的功率谱提供了严格的约束。假设每个重子产生紫外光子的效率是恒定的，则在 h = 0.72、n = 0.99 和 Ωbh2 = 0.024 的平坦、Λ 主导的宇宙中，约束采用 σ8Ω ≈ 0.33 的形式。然而，计算出的电子散射光学深度 τes ~ 0.06 远低于 WMAP 发现的值 0.17 ± (0.04 ~ 0.07)。由于 τes 上的 WMAP 约束在一定程度上随频谱指数 n 的值而退化，因此我们允许原始频谱指数 n 浮动，并考虑仅 1 σ WMAP 确定 Ω0h2 = 0.14 ± 0.02（意味着 Ω0 = 0.27 ± 0.04），同时使用 WMAP 对功率谱进行归一化。另外，我们过去允许UV效率更大。将 WMAP 约束与类星体传输数据相结合，我们的分析倾向于采用 τes = 0.11(Ω0/0.27)-1、n = 0.96(Ω0/0.27)-0.57 的模型，这意味着 WMAP 归一化为 σ8 = 0.83(Ω0/0.27)0.53（均为 95% 置信度），有效 UV 效率至少为z ≫ 6 时约为 10 倍。对于恒星来说，隐含的 UV 效率并非不合理，范围从 10-5.5 到 10-4。这些结果表明类星体和 WMAP 观测结果是一致的。如果未来的观测证实电子散射光学深度τes ~ 0.1，那么似乎不再需要“奇异”的紫外光子源，例如微型类星体或活动星系核。然而，除非考虑更激进的紫外光子源或密度涨落功率谱的替代形式，否则在不违反 z = 4 至 6 类星体传输数据和大尺度 WMAP 测量的某些约束组合的情况下，无法实现 τes ≳ 0.17 的值。
We present constraints on cosmological and star formation parameters based on combining observations from the Wilkinson Microwave Anisotropy Probe (WMAP) and high-redshift quasars from the Sloan Digital Sky Survey (SDSS). We use a semianalytic model for reionization that takes into account a number of important physical processes both within collapsing halos (e.g., H2 cooling) and in the intergalactic medium (e.g., H2 cooling, Compton cooling, and photoionization heating). We find that the Gunn-Peterson absorption data provide tight constraints on the power spectrum at small scales in a manner analogous to that derived from the cluster mass function. Assuming that the efficiency of producing UV photons per baryon is constant, the constraint takes on the form σ8Ω ≈ 0.33 in a flat, Λ-dominated universe with h = 0.72, n = 0.99, and Ωbh2 = 0.024. However, the calculated optical depth to electron scattering of τes ~ 0.06 is well below the value found by WMAP of 0.17 ± (0.04 ~ 0.07). Since the WMAP constraints on τes are somewhat degenerate with the value of the spectral index n, we then permit the primordial spectral index n to float and consider the 1 σ WMAP-only determination of Ω0h2 = 0.14 ± 0.02 (implying Ω0 = 0.27 ± 0.04), while normalizing the power spectrum using WMAP. In addition, we allow the UV efficiency to be greater in the past. Combining the WMAP constraints with the quasar transmission data, our analysis then favors a model with τes = 0.11(Ω0/0.27)-1, n = 0.96(Ω0/0.27)-0.57, implying a WMAP normalization of σ8 = 0.83(Ω0/0.27)0.53 (all at 95% confidence) and an effective UV efficiency that was at least ~10 times greater at z ≫ 6. The implied UV efficiency is not unreasonable for stars, spanning the range from 10-5.5 to 10-4. These results indicate that the quasar and WMAP observations are consistent. If future observations confirm an optical depth to electron scattering τes ~ 0.1, then it would appear that no more "exotic" sources of UV photons, such as miniquasars or active galactic nuclei, are necessary. However, unless one considers more radical sources of UV photons or alternative forms for the power spectrum of density fluctuations, one cannot achieve a value of τes ≳ 0.17 without violating some combination of constraints from quasar transmission data from z = 4 to 6 and WMAP measurements at large scales.
DOI：
10.1086/377225
发表时间：
2003-02
期刊：
The Astrophysical Journal Supplement Series
影响因子：
--
作者：
G. Hinshaw;D. Spergel;L. Verde;R. Hill;S. Meyer;C. Barnès;C. Bennett;M. Halpern;N. Jarosik;A. Kogut;E. Komatsu;M. Limon;L. Page;G. Tucker;J. Weiland;Edward J. Wollack;E. L. W. N. Gsfc;Princeton;Ssai;U. Chicago;Ubc;Brown;Ucla
通讯作者：
G. Hinshaw;D. Spergel;L. Verde;R. Hill;S. Meyer;C. Barnès;C. Bennett;M. Halpern;N. Jarosik;A. Kogut;E. Komatsu;M. Limon;L. Page;G. Tucker;J. Weiland;Edward J. Wollack;E. L. W. N. Gsfc;Princeton;Ssai;U. Chicago;Ubc;Brown;Ucla
影响因子：
8.7
作者：
Bennett, CL;Halpern, M;Weiland, JL
通讯作者：
Weiland, JL