阿塔卡马宇宙学望远镜:来自2008年功率谱的宇宙学参数
摘要
我们给出了由阿塔卡马宇宙学望远镜(ACT)在2008年观测季期间,于148 GHz和218 GHz频率下在296 deg^2天区观测到的宇宙微波背景(CMB)辐射角功率谱推导出的宇宙学参数。ACT测量了尺度500<l<10000的涨落。我们对148 GHz和218 GHz功率谱拟合了包含引力透镜CMB、Sunyaev-Zel'dovich (SZ) 效应和前景贡献的模型,包括热SZ和动力学SZ、来自射电和红外点源的泊松功率,以及来自红外点源的成团功率。148 GHz处热SZ和动力学SZ的功率估计为 B_3000 = 6.8+-2.9 uK^2,其中 B_l=l(l+1)C_l/2pi。我们在对SZ和源功率参数进行边缘化后,从148 GHz谱估计了初级宇宙学参数。LCDM宇宙学模型对数据拟合良好,且由ACT+WMAP估计的LCDM参数与7年WMAP极限一致,其中标度不变的 n_s = 1 在99.7% CL (3sigma) 被排除。无CMB引力透镜的模型在2.8sigma被排除。通过测量第三至第七声学峰,并探测Silk阻尼区,ACT数据改进了影响小尺度CMB功率的宇宙学参数的极限。ACT数据结合WMAP给出了对原初氦的6sigma探测,Y_P = 0.313+-0.044,以及对相对论性物种(假设为中微子)的4sigma探测,Neff = 5.3+-1.3(结合BAO+H0数据为4.6+-0.8)。仅从CMB来看,谱指数的跑动被约束为dn/dlnk = -0.034 +- 0.018,张标比极限为r<0.25 (95% CL),Nambu宇宙弦对功率谱的可能贡献被约束为弦张力 Gmu<1.6 \times 10^-7 (95% CL)。
引用
@article{arxiv.1009.0866,
title = {The Atacama Cosmology Telescope: Cosmological Parameters from the 2008 Power Spectra},
author = {J. Dunkley and R. Hlozek and J. Sievers and V. Acquaviva and P. A. R. Ade and P. Aguirre and M. Amiri and J. W. Appel and L. F. Barrientos and E. S. Battistelli and J. R. Bond and B. Brown and B. Burger and J. Chervenak and S. Das and M. J. Devlin and S. R. Dicker and W. Bertrand Doriese and R. Dunner and T. Essinger-Hileman and R. P. Fisher and J. W. Fowler and A. Hajian and M. Halpern and M. Hasselfield and C. Hernandez-Monteagudo and G. C. Hilton and M. Hilton and A. D. Hincks and K. M. Huffenberger and D. H. Hughes and J. P. Hughes and L. Infante and K. D. Irwin and J. B. Juin and M. Kaul and J. Klein and A. Kosowsky and J. M Lau and M. Limon and Y-T. Lin and R. H. Lupton and T. A. Marriage and D. Marsden and P. Mauskopf and F. Menanteau and K. Moodley and H. Moseley and C. B Netterfield and M. D. Niemack and M. R. Nolta and L. A. Page and L. Parker and B. Partridge and B. Reid and N. Sehgal and B. Sherwin and D. N. Spergel and S. T. Staggs and D. S. Swetz and E. R. Switzer and R. Thornton and H. Trac and C. Tucker and R. Warne and E. Wollack and Y. Zhao},
journal= {arXiv preprint arXiv:1009.0866},
year = {2015}
}
备注
20 pages, 13 figures. Submitted to ApJ. This paper is a companion to Hajian et al. (2010) and Das et al. (2010)