局部原始非高斯性的约束与动力苏尼亚耶夫-泽尔多维奇效应的3D速度重建
Alex Laguë1, Mathew S Madhavacheril1, Kendrick M Smith2
1University of Pennsylvania, Department of Physics and Astronomy, 209 South 33rd Street, Philadelphia, Pennsylvania, USA 19104.
Physical review letters
|May 2, 2025
概括
科学家们使用来自宇宙微波背景 (CMB) 数据的动力苏尼亚耶夫-泽尔多维奇 (kSZ) 效应重建了宇宙速度场. 这种新的方法为原始非高斯性提供了新的约束.
科学领域:
- 宇宙学的宇宙学是什么?
- 天体物理学 天体物理学
- 一个大规模的结构结构.
背景情况:
- 宇宙速度场追踪了总物质分布,但在高红移时很难直接测量.
- 动力苏尼亚耶夫-泽尔多维奇 (kSZ) 效应将大规模的速度场印在宇宙微波背景 (CMB) 上.
研究的目的:
- 使用kSZ效应,进行大规模速度场的第一个3D重建.
- 为了限制宇宙学参数,特别是原始非高斯性 (f_NL).
主要方法:
- 将二次估计器应用于CMB温度图和3D星系位置.
- 联合阿塔卡马宇宙望远镜 (ACT) 和普朗克CMB数据与斯隆数字天空调查 (SDSS) 银河系数据.
- 测量了银河系速度交叉功率频谱以检测kSZ信号.
主要成果:
- 在星系速度交叉相关性中成功检测到kSZ信号,信号与噪声比为7.2σ.
- 仅使用这种交叉相关性,将局部原始非高斯性幅度限制为f_NL = -90_{-350}^{+210}.
结论:
- 这种探路器测量表明了结合星系和CMB kSZ数据的潜力.
- 未来的联合分析可以通过减轻样本差异来显著改善f_NL的约束.
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