ON THE DETECTION OF SPECTRAL RIPPLES FROM THE RECOMBINATION EPOCH
ON THE DETECTION OF SPECTRAL RIPPLES FROM THE RECOMBINATION EPOCH
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复合时期光谱波纹的检测
DOI：
10.1088/0004-637x/810/1/3
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
J. Chluba
中科院分区：
文献类型：
--
作者：
M. S. Rao;M. S. Rao;R. Subrahmanyan;N. Shankar;J. Chluba
宇宙氢（500赫兹至1600赫兹））和氦复合（1600？因为他二？”他我，5000美元，8000美元？>“他三？”氦ii）被预测为宇宙微波背景辐射的宽而弱的光谱畸变。我们提出了一个可行性研究的地面探测这些复合线，这将是唯一的探测天体物理宇宙学超越了最后的散射表面，并提供观测约束宇宙的热历史。我们发现，包括足够的信号频谱结构和最大化的信噪比，在2-6 GHz窗口的倍频程频带是最佳的，在这个频带中的预测信号出现作为一个附加的准正弦分量与振幅约8 nK嵌入在天空光谱一些9个数量级明亮。我们讨论的算法来检测这些微小的光谱波动的天空光谱的前景建模，并引入一个最大的平滑函数能够描述的前景光谱和区分感兴趣的信号。我们的结论是，检测在原则上是可行的，在现实的观测时间提供的无线电频率干扰和仪器带通校准控制在这个波段在所需的水平，使用贝叶斯测试和模拟数据，我们表明，90%的置信度检测是可能的，128个辐射计的阵列观察255天的有效集成时间。我们建议APSERa-阵列精密光谱仪的时代，一个专门的射电望远镜来检测这些复合线。
Photons emitted during cosmological hydrogen ( 500 ≲ z ≲ 1600 ?> ) and helium recombination ( 1600 ≲ z ≲ 3500 ?> for He ii → ?> He i, 5000 ≲ z ≲ 8000 ?> for He iii → ?> He ii) are predicted to appear as broad, weak spectral distortions of the cosmic microwave background. We present a feasibility study for a ground-based detection of these recombination lines, which would uniquely probe astrophysical cosmology beyond the last scattering surface and provide observational constraints on the thermal history of the universe. We find that including sufficient signal spectral structure and maximizing signal-to-noise ratio, an octave band in the 2–6 GHz window is optimal; in this band the predicted signal appears as an additive quasi-sinusoidal component with amplitude about 8 nK embedded in a sky spectrum some nine orders of magnitude brighter. We discuss algorithms to detect these tiny spectral fluctuations in the sky spectrum by foreground modeling and introduce a maximally smooth function capable of describing the foreground spectrum and distinguishing the signal of interest. We conclude that detection is in principle feasible in realistic observing times provided that radio frequency interference and instrument bandpass calibration are controlled in this band at the required level; using Bayesian tests and mock data, we show that 90% confidence detection is possible with an array of 128 radiometers observing for 255 days of effective integration time. We propose APSERa—Array of Precision Spectrometers for the Epoch of Recombination—a dedicated radio telescope to detect these recombination lines.
影响因子：
6.4
作者：
Prism Collaboration Philippe Andr'e;C. Baccigalupi;A. Banday;D. Barbosa;B. Barreiro;J. Bartlett;N. Bart
通讯作者：
Prism Collaboration Philippe Andr'e;C. Baccigalupi;A. Banday;D. Barbosa;B. Barreiro;J. Bartlett;N. Bart
旋转尘埃辐射的改进模型
DOI：
10.1111/j.1365-2966.2009.14599.x
发表时间：
2009
影响因子：
4.8
作者：
Ali-Haïmoud Y
通讯作者：
Ali-Haïmoud Y