Carbon monoxide line emission as a CMB foreground: tomography of the star-forming universe with different spectral resolutions
Carbon monoxide line emission as a CMB foreground: tomography of the star-forming universe with different spectral resolutions
复制标题
作为 CMB 前景的一氧化碳线发射：具有不同光谱分辨率的恒星形成宇宙的断层扫描
DOI：
10.1051/0004-6361:200810199
复制
发表时间：
2008
影响因子：
6.5
通讯作者：
R. Sunyaev
中科院分区：
文献类型：
--
作者：
M. Righi;C. Hernandez;R. Sunyaev
语境。在宇宙中恒星形成增强时期释放出的一氧化碳的旋转线以及 CII 和最丰富金属的精细结构线，在当前和未来 CMB 实验敏感的频率通道中发生红移。目标。我们估计了合并恒星形成星系中此类谱线的发射对宇宙微波背景角功率谱的贡献。方法。我们使用莱西-科尔方法来表征合并晕的分布，以及每个合并晕中恒星形成率的参数化。使用来自本地、低红移和高红移天体样本的观测数据，我们将每条线的光度校准为恒星形成率的函数。结果。我们表明，CO 线发射产生的相关项是 CMB 在广泛频率范围内（特别是在 20−60 GHz 频段）和 1000 < l < 8000 的前景的重要来源，对应于小于 10 arcmin 的角尺度。此外，我们证明，用不同的光谱分辨率进行观察将有可能将信号的振幅增加到 Cl 的两个数量级，并将有助于将谱线贡献与几乎所有其他前景源和主要波动本身分开，因为这些对光谱分辨率没有显着的依赖性。结论。我们建议通过探测不同厚度的不同红移切片，以不同的光谱带宽（10 −3 < Δν/νobs < 10 −1 ）进行观测，作为构建宇宙断层扫描的新工具。这应该会对宇宙中负责金属富集的区域及其聚类模式产生新的约束，并将导致有关再电离时代和宇宙学参数（包括 σ8）的新提示。
Context. The rotational lines of carbon monoxide and the fine structure lines of CII and of the most abundant metals, emitted during the epoch of enhanced star formation in the universe, are redshifted in the frequency channels where the present-day and future CMB experiments are sensitive. Aims. We estimate the contribution to the CMB angular power spectrum by the emission in such lines in merging star-forming galaxies. Methods. We used the Lacey-Cole approach to characterize the distribution of the merging halos, together with a parametrization for the star formation rate in each of them. Using observational data from a sample of local, low-redshift, and high-redshift objects, we calibrated the luminosity in each line as a function of the star formation rate. Results. We show that the correlation term arising from CO line emission is a significant source of foreground for CMB in a broad range of frequencies (in particular in the 20−60 GHz band) and for 1000 < l < 8000, corresponding to angular scales smaller than 10 arcmin. Moreover, we demonstrate that observing with different spectral resolutions will give the possibility of increasing the amplitude of the signal up to two orders of magnitude in Cl and will help separate the line contribution from practically all other foreground sources and from the primary fluctuations themselves, since these show no significant dependence on the spectral resolution. Conclusions. We propose to perform observations with varying spectral bandwidths (10 −3 < Δν/νobs < 10 −1 ) as a new tool to construct a tomography of the universe, by probing different redshift slices with varying thickness. This should yield new constraints on the regions responsible for the metal enrichment in the universe and on their clustering pattern and will lead to new hints about the reionization epoch and the cosmological parameters, including σ8.