Untangling dust emission and cosmic infrared background anisotropies with the scattering transform statistics
National Institute of Science Education and Research（印度科学教育研究所）；Homi Bhabha National Institute（霍米·巴巴国立研究所）；Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité（巴黎高等师范学院物理实验室）；Laboratoire d’Océanographie Physique et Spatiale (LOPS), Univ. Brest, CNRS, Ifremer, IRD（布列斯特大学海洋物理与空间实验室）
Srijita Sinha, Tuhin Ghosh, Erwan Allys, François Boulanger, Jean-Marc Delouis
备注：
16 pages; 26 figures; To appear in the Forthcoming section of Astronomy & Astrophysics (A&A)
模板拟合方法常用于在低HI柱密度区域将银河系尘埃辐射与宇宙红外背景（CIB）各向异性分离，前提是气体和尘埃紧密相关。然而，该方法在存在分子氢、弥散电离气体和暗气体等额外银河系辐射的区域失效。我们开发并测试了一种统计成分分离方法，利用散射协方差（SC）统计从受污染的Planck 353 GHz观测中提取尘埃信号。我们首先通过模板拟合方法，利用尘埃与银河系21 cm HI发射之间的线性相关性（在低HI柱密度区域有效），在25个面积为222 deg²的方形天区上获得一组CIB图。然后，我们利用SC统计从这25张图中构建CIB的生成模型。最后，我们依赖该污染模型对不同天区的Planck数据进行尘埃和CIB的成分分离。将算法应用于Planck 353 GHz观测，我们在测试天区恢复的尘埃图比100 μm的校正SFD图展现出更多结构。通过将恢复的Planck尘埃图分解为两个气体相（与N_HI相关的尘埃和与N_H2相关的尘埃），可以解释图层面观察到的差异。这项工作为在银河系中高纬度区域绘制星际红化提供了清晰的路径。
英文摘要：
The template-fit approach is often used to separate Galactic dust emission from cosmic infrared background (CIB) anisotropies in low $\text{HI}$ column density regions, under the assumption that gas and dust are tightly correlated. However, this method fails in regions where additional Galactic emission from molecular hydrogen, diffuse ionized gas, and dark gas is present. We develop and test a statistical component-separation method to extract the dust signal from contaminated $\textit{Planck}$ $353\,\rm GHz$ observations using Scattering Covariance (SC) statistics. We first obtain a set of CIB maps over $25$ square patches, each covering an area of $222\,{\rm deg}^{2}$, using the linear correlation between dust and Galactic $21\,\rm cm$ $\text{HI}$ emission, which is valid in low $\text{HI}$ column density regions, through the template-fit approach. We then construct, from these $25$ maps, a generative model of the CIB using SC statistics. Finally, we rely on this contamination model to perform component separation of dust and CIB in the $\textit{Planck}$ data for different sky regions. Applying our algorithm to the $\textit{Planck}$ $353\,\rm GHz$ observations, we recover a dust map for a test sky region that exhibits more structure than the corrected SFD map at $100\,μ\rm m$. The differences observed at the map level can be explained by decomposing the recovered $\textit{Planck}$ dust map into two gas phases: dust associated with $N_{\text{HI}}$ and dust associated with $N_{\text{H}_{2}}$. This work provides a clear pathway for mapping Galactic interstellar reddening over intermediate and high Galactic latitudes.
We present a method to self-consistently propagate M$_{*}$ and SFR ($Ψ$) uncertainties onto intercept, slope and intrinsic scatter estimates for a simple model of the main sequence of star forming galaxies where $Ψ= α+ β$M$_{*} + \mathcal{N}(0,σ)$. From simple idealised models set up with broad-band photometry from NIRCam filters at $z\sim5$, we test the method and compare to methods in the literature. Simplifying the $Ψ$ estimate by basing it on dust-corrected MUV can help to reduce the impact of template set degeneracies on slope and intercept estimates, but act to bias the intrinsic scatter…
Revealing Galactic dust beneath the cosmic infrared background anisotropies with Wavelet Phase Harmonics
School for Physical Sciences, National Institute of Science Education and Research（国立科学教育与研究学院物理科学学院）；Homi Bhabha National Institute（霍米·巴巴国立研究所）；Raman Research Institute（拉曼研究所）；Laboratoire de Physique de l’École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité（巴黎高等师范学院物理实验室）；Laboratoire d’Océanographie Physique et Spatiale (LOPS), Univ. Brest, CNRS, Ifremer, IRD（物理与空间海洋学实验室）
We use analytic computations to predict the power spectrum as well as the bispectrum of Cosmic Infrared Background (CIB) anisotropies. Our approach is based on the halo model and takes into account the mean luminosity-mass relation. The model is used to forecast the possibility to simultaneously constrain cosmological, CIB and halo occupation distribution (HOD) parameters in the presence of foregrounds. For the analysis we use wavelengths in eight frequency channels between 200 and 900$\;\mathrm{GHz}$ with survey specifications given by Planck and LiteBird. We explore the sensitivity to the mo…
Component separation for the Planck HFI data is primarily concerned with the estimation of thermal dust emission, which requires the separation of thermal dust from the cosmic infrared background (CIB). For that purpose, current estimation methods rely on filtering techniques to decouple thermal dust emission from CIB anisotropies, which tend to yield a smooth, low- resolution, estimation of the dust emission. In this paper we present a new parameter estimation method, premise: Parameter Recovery Exploiting Model Informed Sparse Estimates. This method exploits the sparse nature of thermal dust…
We present a linear clustering model of cosmic infrared background (CIB) anisotropies at large scales that is used to measure the cosmic star formation rate density up to redshift 6, the effective bias of the CIB and the mass of dark-matter halos hosting dusty star-forming galaxies. This is achieved using the Planck CIB auto- and cross-power spectra (between different frequencies) and CIBxCMB lensing cross-spectra measurements, as well as external constraints (e.g. on the CIB mean brightness). We recovered an obscured star formation history which agrees well with the values derived from infrar…
Here, we report ALMA detections of polarized emission from dust, CS($J=5 \rightarrow 4$), and C$^{33}$S($J=5 \rightarrow 4$) toward the high-mass star-forming region NGC6334I(N). A clear ``hourglass'' magnetic field morphology was inferred from the polarized dust emission which is also directly seen from the polarized CS emission across velocity, where the polarization appears to be parallel to the field. By considering previous findings, the field retains a pinched shape which can be traced to clump length-scales from the envelope scales traced by ALMA, suggesting that the field is dynamicall…
