论文标题
大规模过剩的证据与Sky $$ \\ $$ I中的低HI柱密度相关。灰尘过多
Evidence for large-scale excesses associated with low HI column densities in the sky $$\\$$I. Dust excess
论文作者
论文摘要
在灰尘和气体均匀混合的地方，可以通过检测远红外（FIR）或粉尘的紫外线排放来追溯原子氢。我们认为，对于银河平面外的各种直接和间接气体示踪剂之间观察到的差异的起源，可能会校正Planck-HFI检测器的零水平。我们将Planck高频仪器（HFI）Skymap的零级以及来自Cobe/dirbe的100 $ $ m映射以及来自FIR发射和原子氢柱密度之间的相关性的IRA，不包括最低气柱密度的区域。 A modified blackbody model fit to those new zero-subtracted maps led to significantly different maps of the opacity spectral index $β$ and temperature $T$ and an overall increase in the optical depth at 353 GHz $τ_{353}$ of 7.1$\times$10$^{-7}$ compared to the data release 2 Planck map.在比较$τ_{353} $和HI柱密度时，我们观察到具有深中性气和CO的不透明度区域外部的空间分布，除了在各种低NHI的大型区域，代表了天空的25％。在这些区域，我们观察到平均灰尘柱密度比基于NHI的预测高45％，对洛克曼孔区域的最高为250％。从平均不透明度$σ_{我们没有看到与电离氢的雷诺层相关的灰尘的证据。我们测量了一个远 - 硫酸的各向同性强度为137 $ \ pm $ 15光子S $^{ - 1} $ cm $ $^{ - 2} $ sr $^{ - 1} $ a $ a $ a $ a $ a $ a $ a $ a $ a $ a $ a $^{ - 1} s $^{ - 1} $ cm $^{ - 2} $ sr $^{ - 1} $$ a $$ a $$^{ - 1} $对应于两次预测的通量。
Where dust and gas are uniformly mixed, atomic hydrogen can be traced through the detection of far-infrared (FIR) or UV emission of dust. We considered, for the origin of discrepancies observed between various direct and indirect tracers of gas outside the Galactic plane, possible corrections to the zero levels of the Planck-HFI detectors. We set the zero levels of the Planck High Frequency Instrument (HFI) skymaps as well as the 100 $μ$m map from COBE/DIRBE and IRAS from the correlation between FIR emission and atomic hydrogen column density excluding regions of lowest gas column density. A modified blackbody model fit to those new zero-subtracted maps led to significantly different maps of the opacity spectral index $β$ and temperature $T$ and an overall increase in the optical depth at 353 GHz $τ_{353}$ of 7.1$\times$10$^{-7}$ compared to the data release 2 Planck map. When comparing $τ_{353}$ and the HI column density, we observed a uniform spatial distribution of the opacity outside regions with dark neutral gas and CO except in various large-scale regions of low NHI that represent 25% of the sky. In those regions, we observed an average dust column density 45% higher than predictions based on NHI with a maximum of 250% toward the Lockman Hole region. From the average opacity $σ_{e 353}$=(8.9$\pm$0.1)$\times$10$^{-27}$ cm$^2$ we deduced a dust-to-gas mass ratio of 0.53$\times$10$^{-2}$. We did not see evidence of dust associated to a Reynolds layer of ionized hydrogen. We measured a far-ultraviolet isotropic intensity of 137$\pm$15 photons s$^{-1}$cm$^{-2}$sr$^{-1}$$A$$^{-1}$ in agreement with extragalactic flux predictions and a near-ultraviolet isotropic intensity of 378$\pm$45 photons s$^{-1}$cm$^{-2}$sr$^{-1}$$A$$^{-1}$ corresponding to twice the predicted flux.
