论文标题
搜索Fermi-lat漫射$γ$ -Ray地图的集成Sachs-Wolfe效应
Searching for Integrated Sachs-Wolfe Effect from Fermi-LAT Diffuse $γ$-ray Map
论文作者
论文摘要
在本文中，我们估算了Planck 2018宇宙微波背景（CMB）温度各向异性图与未解决的$γ$ -Ray背景（UGRB）之间的互相关功率光谱。在此分析中，我们在Fermi-LAT UGRB数据的[0.631，1000] GEV的广泛能量范围内最多使用了9个能量箱。首先，我们发现具有能量范围[1.202，2.290] GEV和[17.38，36.31] GEV的FERMI数据显示了集成的Sachs-Wolfe（ISW）效应的积极证据，其置信度为$1.8σ$，并且在使用这两个能源量子时的意义将增加到2.7σ$。其次，我们使用单个幂律模型来归一化振幅并使用所有九个费米能量箱来衡量ISW效应的重要性，我们获得了$ {\ rm a_ {amp}} = 0.95 \ pm 0.53 $（$ 68 \％\％$ c.l.）。对于鲁棒性测试，我们通过将9个能量箱的费米模拟图随机化，并获得ISW效应的未检测，这证实ISW信号来自Fermi-LAT扩散$γ$ ray数据，并且与标准的$λ$ CDM模型一致。我们使用互相关系数来显示不同能量箱之间的关系。此外，我们在费米地图的面罩上改变了切割范围的$ | b | $，并仔细检查随后对ISW信号检测的影响。
In this paper, we estimate the cross-correlation power spectra between the Planck 2018 cosmic microwave background (CMB) temperature anisotropy map and the unresolved $γ$-ray background (UGRB) from the 9-years Fermi-Large Area Telescope (LAT) data. In this analysis, we use up to nine energy bins over a wide energy range of [0.631, 1000] GeV from the Fermi-LAT UGRB data. Firstly, we find that the Fermi data with the energy ranges [1.202, 2.290] GeV and [17.38, 36.31] GeV show the positive evidence for the Integrated Sachs-Wolfe (ISW) effect at $1.8σ$ confidence level, and the significance would be increased to $2.7σ$ when using these two energy bins together. Secondly, we apply the single power-law model to normalize the amplitude and use all the nine Fermi energy bins to measure the significance of the ISW effect, we obtained ${\rm A_{amp}}=0.95 \pm 0.53$ ($68\%$ C.L.). For the robustness test, we implement a null hypothesis by randomizing the Fermi mock maps of nine energy bins and obtain the non-detection of ISW effect, which confirms that the ISW signal comes from the Fermi-LAT diffuse $γ$-ray data and is consistent with the standard $Λ$CDM model prediction essentially. We use a cross-correlation coefficient to show the relation between different energy bins. Furthermore, we vary the cut ranges $|b|$ of galactic plane on the mask of Fermi map and carefully check the consequent influence on the ISW signal detection.
