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arXiv 1010.0491astro-ph.CO
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近红外背景起伏的AKARI观测

AKARI observation of the fluctuation of the near-infrared background

T. Matsumoto, H. J. Seo, W. -S. Jeong, H. M. Lee, S. Matsuura, H. Matsuhara, S. Oyabu, J. Pyo, T. Wada

摘要:

我们报告了日本红外天文卫星AKARI在2.4、3.2和4.1 \mum上对朝向北黄道极(NEP)的天空亮度波动的搜索。我们得到了圆形地图与100直径的视野,清楚地显示了空间结构的规模为几百弧秒。功率谱分析表明,在大于10000的角尺度上,存在一个明显的过剩涨落,这不能用黄道光、漫射银河光、暗星系的散粒噪声或低红移星系团来解释。这些结果与美国宇航局斯皮策太空望远镜在3.6和4.5 \mum的观测结果一致。在大角度尺度下观测到的波动分量具有蓝色恒星光谱,这与IRTS观测到的过量各向同性发射光谱相似。波段间存在显著的空间相关性,线性相关的斜率与超涨落谱一致。这些发现表明,探测到的波动可以归因于宇宙的第一批恒星,即pop.III恒星。观测到的涨落对第一颗恒星的时代提供了重要的限制。

英文摘要:

We report a search for fluctuations of the sky brightness toward the north ecliptic pole (NEP) with the Japanese infrared astronomical satellite AKARI,at 2.4, 3.2, and 4.1 \mum. We obtained circular maps with 100 diameter field of view which clearly show a spatial structure on scale of a few hundred arcsec. A power spectrum analysis shows that there is a significant excess fluctuation at angular scales larger than 10000 that can't be explained by zodiacal light, diffuse Galactic light, shot noise of faint galaxies or clustering of low redshift galaxies. These results are consistent with observations at 3.6 and 4.5 \mum by NASA's Spitzer Space Telescope. The fluctuating component observed at large angular scales has a blue stellar spectrum which is similar to that of the spectrum of the excess isotropic emission observed with IRTS. A significant spatial correlation between wavelength bands was found, and the slopes of the linear correlations is consistent with the spectrum of the excess fluctuation. These findings indicate that the detected fluctuation could be attributed to the first stars of the universe, i.e. pop. III stars. The observed fluctuation provides an important constraints on the era of the first stars.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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