论文标题
宇宙光学背景的新视野观察
New Horizons Observations of the Cosmic Optical Background
论文作者
论文摘要
我们使用了新的Horizons Lorri相机中的现有数据来测量光带（$ 0.4 \Lessimλ\ Lessimsim0.9 {\rmμm} $）在七个高银河纬度字段中的天空亮度。在新的视野为42至45 au时测量的平均原始水平为$ 33.2 \ pm0.5 {\ rm〜nw〜m^{ - 2} 〜sr^{ - 1}}。宇宙光学背景（COB）。隔离对原始总数的COB贡献需要从明亮的恒星和星系，田间的光度检测限制下的微弱恒星中减去散射的光，以及弥漫的银河系光，由红外黄卷散射。我们从虹膜$100μ$ m的所有天空图中删除了新鉴定的残留黄道带，以产生两个不同的估计，用于弥漫性银河光（DGL）。使用这些产量在$ {\ rm 15.9 \ pm 4.2 \（1.8〜STAT。，3.7〜SYS。）〜NW〜M^{ - 2} 〜Sr^{ - 1}} $至$ {\ rm 18.7 \ pm 3.8 \ pm 3.8 \（1.8〜Stys）中。 〜sr^{ - 1}} $在Lorri枢轴波长为0.608 $μ$ m。与来自总COB的光度检测限制相比，星系综合光（IGL）的逐步减法在$ {\ rm 8.8 \ pm4.9 \（1.8〜STAT。 11.9 \ pm4.6 \（1.8〜STAT。，4.2〜SYS。）〜NW〜M^{ - 2} 〜Sr^{ - 1}} $。用未检测到的星系解释这一点，需要星系计数的微弱端坡度在$ v> 24 $中显着陡峭，或者现有的调查缺少一半的星系，$ v <30。$ $
We used existing data from the New Horizons LORRI camera to measure the optical-band ($0.4\lesssimλ\lesssim0.9{\rmμm}$) sky brightness within seven high galactic latitude fields. The average raw level measured while New Horizons was 42 to 45 AU from the Sun is $33.2\pm0.5{\rm ~nW ~m^{-2} ~sr^{-1}}.$ This is $\sim10\times$ darker than the darkest sky accessible to the {\it Hubble Space Telescope}, highlighting the utility of New Horizons for detecting the cosmic optical background (COB). Isolating the COB contribution to the raw total requires subtracting scattered light from bright stars and galaxies, faint stars below the photometric detection-limit within the fields, and diffuse Milky Way light scattered by infrared cirrus. We remove newly identified residual zodiacal light from the IRIS $100μ$m all sky maps to generate two different estimates for the diffuse galactic light (DGL). Using these yields a highly significant detection of the COB in the range ${\rm 15.9\pm 4.2\ (1.8~stat., 3.7~sys.) ~nW ~m^{-2} ~sr^{-1}}$ to ${\rm 18.7\pm 3.8\ (1.8~stat., 3.3 ~sys.)~ nW ~m^{-2} ~sr^{-1}}$ at the LORRI pivot wavelength of 0.608 $μ$m. Subtraction of the integrated light of galaxies (IGL) fainter than the photometric detection-limit from the total COB level leaves a diffuse flux component of unknown origin in the range ${\rm 8.8\pm4.9\ (1.8 ~stat., 4.5 ~sys.) ~nW ~m^{-2} ~sr^{-1}}$ to ${\rm 11.9\pm4.6\ (1.8 ~stat., 4.2 ~sys.) ~nW ~m^{-2} ~sr^{-1}}$. Explaining it with undetected galaxies requires the galaxy-count faint-end slope to steepen markedly at $V>24$ or that existing surveys are missing half the galaxies with $V< 30.$
