In optical and near-infrared background light, excess brightness and fluctuation over the known backgrounds have been reported. To delineate their origin, a fluctuation analysis of the deepest optical images was performed, leading to the detection of a flat fluctuation down to 0.2 arcsec, which is much larger than that expected for galaxies. The sky brightness obtained from the detected fluctuation is a few-times brighter than the integrated light of the galaxies. These findings require some new objects. As a candidate, faint compact objects (FCOs) whose surface number density rapidly increases to the faint end were proposed. FCOs are very compact and show peculiar spectra with infrared excess. If FCOs cause the excess brightness and fluctuation, the surface number density reaches 2.6 × 10³ arcsec⁻². γ-ray observations require the redshift of FCOs to be less than 0.1 with FCOs consisting of missing baryons. A very low M/L indicates that FCOs are powered by gravitational energy associated with black holes.

在光学和近红外背景光中，已经报道了超过已知背景的过度亮度和波动。为了描述它们的起源，对最深的光学图像进行了波动分析，从而导致检测到低至0.2 arcsec的平坦波动，该波动远大于星系预期的波动。从检测到的涨落中获得的天空亮度比星系的综合光亮几倍。这些发现需要一些新的对象。作为候选，提出了表面数密度迅速增加到模糊末端的模糊致密物体（FCO）。FCO非常紧凑，并显示具有红外过量的特殊光谱。如果FCO导致过大的亮度和波动，则表面编号密度达到2.6×10 ³ arcsec⁻²。γ射线观测要求FCO的红移小于0.1，且FCO由缺失的重子组成。极低的M / L表示FCO由与黑洞相关的引力驱动。