标题： 再电离时代合成图像中明亮点源的减法 显示英文标题

标题： Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization

摘要： 明亮的点源与河外AGN和射电星系相关，是低频射电实验的重要前景，这些实验旨在检测再电离时期中性氢的红移21厘米发射。合成波束的频率依赖性意味着这些源的旁瓣将随着观测频率的变化而在视场内移动，因此会干扰视线前景减除技术。我们描述了一种从如MWA这样的仪器产生的脏图中减去这些点源的方法。该技术结合匹配滤波器与迭代质心方案，在存在弥散背景的情况下定位和表征点源。模拟显示，该技术可以将EOR图的动态范围提高2-3个数量级。 显示英文摘要

摘要： Bright point sources associated with extragalactic AGN and radio galaxies are an important foreground for low frequency radio experiments aimed at detecting the redshifted 21cm emission from neutral hydrogen during the epoch of reionization. The frequency dependence of the synthesized beam implies that the sidelobes of these sources will move across the field of view as a function of observing frequency, hence frustrating line-of-sight foreground subtraction techniques. We describe a method for subtracting these point sources from dirty maps produced by an instrument such as the MWA. This technique combines matched filters with an iterative centroiding scheme to locate and characterize point sources in the presence of a diffuse background. Simulations show that this technique can improve the dynamic range of EOR maps by 2-3 orders of magnitude.