论文标题
Lofar两米的天空调查：深领域，我 - 方向依赖的校准和成像
The LOFAR Two Meter Sky Survey: Deep Fields, I -- Direction-dependent calibration and imaging
论文作者
论文摘要
低频阵列（Lofar）是进行深层外层次调查的理想仪器。它具有很大的视野，并且对大规模和紧凑的发射敏感。但是，在完全分辨率下合成热噪声限制地图非常具有挑战性，这主要是由于低频天空的复杂性和方向依赖性效应（相位阵列梁和电离层）。在系列的第一篇论文中，我们提出了一种新的校准和成像管道，旨在用Lofar高带天线数据产生高忠诚度，高动态范围图像，同时在计算上有效且可靠地对未建模无线电发射的吸收进行了鲁棒性。我们将这种校准和成像策略应用于150 MHz的启动和LH字段的深度图像，总计$ \ sim80 $和$ \ sim100 $小时的集成，并在这些低频$ \ simesim30 $和$ \ $ \ $ \ $ $ $ $ $ $ $ $ $ $ $ jy in in Inn in in Inn in in Inn in in Inn in Inn in Inn in Inn in Inn Inn in Inn y sim $ jy $ jy $ y y in Inn in Inn in Inter的。该方法还用于减少第二个数据发布的整个范围数据。
The Low Frequency Array (LOFAR) is an ideal instrument to conduct deep extragalactic surveys. It has a large field of view and is sensitive to large scale and compact emission. It is, however, very challenging to synthesize thermal noise limited maps at full resolution, mainly because of the complexity of the low-frequency sky and the direction dependent effects (phased array beams and ionosphere). In this first paper of a series we present a new calibration and imaging pipeline that aims at producing high fidelity, high dynamic range images with LOFAR High Band Antenna data, while being computationally efficient and robust against the absorption of unmodeled radio emission. We apply this calibration and imaging strategy to synthesize deep images of the Bootes and LH fields at 150 MHz, totaling $\sim80$ and $\sim100$ hours of integration respectively and reaching unprecedented noise levels at these low frequencies of $\lesssim30$ and $\lesssim23$ $μ$Jy/beam in the inner $\sim3$ deg$^2$. This approach is also being used to reduce the LoTSS-wide data for the second data release.
