论文标题
表征Apertif主梁响应
Characterising the Apertif primary beam response
论文作者
论文摘要
语境。分阶段阵列进料（PAFS）是望远镜焦平面中的多元元素接收器，可以通过结合各个天线元件的复杂增益来同时在天空上同时形成多个光束。最近，Westerbork合成射电望远镜（WSRT）用PAF接收器升级，并进行了几个观察程序，包括两项成像调查和一次时间域调查。 APERTIF成像调查使用配置，其中40个部分重叠的化合物梁（CBS）同时在天空上形成，并以大约矩形的形状排列。目标。该手稿旨在表征40个Apertif CB的响应，以创建频率分辨的I，XX和YY极化经验梁形状。测得的CB映射可用于图像反卷积，主梁校正和APERTIF成像数据的镶嵌。方法。我们使用漂移扫描测量值来测量40 cb的Apertif的响应。我们在与Apertif成像调查相同的带宽上，在I，XX和18频率箱中的所有单个光束的光束图中得出了所有单个光束图。我们采样了梁的主叶，侧面裂片距离梁中心的半径为0.6度。此外，我们还为每个WSRT菜肴得出了光束地图。结果。我们介绍了梁形状和大小的频率和时间依赖性。我们使用高斯过程回归比较Apertif Continuum图像与NRAO VLA SKY SUMPLE（NVSS）目录之间的比较，将其与漂移扫描方法与漂移扫描方法相比的复合光束形状与具有独立方法得出的光束形状进行了比较。我们发现与两种独立方法得出的光束形状之间有很好的一致性。
Context. Phased Array Feeds (PAFs) are multi element receivers in the focal plane of a telescope that make it possible to form simultaneously multiple beams on the sky by combining the complex gains of the individual antenna elements. Recently the Westerbork Synthesis Radio Telescope (WSRT) was upgraded with PAF receivers and carried out several observing programs including two imaging surveys and a time domain survey. The Apertif imaging surveys use a configuration, where 40 partially overlapping compound beams (CBs) are simultaneously formed on the sky and arranged in an approximately rectangular shape. Aims. This manuscript aims to characterise the response of the 40 Apertif CBs to create frequency-resolved, I, XX and YY polarization empirical beam shapes. The measured CB maps can be used for image deconvolution, primary beam correction and mosaicing of Apertif imaging data. Methods. We use drift scan measurements to measure the response of each of the 40 CBs of Apertif. We derive beam maps for all individual beams in I, XX and YY polarisation in 10 or 18 frequency bins over the same bandwidth as the Apertif imaging surveys. We sample the main lobe of the beams and the side lobes up to a radius of 0.6 degrees from the beam centres. In addition, we derive beam maps for each individual WSRT dish as well. Results. We present the frequency and time dependence of the beam shapes and sizes. We compare the compound beam shapes derived with the drift scan method to beam shapes derived with an independent method using a Gaussian Process Regression comparison between the Apertif continuum images and the NRAO VLA Sky Survey (NVSS) catalogue. We find a good agreement between the beam shapes derived with the two independent methods.
