A new approach for short-spacing correction of radio interferometric data sets

摘要

The short-spacing problem describes the inherent inability ofradio-interferometric arrays to measure the integrated flux and structure ofdiffuse emission associated with extended sources. New interferometric arrays,such as SKA, require solutions to efficiently combine interferometer andsingle-dish data. We present a new and open source approach for merging single-dish and cleanedinterferometric data sets requiring a minimum of data manipulation whileoffering a rigid flux determination and full high angular resolution. Ourapproach combines single-dish and cleaned interferometric data in the imagedomain. This approach is tested for both Galactic and extragalactic HI datasets. Furthermore, a quantitative comparison of our results to commonly usedmethods is provided. Additionally, for the interferometric data sets of NGC4214and NGC5055, we study the impact of different imaging parameters as well astheir influence on the combination for NGC4214. The approach does not require the raw data (visibilities) or any additionalspecial information such as antenna patterns. This is advantageous especiallyin the light of upcoming radio surveys with heterogeneous antenna designs.