Fourier Plane Image Combination by Feathering

TL;DR

This paper discusses the feathering technique for combining images in the Fourier domain to recover all spatial scales of astronomical objects, especially when using multiple instruments like interferometers and single dishes.

Contribution

It introduces and explains the feathering method for Fourier plane image combination, including implementation details and practical examples with radio observations.

Findings

Feathering effectively combines single dish and interferometric data.

The method recovers a wide range of spatial scales in astronomical imaging.

Examples demonstrate improved image fidelity across scales.

Abstract

Astronomical objects frequently exhibit structure over a wide range of scales whereas many telescopes, especially interferometer arrays, only sample a limited range of spatial scales. In order to properly image these objects, images from a set of instruments covering the range of scales may be needed. These images then must be combined in a manner to recover all spatial scales. This paper describes the feathering technique for image combination in the Fourier transform plane. Implementations in several packages are discussed and example combinations of single dish and interferometric observations of both simulated and celestial radio emission are given.