Comparison of potential ASKAP HI survey source finders

TL;DR

This paper compares five automated 3D source finders for ASKAP HI surveys, evaluating their effectiveness in detecting galaxies to ensure survey goals are met.

Contribution

It provides a systematic comparison of five different source finding algorithms on simulated data, highlighting their relative performance in completeness and reliability.

Findings

Gamma-finder and S+C finder showed highest completeness.

Duchamp and Wavelet methods demonstrated strong reliability.

Performance varies significantly between methods.

Abstract

The large size of the ASKAP HI surveys DINGO and WALLABY necessitates automated 3D source finding. A performance difference of a few percent corresponds to a significant number of galaxies being detected or undetected. As such, the performance of the automated source finding is of paramount importance to both of these surveys. We have analysed the performance of various source finders to determine which will allow us to meet our survey goals during the DINGO and WALLABY design studies. Here we present a comparison of the performance of five different methods of automated source finding. These source finders are Duchamp, the Gamma-finder, CNHI, a 2D-1D Wavelet Reconstruction and S+C finder, a sigma clipping method. Each source finder was applied on the same three-dimensional data cubes containing (a) point sources with a Gaussian velocity profile and (b) spatially extended model-galaxies with inclinations and rotation profiles. We focus on the completeness and reliability of each algorithm when comparing the performance of the different source finders.