Application of a Bayesian Method to Absorption Spectral-Line Finding in Simulated ASKAP Data

2011/09/30 by J. R. Allison, E. M. Sadler, M. T. Whiting · 4 citations
Physics and Astronomy · #Electrical and Electromagnetic Research #Galaxies: Formation, Evolution, Phenomena #Radio Astronomy Observations and Technology #astro-ph.CO

paper · pdf · doi:10.1071/as11040

8 pages, 5 figures and 1 table; accepted for publication in PASA

arxiv created 2011/10/12 · openalex publication_date 2011/10/26 · arxiv updated 2015/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04

Abstract

Abstract The large spectral bandwidth and wide field of view of the Australian SKA Pathfinder radio telescope will open up a completely new parameter space for large extragalactic HI surveys. Here we focus on identifying and parametrising HI absorption lines which occur in the line of sight towards strong radio continuum sources. We have developed a method for simultaneously finding and fitting HI absorption lines in radio data by using multi-nested sampling, a Bayesian Monte Carlo algorithm. The method is tested on a simulated ASKAP data cube, and is shown to be reliable at detecting absorption lines in low signal-to-noise data without the need to smooth or alter the data. Estimation of the local Bayesian evidence statistic provides a quantitative criterion for assigning significance to a detection and selecting between competing analytical line-profile models.

Citations

• The NRAO VLA Sky Survey
• Australian SKA Pathfinder: A High-Dynamic Range Wide-Field of View Survey Telescope

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