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GaLactic and Extragalactic All-sky Murchison Widefield Array survey eXtended (GLEAM-X) I: Survey Description and
N Hurley-Walker1, T J Galvin1,2, S W Duchesne1,2
1International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102, Australia.
Publications of the Astronomical Society of Australia : PASA
|May 2, 2022
Summary
We present a new low-frequency radio survey of the southern sky using the Murchison Widefield Array. This initial data release offers a wideband image and catalogue, paving the way for future discoveries.
Area of Science:
- Radio Astronomy
- Astrophysics
- Cosmology
Background:
- Low-frequency radio astronomy is crucial for understanding the early universe and cosmic evolution.
- Previous surveys have limitations in sensitivity, resolution, or frequency coverage.
- The Murchison Widefield Array (MWA) offers unique capabilities for widefield, low-frequency observations.
Purpose of the Study:
- To conduct a new low-frequency wideband radio survey of the southern sky.
- To release initial data products, including images and catalogues, from a pilot field.
- To establish a foundation for future data releases from the GLEAM-X survey.
Main Methods:
- Utilized the Murchison Widefield Array "extended" Phase II configuration for observations between 72-231 MHz.
- Processed data to generate continuum and polarisation images, multi-frequency catalogues, and transient search data.
- Performed source-finding on a wideband image (170-231 MHz) with a resolution of 2'-45".
Main Results:
- Published an initial data release covering 1,447 deg² for a pilot field.
- Produced a wideband source-finding image with a root-mean-square noise of 1.27 ± 0.15 mJy beam⁻¹.
- Generated a catalogue of 79,124 components, with 71,320 spectrally fitted, demonstrating high completeness and reliability.
Conclusions:
- This work represents the first data release from the GLEAM-X survey.
- The released data products (catalogue and images) are publicly available for scientific use.
- The survey is poised to deliver significant advancements in low-frequency radio astronomy.
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