Spectral Line Analysis with the MWA
A series of new spectral line surveys will explore regions of our Galaxy in high resolution to further understand the noise properties of the Murchison Widefield Array (MWA), use low-frequencies to improve our understanding of chemical enrichment of the low-frequency sky, and assist in understanding the future SKA requirements for this type of science. Following on from the surveys completed and published during the PhD project of Chenoa Tremblay, we will continue to use the sophisticated pipeline developed on the Pawsey Supercomputer -- Galaxy to continue this work.
Area of science
Astronomy, Geosciences
Systems used
Magnus
Applications used
Python 2.7, WSClean, CASA, Miriad, MWA ToolsThe Challenge
The new generation of low frequency telescopes, in particular the MWA located in an extreme radio quiet zone, allows us the ability to probe the low-frequency chemical sky. The science goals of these low frequency detections range from understanding the formation mechanisms of sulfur and nitrogen bearing molecules to looking for amino acids and the building blocks of life. The goal of this project is to push the surveys to deeper levels by observing the regions of Orion, the Vela Supernova Remnant and the Galactic Centre to probe the cold gas to look for signs of molecules that are difficult to detect at higher frequencies (above 80 GHz). We also use this pipeline to look for HI absorption in the distant Universe to better set constraints on the Epoch of Reionisation.
The Solution
Currently, we have 600 observations with the MWA covering 30 hours on Vela, 6 hours on Orion Molecular cloud at multiple frequency bands, and upcoming observation in 2019 of 20 hours of the Galactic Centre. This is a data intensive project requiring approximately 1.2 million images of the sky to be made, calibrated, corrected for the ionosphere and made into searchable data cubes. As this type of search at low frequency is still investigating a new parameter space and may require further improvements to the pipeline for the MWA data analysis with the new long-baselines, this proposal represents only a fraction of the 5 million CPU hours estimated to complete this project in 2019. Currently, we have 600 observations with the MWA covering 30 hours on Vela, 6 hours on Orion Molecular cloud at multiple frequency bands, and upcoming observation in 2019 of 20 hours of the Galactic Centre. This is a data intensive project requiring approximately 1.2 million images of the sky to be made, calibrated, corrected for the ionosphere and made into searchable data cubes. As this type of search at low frequency is still investigating a new parameter space and may require further improvements to the pipeline for the MWA data analysis with the new long-baselines, this proposal represents only a fraction of the 5 million CPU hours estimated to complete this project in 2019.
The Outcome
Within 2019 we were able to calibrate and image almost 700 MWA observations to look for atomic transitions, molecules and study peculiar HII regions of active star formation towards the Vela Supernova Remnant and one known 5.1 red-shift galaxy. This required calibrating and creating over half a million images of the sky, which wouldn’t have been possible without the Pawsey systems.
List of Publications
The data took all of 2019 to process, but a number of publications are in process with this data:
“A SETI Survey of the Vela Region using the Murchison Widefield Array”, Tremblay, C., Tingay, S.
“MWA and ASKAP discovery of large AGN in the nearby elliptical galaxy NGC 2663” Velovic et al.
“Nitric Oxide Masers toward Evolved Stars” Tremblay, C. et al.
“Continuum Survey toward Vela and Puppis constellations with ASKAP and MWA.” Tremblay et al.
