CSIRO Outreach Report

Murchison Radio-astronomy Observatory (MRO) News

A signal detected from the first stars in the Universe was the subject of a paper published in Nature on 1 March 2018. The discovery was made by a team of US astronomers using a small spectrometer, located in Australia at CSIRO’s Murchison Radio-astronomy Observatory (MRO).

Dr Judd Bowman and his team from Arizona State University, have been working on the Experiment to Detect the Global EoR (Epoch of Reionization) Signature (EDGES ), for 12 years. Nine years ago he started doing the observations from the MRO, after searching for the best place to locate the instrument.

This detection highlights the exceptional radio quietness of the MRO, particularly as the feature found by EDGES overlaps the frequency range used by FM radio stations. Australian national legislation limits the use of radio transmitters within 161.5 miles (260 km) of the site, substantially reducing interference which could otherwise drown out sensitive astronomy observations.

The MRO was developed by CSIRO for its Australian Square Kilometre Array Pathfinder (ASKAP) telescope and also hosts the low-frequency telescope, the Murchison Widefield Array (MWA), developed by an international collaboration, led by Curtin University. These telescopes make use of the radio-quiet nature of the site and also are important precursors to the Square Kilometre Array itself.

The MRO is the Australian site for the low-frequency telescope of the future Square Kilometre Array, SKA1 Low.

Here is an explanatory video on the ‘first stars’ discovery.

Figure 1: Artist’s rendering of how the first stars in the universe may have looked

Figure 2: EDGES ground-based radio spectrometer, CSIRO’s Murchison Radio-astronomy Observatory in Western Australia. The instrument on its wire mesh ground plane. The bottom panel shows a closer view of the antenna before the extension of the ground plane. The two elevated metal panels form the dipole-based antenna and are supported by fiberglass legs. The balun consists of the two vertical brass tubes in the middle of the antenna. The receiver is located under the white metal support structure.

Report provided by Annabelle Young, CSIRO