An expedition to Marion Island – by a team of scientists led by a Durban-based researcher – could help academics gain a better understanding of the universe’s development.
Dr Cynthia Chang, a senior lecturer at UKZN’s Astrophysics and Cosmology Research Unit, and astrophysics PhD students Liju Philip, Ridhima Nunhokee and Heiko Heilgendorff recently returned from a research trip to the island where they conducted work on the Probing Radio Intensity at high-Z from Marion (Prizm) telescope.
Prizm is a low-frequency radio telescope that collects information about the universe during the “cosmic dawn”.
The cosmic dawn is the period a few hundred million years after the big bang when the first stars in the universe formed.
The light from these first stars is too dim for optical telescopes to see, therefore they have never been measured directly.
The telescope is designed to make this measurement, and data received from it could help in determining when the first stars and galaxies formed.
The telescope works by observing the average brightness of the sky below 250 MHz.
“At these frequencies, it is impossible to get clear readings in populated areas due to interference from man-made radio signals.
“FM radio stations, for example, operate between 88 and 108 MHz, which is right where we expect the cosmic dawn signal to peak.”
In their quest to capture uncontaminated data, the astronomy team selected Marion Island as the location for the telescope.
This island, they explained, was separated from the nearest continental landmasses by 2 000km and was one of the most radio-silent locations in the world.
The island lies in the “Roaring Forties”, an area notorious for high winds and rain, which posed challenges for the team in setting up their equipment. Also, the team had only three weeks to get everything up and running.
However, the astronomy team succeeded in deploying two new antennae on the Prizm telescope, observing at 70 and 100 MHz.”
Chiang said Marion Island was “a fantastic new location” for radio astronomy, and they were “very excited” to see the data from the forthcoming year of observations.
The researchers said Marion Island was important as a new place for low frequency astronomy as it might provide the best place to observe ultra-low frequencies (10 MHz).