“Astrophysics from Antarctica”, was the title of a public talk given by Senior Lecturer in the School of Mathematics, Statistics and Computer Science, Dr Cynthia Chiang.
Chiang’s research focuses on exploring the history of the universe through fluctuations in the cosmic microwave background (CMB), the “afterglow” of the Big Bang. She specialises in building millimetre-wavelength telescopes and analysing data, and her past research projects include a wide variety of ground, balloon and satellite-based telescopes.
Cosmology is an exciting area of research which addresses some of humanity’s oldest questions which include: How did the universe begin? What is it made of? and What is its ultimate fate? To answer some of these questions, Chiang has travelled to some of the most remote corners of the earth in order to work on telescopes that have access to the clearest skies for CMB observations.
One such expedition included an entire impressive winter spent at the South Pole Telescope (SPT), a period in which the station is completely isolated and in total darkness. Chiang described some of the microwave telescopes that she helped to build and operate from Antarctica, which is one of the best observing sites in the world. She further discussed some of the challenges and rare aspects of daily Antarctic life.
Chiang has worked on several telescopes that aim to measure the temperature and polarisation fluctuations in the CMB with improved sensitivity, allowing researchers to tightly constrain the physics of the early universe. One of Chiang’s current goals is to test the theory of inflation, a period directly after the Big Bang during which the size of the universe is theorized to have increased one-hundred trillion, trillion times in roughly a billionth of a trillionth of a trillionth of a second.
One prediction of inflation is the existence of a gravitational wave background that imparts a unique imprint on the CMB by introducing a minuscule “curl” pattern in the polarisation. The detection of the curl pattern would provide powerful confirmation of the inflationary theory and would try to revolutionise our understanding of the universe.
Chiang is currently working on an experiment titled the SPIDER which is designed to measure CMB polarisation with the goal of detecting the curl signature from inflation.
SPIDER is a balloon-borne instrument that will launch from McMurdo Station in Antarctica at the end of 2013 and will circumnavigate the continent in a 20-30 day flight. The instrument consists of six independent telescopes bundled into a drum-shaped vessel that holds 1 000 litres of liquid helium for cooling the cameras. The multiple telescopes not only achieve high sensitivity, but they also provide redundancy for internal consistency checks.
Said Chiang: ‘UKZN has a strong presence in CMB data analysis. I hope that by teaming up with the CMB researchers at UKZN, I can provide opportunities for students to not only learn how to build instruments but to also use that hardware knowledge to become more effective data analysts. In addition, I am eager to work with the UKZN researchers to join the engineering and commissioning efforts for the Square Kilometre Array (SKA) project that will see South Africa in the spotlight for future years.’
The Director of the Astrophysics and Cosmology Research Unit, Professor Sunil Maharaj, said: ‘Dr Chiang’s presentation was excellent. She gave a unique insight into the science experiments taking place in Antarctica and the pictures of the landscape were stunning. She provided detailed explanation of problems experienced by scientists in this unique environment.’
The public talk was followed by an extraordinary night sky viewing.