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Breathing in the Stars – 2018 Harley Wood Lecture

In conjunction with the Annual Scientific Meeting, the Astronomical Society of Australia sponsors a public lecture in the city where the Scientific Meeting is held. The lecture is named in memory of Dr Harley Wood, the first President of the ASA. In 2018, the Meeting was held at Swinburne University of Technology, in Hawthorne, Melbourne and our Centre Director, Professor Lisa Kewley was invited to give the public lecture.

Lisa gave an entertaining and informative talk of the history of oxygen atoms in the Universe – how they were created, their journey through time and space, and how they got to be on Earth with us breathing oxygen molecules. 

The audience was largely interested members of the public, with a large percentage of children and teenagers, eagerly awaiting new astronomy knowledge. Lisa was able to explain concepts in a way non-astronomers could readily understand, whilst introducing some of the observational and theoretical cosmology that ASTRO 3D is working on:

Model of the formation of the first stars, with hydrogen and helium clumping together with gravity causing the first stars to form.

ASTRO 3D not only observes stars and galaxies using light, x-ray, infrared and radio waves through telescopes, we also use Australia’s best supercomputers to input that data and model what we think the evolutionary processes in the Universe were:

Modelling of the Epoch of Reionisation – where the red neutral hydrogen atoms have their electrons stripped and form hydrogen ions (charged particles) and the Universe became transparent and the white first stars formed

After the first stars formed, gravity then clumped together the stars to form the first galaxies:

Modelling of the evolution of the oldest stars clumping together to form the first galaxies

But how did the oxygen get out of the stars? Either from supernovae exploding or from solar winds:

 

Lisa then explained how ASTRO 3D is using new technologies to gather spectroscopic data from the stars and galaxies, so that for every pixel of light we gather from our telescopes, we are also able to understand the chemical makeup of stars and galaxies – this will help us understand star and galaxy evolution, with the help of supercomputers, in a way we’ve never been able to before.

Scientists love oxygen because it has a very distinct spectral signature

It is also a really exciting time in astronomy because we are using and developing the next generation of ground and space telescopes, which will allow astronomers to view even fainter, further away and older objects than ever before. Astronomers are increasingly using Gravitational Lensing as a way of seeing very old and distant galaxies.

 

And Lisa finished up with a video of the future James Webb Space Telescope (JWST) being developed by NASA in collaboration with a huge number of international partners. The JWST will be an infrared telescope, positioned further out in space than any other telescope, and will serve thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

There were some really interesting questions from the audience, who really appreciated learning more about this fascinating aspect of ASTRO 3D research from Prof. Lisa Kewley!