Alexander Andersson is working on the instrument for what will be the world’s largest optical telescope. Find out about his ground-breaking work at STFC’s UK Astronomy Technology Centre in Edinburgh…
Alex is in his 3rd year of an integrated Masters in Physics at the University of Manchester. He came to STFC’s UK Astronomy Technology Centre (UK ATC) to work with Instrument Scientist, Dr Oscar Gonzalez, on what will be the ‘biggest eye on the sky’ – the Extremely Large Telescope, currently under construction in Chile.
UK ATC has a leading role within the consortium that is designing and building HARMONI, one of the first-light instruments on the ELT.
Here Alex shares with us how he’s helping to develop one of the key science cases of this world class instrument for the world’s largest optical telescope.
Alex, tell us a little bit about the project?
“I’ve been tasked with evaluating how the team expect HARMONI to perform in a particular science case – looking at resolving stellar populations in the large elliptical galaxy, Centaurus A, which can be found in the constellation Centaurus in the southern hemisphere’s sky.
“With the current tech, we can only resolve individual stars in local galaxies and dwarf galaxies. Once HARMONI is running on the ELT we will be able to see at a high level of detail much, much further – about 12-13 million light years away. Looking at Centaurus A is of particular interest as there are no nearer galaxies of its kind for us to study.
“My work will help the HARMONI team to maximise observations from the ELT, which is very exciting.”
That sounds like a great challenge, can you share with us what you are doing?
“Essentially I will create a simulated star field – so that we can test what HARMONI will enable the ELT to see, compared to what is actually there.
“To do this I will work with data cubes – these are a bit like creating a graph, where you would plot values – but in 3D! Data cubes let us capture lots of different information about a celestial object, for example its position in the sky, its wavelength, speed that it’s moving etc. I will then feed those values into a simulation model – we use the HSIM program (which is a simulation program developed for HARMONI).
“The data that comes out of the simulation model can then help us to optimise the performance of the instrument and calibrate its settings, depending on things like: the atmospheric condition (‘seeing‘); the instrument’s correction for the atmospheric turbulence; how long the observing run is; what wavelength range to use etc. to ensure that what comes out of the telescope is able to give as much insight into our Universe as possible.”
What have you learned so far, in your time here at UK ATC?
“From the simulations I've run so far, the ELT is going to be truly revolutionary. In one night of observations, using standard atmospheric conditions and laser tomography adaptive optics, it could be possible to resolve the spectra of hundreds of individual stars in Centaurus A in a single pointing. This is a significant improvement on the current suite of instrument capabilities, which today, can only perform this type of studies in our own galaxy or local dwarf galaxies.”
Has this been a valuable experience for you?
“This is not stuff that we get taught at undergraduate level and so I am really excited to be learning and gaining an understanding of how an instrument like HARMONI works; how the world’s most advanced telescope on land – the ELT – will work; and how all the systems integrate to enable astronomers to see in more detail than has ever been possible to see before. And to have had a role in addressing some of the challenges of resolving stellar populations at these mind-blowing distances is just great.”
What’s next for you?
“This is a good opportunity for me to test whether I actually enjoy astronomy research. Next year I will finish my Masters portion of my degree – which, since I’m based very close to Jodrell Bank, the head office for the Square Kilometre Array (SKA), the world’s largest radio telescope, my Masters project will most likely focus on radio astronomy. Then, seeing as I’m loving my time here, I’m definitely considering a PhD in some form of astronomy!
“I’m also open, at the moment too, to perhaps a career in software engineering as well as educational science outreach and teaching. There are lots of options to consider, and I’m excited to explore what I like best.”
Last updated: 12 September 2019