Australian researchers and engineers are helping design and deliver a new instrument for one of the world’s most productive telescopes.
The Blue Multi Unit Spectroscopic Explorer (BlueMUSE) is an integral-field spectrograph destined for the European Southern Observatory’s Very Large Telescope (VLT), which Australia has access to through a 10-year Strategic Partnership.
Alongside traditional 2D images, BlueMUSE splits the light from stars and galaxies into their component colours, helping better understand their nature.
“We’ll be able to define exactly where the star-forming regions, galactic nuclei, supernova remnants, and planetary nebula are … and better analyse their chemical composition and kinematics,” says Macquarie University’s Associate Professor Ángel Rafael López-Sánchez, who leads the Australian BlueMUSE Science team.
BlueMUSE builds on the VLT’s existing MUSE instrument, one of the world’s most powerful and high-impact astronomical tools.
It will observe in shorter and therefore bluer wavelengths than MUSE, with a higher spectral resolution. This will help astronomers answer key questions about stellar evolution, faint galaxies, intergalactic matter, and even Solar System objects.
“BlueMUSE will go much deeper and we’ll be able to resolve these kinds of features much better,” says A/Prof López-Sánchez.
The instrument’s wide field of view means astronomers can look at the space around galaxies to better understand the environment around them.
“You can look into a one arcminute field of view, which is like a card held (edge-on) at arm’s distance,” says Macquarie University senior lecturer Dr Tayyaba Zafar.
“You can focus not just on the galaxy you’re looking at, but all the nearby stuff around it. With 3D spectroscopy, you then see how the material, gas, or metals are interacting around it.”
Australia tapped to help build BlueMUSE
ESO signed an agreement for the construction of BlueMUSE last week. Australia will help build and deliver it to the VLT in Chile, with first light expected in 2034.
Funding for the local effort comes from Astronomy Australia Ltd. It will be led by Australian Astronomical Optics, one of three nodes of the country’s Astralis Instrumentation Consortium. Distinguished Professor Jon Lawrence is their Head of Optical Instrumentation.
“We’re responsible for the splitting optics, the precision optics that then feed all that light to the different spectrographs, along with the overall mechanical structure and enclosure, which provides a very precise thermal environment,” he says.
Australia was tapped to play this critical role thanks to decades of work in precision optics on ESO and local observatories, like the KOALA instrument on the Anglo-Australian Telescope, which can also observe blue light.
The agreement comes during a 10-year Strategic Partnership between Australia and ESO, which began in 2017. Modern observatories are so complex and expensive that few countries can go it alone. The $129 million partnership offers Australian astronomers observing time on some of the world’s best instruments, along with the chance for Astralis and industry to contribute next-generation technology.
About 30 full-time equivalent specialist jobs will flow to Australia from the project. Local suppliers in precision engineering and other industries are expected to play a role in development.
Despite the eight-year wait for BlueMUSE data, astronomers are excited about what the instrument will help them discover.
“I’m excited to see these weird blue compact dwarf galaxies that seem like giant nebula, but they’re actually dwarf galaxies with a lot of fireworks, a lot of emission lines, and a lot of chemical and kinematics processes,” says A/Prof López-Sánchez.
“Some other galaxies, too, we don’t know exactly what they are. But the power of BlueMUSE will help us disentangle that.”
