The European Space Agency (ESA) has now given the green light for the final phase of the ARRAKIHS project, a telescope scheduled to be launched into Earth orbit in 2030. Lund researchers Oscar Agertz and Santi Roca Fabrega hold leading roles within the international collaboration.
What will your contribution to the project be?
“We are leading the development of the supercomputer models and simulations that will help researchers interpret the images captured by the telescope. The aim of the project is to understand how galaxies form and to study dark matter in the Universe by measuring the faint outer regions of nearby galaxies, beyond our own galaxy, the Milky Way. The telescope will produce vast numbers of images that will need to be analysed using our computer models, enabling us to gain a better understanding of how galaxies evolve,” says Oscar Agertz.
Why are the faint outer regions of galaxies so interesting?
“The faint light found at the edges of galaxies can provide us with important information about when and how those galaxies were formed. These regions act as a kind of archive of events from the distant past. This field of research is known as galactic archaeology. As galaxies form, they often collide with other galaxies. These dramatic events scatter stars far beyond the galaxies’ centres, creating a halo. By studying these ancient and faint remnants, we can learn how galaxies are assembled and uncover clues about dark matter, since it originated at an early stage in the history of the Universe,” says Santi Roca Fabrega.
How much dark matter could there be in space?
“Most of the Universe consists of things that we cannot see and do not yet fully understand. Dark matter is estimated to account for 23 per cent of the Universe, while dark energy makes up 72 per cent. Visible matter therefore represents only 5 per cent of the cosmos. Interestingly, one of the first people to identify evidence for dark matter was a Lund astronomer, Knut Lundmark. A pioneer in galaxy research, he measured the light from galaxies and, in 1930, published a study suggesting that dark matter must exist in space,” says Oscar Agertz.
Who is involved in the new research project?
“The project’s core team consists of researchers and staff from Spain, Switzerland, Austria, Belgium, Norway, Portugal and Sweden, with Spain serving as the lead nation. More than 250 scientists and engineers are currently involved, with additional participants from the United Kingdom, France, Denmark, the Netherlands, the United States, Taiwan, Thailand, Mexico and South Korea. They will contribute to the analysis of the images delivered by the telescope. The ARRAKIHS telescope is expected to operate for up to five years,” says Oscar Agertz.
ARRAKIHS sounds like the planet in the Dune films.
Is there a connection?
“Yes, I was actually the one who proposed the name to ESA. It is an acronym for the project’s full title: Analysis of Resolved Remnants of Accreted Galaxies as a Key Instrument for Halo Surveys. And yes, it is, of course, inspired by Frank Herbert’s Dune novels,” says Santi Roca Fabrega.
Oscar Agertz’s profile in Lund University’s Research Portal.
Santi Roca Fabrega’s profile in Lund University’s Research Portal.