SKA Science Data Challenge 3a

© SKA Observatory

When it becomes operational later this decade, the SKA Observatory will provide tremendous improvements in sensitivity and will generate enormously more data than previous telescopes. Addressing this data deluge will require new and innovative data processing and analysis methods — methods that are not only able to keep up with the enormous data volumes, but also to use them to drive revolutionary new scientific discoveries.

In order to prepare the astronomical community for this challenge, SKAO has been organizing a series of “science data challenges”. These provide science teams with realistic — but synthetic — datasets and challenge them to compete to derive the most convincing scientific results from them. To add some extra realism, the teams are supported by various data centres and computing facilities that are busy gearing up to provide the distributed SKA archive and data analysis system: the SKA Regional Centre Network.

After the Big Bang, our universe expanded and cooled to the point at which ionised hydrogen recombined to its atomic state, with the 21 cm hydrogen line subsequently being observed in absorption against the background. With the appearance of a significant population of galaxies, the first stars formed and began to heat their surroundings. This heating shifted the absorption profile of the 21 cm line into emission. However, as this heating continued, more of the surrounding gas became ionised to the point at which this emission ceased: the “epoch of reionization”, or EoR. To date, astronomers have only roughly constrained the time periods at which these important events occurred. However, a primary science goal of the SKA is understand that timeline in detail.

In Science Data Challenge 3a, which has recently completed, teams were charged with removing foreground emission originating from galactic and extragalactic sources in an EoR dataset. Twenty different teams, from all around the world, competed, with 12 different data facilities providing computing infrastructure — including the future Netherlands SKA Regional Centre, a collaboration between the ASTRON Science Data Centre and SURF, the Dutch national e-infrastructure provider.

The challenge was won by Team HIMALAYA, a Chinese team that was directly supported by the NLSRC. Beyond that, Dutch scientists participated in teams that — although they didn't win — dominated the upper reaches of the leaderboard.

It's really exciting to see technical and scientific innovation from around the world coming together to make scientific discoveries with the SKA possible. And now we're looking forward to SDC 3b later this year...

For more information on SKA Science Data Challenge 3, take a look at https://sdc3.skao.int