New Science Data Challenge hones hunt for hydrogen

BY SKAO

Astronomers from around the world will start sifting for the hydrogen-21cm signal in an enormous mock dataset come October 2022.

The SKAO’s third Science Data Challenge (SDC3) reflects the SKA project’s initial driver – to read the history of the Universe as written in the language of hydrogen. The goal of the series of challenges is to prepare scientists for the actual SKA telescopes’ data to come in a few years.

The challenges are steadily growing in complexity and participation. While SDC1 attracted nine teams, SDC2’s count quadrupled to 40 teams and featured a dataset 300 times larger – far too colossal for any ordinary computer to handle.

The first two challenges tested participants’ methods to separate galaxies from noise. SDC3 will centre on simulated observations from the future SKA-Low telescope.

“Participating teams will be expected to extract the hydrogen- 21cm signal from our dataset,” SKAO postdoctoral fellow Dr Simon Purser explained. “This is no mean feat. Not only is the signal extremely faint, but it is heavily obscured by both galactic and extragalactic sources of emission.”

Due to the complexity of these observations, the SKAO has split the challenge into two independent parts: Foregrounds (SDC3a) running until March 2023, and Inference (SDC3b), which will start shortly afterwards.

As part of the first phase, teams will need to accurately subtract sources of foreground contamination from the simulated hydrogen-21cm signal. The inference challenge will then focus on extracting key information about the early universe from the signal. This includes studying the first stars, galaxies and black holes.

Once more, several international high-performance computing facilities around the world have generously donated processing time to participants. For this reason, teams will need to submit a brief proposal that outlines the approach they plan to take when registering. This will help the SKAO to effectively allocate supercomputer time.

You can find the registration link and more information on the SDC3 website: https://sdc3.skao.int/overview

A frequency snapshot from the dataset that will be used in the SKAO’s third Science Data Challenge. Areas of hydrogen absorption and emission are shown in dark and light, respectively.

SKAO