Square Kilometre Array (SKA): Extra-terrestrial Questions Require Extraordinary Machines

What did the Universe look like when the first galaxies formed? What exactly is ‘dark energy’? Is it really driving apart the cosmos at an accelerating rate? Is there other life out there? All questions which have perplexed the public and scholars alike through the ages, and which could stand to finally be answered.

The unprecedented sensitivity of the SKA’s thousands of individual radio receivers combine to create the world’s largest radio telescope, a unique configuration giving it unrivalled scope in observations.

For astronomers, this means insight into the formation and evolution of the first stars and galaxies after the Big Bang, the role of cosmic magnetism, the nature of gravity and possibly even life beyond Earth.

“The scale of the SKA represents a huge leap forward in both engineering and research and development towards building and delivering a unique instrument,” the organisation states, “born of the ambition to explore the cosmic dawn and designed to study extreme events and reveal the hidden fabric of space.”

NEW ERA, NEW BRAND

Signalling a new chapter in the SKA Project’s history, the newly born SKA Observatory (SKAO) brand was unveiled following approval by the SKAO Council in April this year. The SKAO now joins a select group of intergovernmental organisations dedicated to fundamental research, and is only the second such organisation to be dedicated to astronomy.

“The SKA Observatory will transform our understanding of the universe by building and operating cutting-edge radio telescopes, benefitting society through collaboration and innovation,” it summates.

Following several years of intricate and groundbreaking design work, the newly created Observatory will oversee the construction and operation of two telescopes over the next decade. These will be the two most advanced radio telescope networks on Earth and promise to answer fundamental questions about the Universe.

“SKA has reached a significant point in its journey that has already seen some incredible milestones,” states SKAO Director-General Prof. Philip Diamond, of the project that has been more than 30 years in the formulation to reach this juncture. Two decades on from the development of the original SKA brand, the project has grown monumentally in scope and ambition and gone through major changes.

“We wanted this process to be as inclusive as possible from the start, to reflect collectively on the fundamentals of our new observatory,” explains William Garnier, the SKAO’s Director of Communications of this five-year collaborative process.

“I am extremely pleased with where we landed, and feel this brand we are launching today truly reflects who we are and who we are meant to become as a global observatory.”

THE RIGHT DIRECTION

“The SKA Observatory has an unprecedented opportunity to position itself as the global research infrastructure with the broadest overall impact of any currently in planning or implementation,” the organisation continues, and the appointment of its telescope directors in both Australia and South Africa sees two widely respected figures in the field become the most senior SKAO operations representatives in the telescope host countries.

“This is a unique and exciting opportunity to establish the SKA Observatory team in Australia and help deliver the world’s next generation radio telescopes,” enthused Dr Sarah Pearce, currently Acting Chief Scientist of Australia’s national science agency CSIRO and set to head up the SKAO’s low-frequency telescope in Australia.    

“I’m honoured to continue my work on the SKA Project in this new role, and I look forward to building a long-lasting partnership between the SKA Observatory and CSIRO.”

Dr Lindsay Magnus, meanwhile, is currently Head of Operations at the South African Radio Astronomy Observatory (SARAO), and now will be the director of the SKAO’s mid-frequency telescope in South Africa. “As a South African,” Magnus said, “I am proud to have been chosen to play a key role in the realisation of this iconic international scientific instrument. I am humbled to undertake this task to transform as many lives as possible in South Africa as well as the rest of the world.”

The pair, bringing a wealth of experience and technical prowess including in managing and operating SKA precursor facilities, will establish and lead the SKAO’s operations in their respective countries as the telescope systems are distributed across several locations.

“I am delighted to welcome Dr Pearce and Dr Magnus as our SKAO telescope directors, both of whom are highly regarded professionals in our field,” says SKAO Director-General Prof. Phil Diamond.

“Their expertise on the SKA Project, deep knowledge of the telescope sites and related infrastructure, and of course their established relationships with our partner organisations in each country means they will be able to hit the ground running as we begin the Construction Phase this year.”

CONSTRUCTION IS COMING

Having sailed through its System Critical Design Review in December 2019, a series of independent external panels have now examined the detailed design, costing, future operations plan and business support functions of the SKA, approving its overall readiness to move from planning to construction.

On the operations side, one major independent review looked at the plan to operate and maintain the telescopes to ensure the collection, processing and delivery of data to the international science community. The second assessed the business-enabling functions needed to support the future SKA Observatory in delivering on its mission.

“Both operations reviews have shown that SKAO is as well prepared as you can be at this stage of the project for the future operation of the Observatory,” outlined Dr Andreas Kaufer, Director of Operations for the European Southern Observatory (ESO).

“The responses of the team to the review boards’ questions demonstrated a deep understanding of the issues and challenges ahead.”

Successfully navigating these reviews and audits gives extra confidence to decision-makers to approve funding for construction later this year, and to the SKA teams across the partnership, as well as the science community at large, that the project is ready to be propelled into the stratosphere.

“I’m proud our teams were able to conduct these major reviews with such a positive outcome in the middle of a pandemic,” said Dr Lewis Ball, SKA Director of Operations. “It’s been a very intense period of a few months, but we couldn’t have delivered these results without the years of work behind it by people at the SKA Organisation.”

Dr Joseph McMullin, SKA Programme Director, concluded: “We’ve done all the planning, now it’s time to deliver.”

GALACTIC DISCOVERY

Operated by the SARAO, MeerKAT is the world’s biggest radio telescope and one of two SKA precursor instruments in South Africa. On multiple occasions already it has demonstrated its scientific prowess, but eclipsing all is the discovery of a cluster of 20 galaxies by the MeerKAT International Gigahertz Tiered Extragalactic Exploration (MIGHTEE) survey, one of the largest projects in progress.

Its maiden identification is testament to the exceptional sensitivity MeerKAT provides astronomers. “This galaxy group sits in an area of sky that has been studied with many other telescopes, but only with MeerKAT is the group structure revealed so clearly,” elaborated Dr Natasha Maddox, research scientist at Ludwig Maximilians Universität in Munich, and co-chair of the MIGHTEE neutral hydrogen working group.

“Galaxy environment strongly affects how galaxies change and grow, and observations of neutral hydrogen with MeerKAT give us a new observational window into structures like this.”

Most star-forming galaxies are embedded within a cloud of cold neutral hydrogen gas, which is extremely faint and can only be detected in radio wavelengths. By observing it, astronomers are able to glean answers to centuries-old fundamental questions over the evolutionary processes that take place in galaxies.

“This discovery shows that our MeerKAT observations caught a galaxy group in the early stages of its assembly, which is very uncommon,” concluded Dr Anastasia Ponomareva, researcher at the University of Oxford. “Therefore, this discovery is not only important per se, but will set new grounds for understanding of how galaxies are assembled into groups and transformed by their environment.

“We expect many wonderful findings like this in the future, thanks to the ongoing MeerKAT surveys.”