(GIST OF SCIENCE REPORTER) Square Kilometer Array

[November-2021]

Square Kilometer Array

Introduction:

Square Kilometer Array (SKA) Observatory) is a global project radio telescope, for addressing a wide variety of cutting-edge science goals, ranging from the birth of the Universe to the origins of life. At present, 12 nations, including India, are participating in this mega-science project, and some more are expected to join shortly. The SKA is expected to revolutionise radio astronomy, while driving the growth of many important new state-of-the-art technologies.

Background:

Though the first ideas to build a large radio astronomy facility like the SKA were put forward in the early 1990s, the formal project work started around 2012 with the setting up of the SKA Organisation in November 2011. Given the size and complexity of the full SKA, a decision was taken that the SKA should be built in two phases. The first, SKA1, would comprise ~10% of the final collecting area of the telescopes, but would still be significantly better than any existing facility; and the second phase, SKA2, comprising the remainder, would follow once the first phase was working.
After an extensive search for suitable sites to locate the SKA observatory, remote and radio-quiet areas were identified in Australia and South Africa, and it was agreed to locate the low-frequency component of the observatory (SKA1-Low) in Australia, and the higher-frequency component (SKA1-Mid) in South Africa.
Both Australia and South Africa have established precursor telescopes on the two sites, which has proved useful to test and prepare the sites for eventually locating the SKA there. Further, it was decided to have the operational headquarters of the SKA in the UK – at Jodrell Bank, near Manchester.
The detailed design of the SKA1 was carried out during 2014 to 2020 by a set of nine core design consortia authorised by the Board of the SKA Organisation. Each consortium reflected the international nature of the SKA partnership with institutes from around the world contributing to the design effort. After a bridging phase where useful prototyping activities have being carried out since 2020, the SKA project now is set to transition into full-fledged construction phase by the end of 2021.
A new governance vehicle – an Inter-Governmental Treaty Organisation, called the “SKA Observatory (SKAO)” – that came into being from March 2021, has replaced the SKA Organisation and will oversee the construction of SKA1 and the subsequent operations and possible further expansions of the project over the next few decades.

Science Potential of SKA:

Since the initial definition of the SKA, the science case for the SKA has developed and evolved significantly in several steps, with the two volume compendium Advancing Astrophysics with the Square Kilometre Array (SKA Science Team, 2015) providing the latest and most comprehensive coverage of the vast range of science that the SKA will be capable of. Some of the main science goals for the SKA are as follows:
1. Detect the first stars and galaxies that formed in the early Universe.
2. Trace the evolution of galaxies from their earliest formation to the current stage.
3. Study the large scale structure of the Universe, probing dark matter and dark energy.
4. Understand the distribution and structure of magnetic fields in the Universe and their influence on its evolution.
5. Test existing theories of gravitation in extreme environments such as close to black holes, using pulsars as probes.
6. Detect low frequency gravitational waves, which are complementary to gravitational waves detected by LIGO type observatories.
7. Study the formation of planets around nearby stars, detect complex molecules that are precursors to life, and scan for signals from extra-terrestrial intelligence.
8. Last, but not the least, make serendipitous discoveries! This always happens whenever a new telescope much more powerful than any existing facility comes into operation.

Way ahead:

India’s participation in the Square Kilometer Array (SKA) mega-project is an excellent opportunity for India to showcase its S&T capabilities on the global stage, while reaching the benefits from the development of next generation technologies, and guaranteeing Indian astronomers the right of access to the best experimental radio astronomy facility of the future.