Ground breaking European missions to probe early universe

The ESA has announced their next two L-class missions; one to study galaxy and black hole formation, and one to establish a gravitational wave observatory.

The so called Large, or L-class, missions will be named L2 and L3 respectively. L2 will consist of an X-ray observatory to investigate ‘the hot and energetic universe’, while L3 will probe the ‘gravitational universe’.

L2, due for launch in 2028, will attempt to answer two key questions; How and why ordinary matter forms the galaxies and galactic clusters we see today, and how black holes grow and influence their surroundings?

Professor Andy Fabian from the Institute of Astronomy at the University of Cambridge hopes to lead the delivery of the major space observatory, which will enable astronomers to measure the properties of galaxy clusters in the distant Universe and map their physical characteristics to understand how they first assembled when the Universe was two billion years old.

It is hoped they will also observe the first supermassive black holes and formation of galaxies less than a billion years after the Big Bang. This will involve studying X-ray emissions – the most reliable and complete way of revealing the secrets of black holes.

“Processes originating close to black holes are able to influence galaxies and galaxy clusters on scales up to a billion times larger – this ‘cosmic feedback’ is therefore an essential ingredient of galaxy evolution models,” Fabian said.

[caption id="attachment_36590" align="alignright" width="200"] Artist’s impression of one of the eLISA payloads in orbit credit: AEI/MM/exozet[/caption]

In 2034, the ESA plans to launch L3, or eLISA (the evolved Laser Interferometry Space Antenna), a follow-up to LISA Pathfinder due to launch next year. This mission will involve establishing a gravitational wave observatory which researchers at Imperial College London say will expand the observable Universe by opening up a ‘sound channel’ where there was previously only light.

Gravitational waves were predicted by Einstein, but have never been witnessed directly as they do not give off light or an electromagnetic spectrum. They are thought to originate from violent cosmic events so researchers will listen to waves made by early black holes, thousands of hidden pairs of stars, and even the Big Bang.

“This mission will enable us to study the Universe in a completely new way – we’ll be ‘listening’ to it as well as looking at it,” said Professor Tim Sumner, who leads the eLISA work at Imperial.  “We’ll have a totally different way of collecting information. It’s as though we’ve been watching a television with the sound off, and now we’re going to be able to turn the sound up and have a much clearer sense of what’s happening.

“The possibilities are mind-blowing. We’ll be able to get to grips with black holes; see how gravity works more precisely than ever before; and potentially even see what happened in the seconds after the Big Bang.”

By seeing how waves from early black holes are stretched out as they move toward us through an expanding Universe, eLISA might also shed light on the mystery of dark energy.

“This is a once in a lifetime opportunity to be at the heart of a mission that will yield completely new insights into the nature and origin of our Universe,” said Dr Harry Ward, who leads the University of Glasgow LPF and eLISA work.

“We have opened up a new scientific roadmap for Europe that will establish our leadership in this field for the next two decades while we develop and implement new technologies for these exciting missions,” said Professor Alvaro Gimenez, Director of Science and Robotic Exploration at the ESA.