Chalmers will upgrade giant telescope Alma with new technology

Before its construction is even completed, the new telescope Alma is embarking on an upgrade – with state-of-the-art technology from Chalmers. The upgrade to the giant telescope in Chile will help astronomers to investigate the earliest galaxies, and to search for water in other planetary systems.

The oversight board for Alma has authorised the design and building of an additional set of receivers, which will enable the telescope to access a part of the spectrum of light that it cannot currently study. The receivers will be built by an international consortium in which Chalmers and Onsala Space Observatory play key roles.

Hans Olofsson, professor of radio astronomy at Chalmers and director of Onsala Space Observatory, is delighted by the new task. “We´re very pleased to be involved in making Alma one of the biggest and best observatories of our time. The contract is worth 50 million SEK for Chalmers over 5 years. During the period Alma is under construction a total of 180 million SEK will be returned to Sweden in the form of contracts”, he says.

Alma – the Atacama Large Millimeter/submillimeter Array – is the world’s largest astronomy project. This powerful new facility on the Chajnantor plateau in Chile is giving astronomers insight both into how the Universe and its galaxies have evolved since the Big Bang, and how stars and planetary systems formed in our own galaxy. Although only half of its final total of 66 antennas are currently in place at high altitude in northern Chile, Alma is already operating and making scientific observations with a partial array.

“Alma´s first discoveries have already given us a taste of what awaits us when the telescope is completed in 2013. But we won´t stop there. These new receivers will make it possible for us to take even better advantage of Alma´s fantastic site on Chajnantor”, says Wolfgang Wild, European project manager for Alma. The new receivers were originally designed, developed, and prototyped by Onsala Space Observatory´s Advanced Receiver Development group, based at Chalmers. Six of these receivers have already been built and supplied to Alma.

Over the next five years, all 66 of Alma´s antennas will be equipped with these new receivers. To do this, including spares, another 67 units need to be built.“Our role will be to, together with our colleagues in the Netherlands, manufacture 67 new receivers that are just as sensitive as the six that we have already built in our lab in Gothenburg”, says Victor Belitsky, professor of radio and space science at Chalmers, who will be technical lead for the consortium.

The receivers will be used to study some of the earliest galaxies in the Universe and will help us to understand when some of the first stars formed. They will also enhance astronomers´ abilities to measure the presence of water – a molecule essential to life – in the dusty disks where planets are believed to form, and in the atmospheres of planets and comets in our own Solar System.

Water in space can be tricky to measure accurately, because of the confusing effects of observing through the water vapour in Earth´s atmosphere. The way in which Alma´s “Band 5” receivers will measure water reduces some of these difficulties.The decision to fund this enhancement of Alma, even before the telescope is completed, was made by the Alma Board in April 2012. On 9 May 2012, the decision was approved by ESO´s Finance Committee. The upgrade is expected to be completed in 2016.