A powerful telescope affording a view of the universe
unmatched by most ground-based observatories gazed onto distant galaxies for
the first time from deep in Chile's Atacama desert.
The Atacama Large Millimetre/submillimetere Array (ALMA), a
joint project between Canada, Chile, the European Union, Japan, Taiwan and the
United States, officially opened for astronomers after a decade of planning and
construction.
The world's biggest astronomy project, ALMA is described as
the most powerful millimetre/submillimetre-wavelength telescope ever and the
most complex ground-based observatory.
The first images arrived at the mega-site in northern Chile
from 12 of the 66 radio telescopes.
"Today marks the recognition of the successful
coalition of thousands of people from all over the world all working with the
same goal: to build the world's most advanced radio telescope to see into the
universe's coldest, darkest places, where galaxies and stars and perhaps the
building blocks of life are created," said ALMA director Thijs de Graauw.
ALMA differs from visible-light and infrared telescopes by
using an array of linked antennas acting as a single giant telescope, and
detects much longer wavelengths than those of visible light, rendering images
unlike most others of the cosmos.
Although similar instruments are used in other locations,
ALMA's are 10 to 100 times more powerful than others currently in operation,
said ALMA scientist Lars Nyman.
ALMA's location also provides a unique advantage, because of
the extreme aridity of the Atacama and its altitude of 5,000 metres above sea
level.
It is in the same region as the European Extremely Large
Telescope, due to begin operation in 2018.
First images
The first images were of the Antennae Galaxies, a pair of
colliding galaxies with dramatically distorted shapes some 70 million light
years away in the Corvus constellation.
ALMA's view "reveals something that cannot be seen in
visible light: the clouds of dense cold gas from which new stars form,"
according to ALMA.
"This is the best submillimetre-wavelength image ever
made of the Antennae Galaxies."
Images like "will be vital in helping us understand how
galaxy collisions can trigger the birth of new stars," said ALMA.
Project scientist Richard Hills said the results were
"better than expected".
"They're really beautifully clear, there's nothing that
messes up the data... it really shows us what is going on inside their galaxies
we had been looking for," the former Cambridge University scientist added.
"We've been waiting a very long time to get to the
point where ALMA is really able to do science. Some people have been working on
this project for more than 20 years. So, it has been a long road, but all the
bits and pieces that we need to make this telescope work, now come
together."
One of the projects chosen for ALMA observations was that of
David Wilner of the Harvard-Smithsonian Centre for Astrophysics in Cambridge,
Massachusetts.
"My team hunts for the building blocks of solar
systems, and ALMA is uniquely equipped to spot them," Mr Wilner said.
His target is AU Microscopii, a star 33 light years away
that is only 1 per cent of the age of the sun.
"We will use ALMA to image the 'birth ring' of
planetesimals that we believe orbits this young star," he said.
"We hope to discover clumps in these dusty asteroid
belts, which can be the markers of unseen planets."
Masami Ouchi of the University of Tokyo will use ALMA to
observe Himiko, a very distant galaxy churning out at least 100 suns' worth of
stars every year and surrounded by a giant, bright nebula.
"Other telescopes cannot show us why Himiko is so
bright and how it has developed such a huge, hot nebula when the ancient
universe all around it is so calm and dark.
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