AMSTAR

Millimetre/sub millimetre astronomy, a relatively new branch of astronomy, has opened up a new window on the cold, dust obscured Universe. With sensitive bolometers and heterodyne techniques the millimeter astronomer may see through the dense and cold molecular clouds that populate interstellar space. These clouds are the birth places of stars and their observation holds great promise for understanding

• the formation of stars and their planetary systems in the Milky Way
• star formation in external galaxies, which controls their evolution
• Early Universe research - using the large European mm-wave telescopes, astronomers have shown that molecular lines and dust emission may be seen in regions of star formation with red-shifts as great as 4.7, so remote that they give us a glimpse of the Universe when it was but 10% of its present age.

Such is the promise of this field of research that ESA will launch in 2007 a satellite (Herschel) devoted to mm/submm observations, and ESO, in collaboration with the United States (NSF), will build the Atacama Large Millimetre Array (ALMA), a huge, 64 element array of ground-based telescopes in the high Andes of Northern Chile at a cost of €0.5 billion.

This is because Europe has established itself at the forefront of mm/submm radio astronomy. It operates the largest mm and submm telescopes and the largest mm interferometer in the world ; it has built receivers for these instruments that are second to none.

Millimetre astronomy's relatively recent beginnings are due solely to the complex technical demands of the genre. Not only are high, dry mountain sites obligatory for the highest frequencies because of the absorption of mm/sub mm radiation by the atmosphere, but telescope technology and especially receiver technology has been difficult to develop and only now is it beginning to reach anything like maturity. We are still some way from optimum receiver performance even in the lower atmospheric windows (80-350 GHz), where the challenge is to build low noise receivers with the largest possible instantaneous bandwidth; and at the highest frequencies, where we n eed to develop receivers that approach the quantum noise limit. These are the main thrusts of this JRA.

The AMSTAR Principle Investigator is M. Guelin (IRAM)
guelin@iram.fr

More information can be found on the wiki page AMSTARWikiPage.