26 May 2009

Incredibly sensitive instrument ready to observe the universe

The new instrument is called the X-shooter and has now been installed at the European very large telescope, the VLT in Chile. Danish researchers from the Niels Bohr Institute have developed and built a large part of the instrument which surpasses all previous instruments in its capability for registering the entire light spectrum of an object in the universe at very high resolution and in a single image.

The X-shooter is now installed on the
European Very Large Telescope, VLT
in Chile.

Six years of work are now complete for astronomer Per Kjærgaard Rasmussen, Niels Bohr Institute, who has led the development and construction of the Danish part of the instrument, which also has contributions from Italy, the Netherlands, France and ESO.

The instrument surpasses all previous instruments of its kind in the world. Just ten years ago less than one percent of the light a supernova (exploding star) emitted in a distant galaxy could be registered. With the current instruments up to 20 percent of the light can be seen, but with the new instrument, where the utmost has been done to optimize all of the optical parts, it will be possible to observe 40-45 percent of the light.

Exploding stars and black holes
"It is simply incredible, how sensitive X-shooter is and it will give us the opportunity to get detailed images of the history of star formation in the universe", explains professor Jens Hjorth, who leads the Dark Cosmology Centre, who will use the X-shooter in several large research projects.

The instrument takes a full spectrum of light from the ultra violet
(300 nm) across the visible field of light to the near infrared
(2400 nm) light in one image.

He explains that the instrument is completely unique because it takes a full spectrum of light from the ultra violet (300 nm) across the visible to the near infrared (2400 nm) light in one image. This is very important when observing gamma-ray bursts which are intense bursts of radiation that can form in connection with a supernova explosion.

Astronomers need to observe the entire light spectrum in order to analyse the phenomenon, but today only one section of the spectrum can be observed at a time, and during that ½-1 hour period from one measurement to the next the situation may have changed completely.

With the new instrument astronomers can observe the entire light spectrum from gamma rays in the distant universe.

"That the new instrument can measure the entire spectrum at one time and at very high resolution means that we can get a complete image of even very weak objects like distant galaxies in the very early universe and perhaps get an answer to when the very first stars were formed and what kind of mechanisms cause a star to explode. The early universe looked completely different than it does now and we would like to be able to study the properties of black holes and giant nebulae", explains Jens Hjorth who describes the universe as a giant zoo waiting to be explored.

ESO press release: