Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First light for world's largest 'thermometer camera'

06.08.2007
The world's largest bolometer camera for submillimetre astronomy is now in service at the 12-m APEX telescope, located on the 5100m high Chajnantor plateau in the Chilean Andes. LABOCA was specifically designed for the study of extremely cold astronomical objects and, with its large field of view and very high sensitivity, will open new vistas in our knowledge of how stars form and how the first galaxies emerged from the Big Bang.

"A large fraction of all the gas in the Universe has extremely cold temperatures of around minus 250 degrees Celsius, a mere 20 degrees above absolute zero," says Karl Menten, director at the Max Planck Institute for Radioastronomy (MPIfR) in Bonn, Germany, that built LABOCA. "Studying these cold clouds requires looking at the light they radiate in the submillimetre range, with very sophisticated detectors."

Astronomers use bolometers for this task, which are, in essence, thermometers. They detect incoming radiation by registering the resulting rise in temperature. More specifically, a bolometer detector consists of an extremely thin foil that absorbs the incoming light. Any change of the radiation's intensity results in a slight change in temperature of the foil, which can then be registered by sensitive electronic thermometers. To be able to measure such minute temperature fluctuations requires the bolometers to be cooled down to less than 0.3 degrees above absolute zero, that is below minus 272.85 degrees Celsius.

"Cooling to such low temperatures requires using liquid helium, which is no simple feat for an observatory located at 5100m altitude," says Carlos De Breuck, the APEX instrument scientist at ESO.

Nor is it simple to measure the weak temperature radiation of astronomical objects. Millimetre and submillimetre radiation opens a window into the enigmatic cold Universe, but the signals from space are heavily absorbed by water vapour in the Earth's atmosphere. "It is a bit as if you were trying to see stars during the day," explains Axel Weiss of the MPIfR and leader of the team that installed LABOCA on APEX.

This is why telescopes for this kind of astronomy must be built on high, dry sites, and why the 5100m high plateau at Chajnantor in the extremely dry Atacama Desert was chosen. Even under such optimal conditions the heat from Earth's atmosphere is still a hundred thousand times more intense than the tiny astronomical signals from distant galaxies. Very special software is required to filter such weak signals from the overwhelming disturbances.

LABOCA (LArge BOlometer Camera) and its associated software were developed by MPIfR. "Since so far there are no commercial applications for such instruments we have to develop them ourselves," explains Ernst Kreysa, from MPIfR and head of the group that built the new instrument.

A bolometer camera combines many tiny bolometer units into a matrix, much like the pixels are combined in a digital camera. LABOCA observes at the submillimetric wavelength of 0.87 mm, and consists of 295 channels, which are arranged in 9 concentric hexagons around a central channel. The angular resolution is 18.6 arcsec, and the total field of view is 11.4 arcmin, a remarkable size for instruments of this kind.

"The first astronomical observations with LABOCA have revealed its great potential. In particular, the large number of LABOCA's detectors is an enormous improvement over earlier instruments," says Giorgio Siringo from MPIfR and member of the LABOCA team. "LABOCA is the first camera that will allow us to map large areas on the sky with high sensitivity."

The Atacama Pathfinder Experiment (APEX) where LABOCA is installed is a new-technology 12-m telescope, based on an ALMA prototype antenna, and operating at the ALMA site. It has modified optics and an improved antenna surface accuracy, and is designed to take advantage of the excellent sky transparency working with wavelengths in the 0.2 to 1.4 mm range.

"APEX is located a mere 2 km from the centre of the future ALMA array. The new LABOCA camera will be very complementary to ALMA, as its very wide view will find thousands of galaxies which will be observed in great detail with ALMA," says De Breuck.

APEX is a collaboration between the Max Planck Institute for Radioastronomy, Onsala Space Observatory and ESO.

Henri Boffin | alfa
Further information:
http://www.eso.org/public/outreach/press-rel/pr-2007/pr-35-07.html

More articles from Physics and Astronomy:

nachricht Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie

nachricht Seeing the quantum future... literally
16.01.2017 | University of Sydney

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>