Thursday, May 06, 2010

Making the invisible visible

Fig. 1: A snapshot of a stellar nursery in our home galaxy, the Milky Way: a high-mass star forming region inside the giant molecular cloud S255, about 8,000 light-years away from Earth (1 light-year is roughly 10 trillion kilometers). Such clouds are typically opaque to visible light. However, infrared light can penetrate the dust, so that the LUCIFER image reveals the cluster of newly born stars and its complex environment in all their splendour. Image: Arjan Bik

LUCIFER’s innovative design allows astronomers to observe in unprecedented detail, for example, star forming regions which are commonly hidden by dust clouds. The instrument provides unrivaled flexibility, with features such as a unique robotic arm that can replace spectroscopic masks within the instrument’s extreme sub-zero environment.

LUCIFER and its twin are mounted at the focus points of the LBT’s two giant 8.4-metre (27.6 foot) diameter telescope mirrors. Each instrument is cooled to a chilly -213 degrees Celsius in order to observe in the near-infrared (NIR) wavelength range. Near-infrared observations are essential for understanding the formation of stars and planets in our galaxy as well as revealing the secrets of the most distant and very young galaxies.

Fig. 2: The faint irregular dwarf galaxy NGC 1569, located 6.2 million light-years from Earth. This galaxy contains several large stellar clusters with episodic star formation at a rate of more than 100 times faster than we observe in our own galaxy. In visible light, the core of the galaxy shows only three large stellar clusters, each containing more than one million stars. With LUCIFER it became possible to peer through the cosmic dust and to reveal many more compact star forming regions. Image: Anna Pasquali

LUCIFER is a remarkable new multi-purpose instrument with great flexibility combining a large field of view with a high resolution. It provides three exchangeable cameras for imaging and spectroscopy in different resolutions according to observational requirements. Besides its outstanding imaging capability which presently makes use of 18 high-quality filters, LUCIFER allows the simultaneous spectroscopy of about two dozen objects in the infrared through laser-cut slit-masks. For highest flexibility the masks can be changed even at the cryogenic temperatures, through the innovative development of a unique robotic mask grabber which places the individual masks with absolute precision into the focal plane.

"Together with the large light gathering power of the LBT, astronomers are now able to collect the spectral fingerprints of the faintest and most distant objects in the universe." says Richard Green, the Director of the LBT. "After completion of the LBT adaptive secondary mirror system to correct for atmospheric perturbation, LUCIFER will show its full capability by delivering images with a quality that are otherwise only obtained from space-based observatories."

"Already the very first LUCIFER observations of star forming regions are giving us an indication of the enormous potential of the new instrument," said Thomas Henning, the chair of the German LBT-Partners.

Fig. 3: A cut-out of a multi-object spectrum obtained with LUCIFER showing the tell-tale signs of gas heated by young stars at unimaginably distances of billions of light-years. Such a spectrum is the decomposition of light into its different wavelengths (colors). At certain wavelengths, emission lines can be found depending on the chemical composition and physical conditions of an object. For distant galaxies, the most interesting lines are found in the near-infrared, where observations were less efficient until now. With LUCIFER and the LBT, large samples of galaxies can now be studied using its multi-object capability. Image: Jaron Kurk

The instruments have been built by a consortium of five German institutes led by the Center for Astronomy of Heidelberg University (Landessternwarte Heidelberg, LSW) together with the Max Planck Institute for Astronomy in Heidelberg (MPIA), the Max Planck Institute for Extraterrestrial Physics in Garching (MPE), the Astronomical Institute of the Ruhr-University in Bochum (AIRUB) as well as the University of Applied Sciences in Mannheim (Hochschule Mannheim).

Walter Seifert (LSW), Nancy Ageorges (MPE) and Marcus Jütte (AIRUB), responsible for the successful commissioning, spent more than half a year in several runs at the LBT site to make the telescope/instrument combination work efficiently. Holger Mandel, the Principal Investigator of LUCIFER said: "From the very beginning, there was uniform excitement about the promise of this instrument for cutting-edge science. Now, the amazing results speak for themselves."

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The Large Binocular Telescope (LBT) is a collaboration among the Italian astronomical community (National Institute of Astrophysics - INAF), The University of Arizona, Arizona State University, Northern Arizona University, the LBT Beteiligungsgesellschaft in Germany (Max Planck Institute for Astronomy in Heidelberg, Zentrum fur Astronomie der Universität Heidelberg, Astrophysikalisches Institut in Potsdam, Max Planck Institute for Extraterrestrial Physics in Garching (Munich), and Max Planck Institute fϋr Radio Astronomy in Bonn), The Ohio State University and Research Corporation (Ohio State University, University of Notre Dame, University of Minnesota, and University of Virginia).

Related links:

[1] Images, detailed image captions and additional technical background information

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Contact:

Prof. Dr. Thomas Henning
Max Planck Institute for Astronomy, Heidelberg
Tel.: +49 6221 528-201
E-mail:
henning@mpia.de

Dr. Klaus Jäger
Max Planck Institute for Astronomy, Heidelberg
Tel.: +49 6221 528-379
E-mail:
jaeger@mpia.de

Dr. Holger Mandel
Landessternwarte Heidelberg
Tel.: +49 6221 541-734
E-mail:
h.mandel@lsw.uni-heidelberg.de

Dr. Walter Seifert
Landessternwarte Heidelberg
Tel.: +49 6221 541-732
E-mail:
wseifert@lsw.uni-heidelberg.de