GREAT

GREAT Instrument Cryo Loading

German REceiver for Astronomy at Terahertz Frequencies (GREAT)

Principal Investigator class Science Instrument
Principal Investigator: 
Jürgen Stutzki
University of Cologne
Instrument Team Website

GREAT is a dual channel heterodyne instrument that will provide high resolution spectra (up to R=108) in several frequency windows in the 0.490–4.747 THz range. The front-end unit consists of two independent dewars, each containing a set of mixers. Offered for Cycle 8 are is the seven-beam array upGREAT in its Low Frequency Array configuration for the [CII] line at 158 μm and High Frequency Array configuration for the [OI] line. Also available for Cycle 8 are all four 4GREAT bands at the following frequency ranges: 490–635 GHz (Herschel/HIFI band 1), 890–1100 GHz (Herschel/HIFI band 4), 1200–1500 GHz (GREAT L1 channel), and 2490–2590 GHz (GREAT M channel). The backend for each mixer is a Fast Fourier Transform spectrometer (XFFTS). Each XFFTS has 2 GHz bandwidth and 64,000 channels providing a resolution of 44 kHz. The beam size of GREAT is diffraction limited (14.1” at 158 μm).

Examples of GREAT scientific observations and summary of specifications: GREAT Flyer

Information applicable to the observing cycles can be found in their respective versions of the Observer's HandbookBe sure that you are referencing the correct version of the handbook! 

Primary Reference:
Use when citing SOFIA/GREAT results.

"The upGREAT Dual Frequency Heterodyne Arrays for SOFIA"
Risacher, et al., 2018, JAI, 7, 1840014.
DOI: 10.1142/S2251171718400147; ADS Bibliographic Code: 2018JAI.....740014R

Additional References:

"GREAT: The SOFIA High-frequency Heterodyne Instrument"
Heyminck, S., et al., 2012, A&A, 542, L1.
DOI: 10.1051/0004-6361/201218811

"GREAT: A First light instrument for SOFIA"
Heyminck et al., 2008, ProcSPIE, 7014, 701410.
DOI: 10.1117/12.788273

Graf et al., "GREAT: the German first light heterodyne instrument for SOFIA," Infrared Spaceborne Remote Sensing and Instrumentation XV, Marija Strojnik-Scholl, Editor, Proc. SPIE 6678, 66780K (2007), DOI: 10.1117/12.768027

Wagner-Gentner et al., "GREAT optics," Millimeter and Submillimeter Detectors for Astronomy II, Jonas Zmuidzinas, Wayne S. Holland, & Stafford Withington, Editors, Proc. SPIE 5498, 464 (2004), DOI: 10.1117/12.551236

Güsten, et al., "GREAT: the first-generation German heterodyne receiver for SOFIA," Airborne Telescope Systems, Ramsey K. Melugin & Hans-Peter Roeser, Editors, Proc. SPIE 4014, 23 (2000), DOI: 10.1117/12.389122 [pdf]

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