1. The upGREAT Dual Frequency Heterodyne Arrays for SOFIA
- Author
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O. Ricken, Nicola Schneider, Paul Fusco, Heinz-Wilhelm Hübers, Christophe Risacher, Rolf Güsten, Heiko Richter, Timea Csengeri, J. Stutzk, Ronan Higgins, A. Bell, Urs U. Graf, Nicolas Reyes, A. Parikka, Martin Wienold, Rebeca Aladro, Helmut Wiesemeyer, Yoko Okada, Bernd Klein, P. Pütz, Stefan W. Rosner, Christof Buchbender, R. Simon, M. Mertens, Monika Ziebart, M. Justen, Denise Riquelme, K. Jacobs, Nick Rothbart, B. Wohler, Cornelia E. Honingh, C. Duran, and D. Büchel
- Subjects
Terahertz radiation ,Terahertz ,FOS: Physical sciences ,Spektroskopie ,02 engineering and technology ,01 natural sciences ,law.invention ,Telescope ,Heterodyn EdW ,Optics ,law ,Observatory ,Technik für Weltraumsysteme ,0103 physical sciences ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Instrumentation ,Physics ,THz Lokaloszillator ,Spectrometer ,business.industry ,Astronomy and Astrophysics ,Astronomie ,Cryocooler ,021001 nanoscience & nanotechnology ,Polarization (waves) ,Dual-polarization interferometry ,Dichroic filter ,ddc:520 ,Astrophysics - Instrumentation and Methods for Astrophysics ,0210 nano-technology ,business ,SOFIA - Abstract
We present the performance of the upGREAT heterodyne array receivers on the SOFIA telescope after several years of operations. This instrument is a multi-pixel high resolution (R > 10^7) spectrometer for the Stratospheric Observatory for Far-Infrared Astronomy (SOFIA). The receivers use 7-pixel subarrays configured in a hexagonal layout around a central pixel. The low frequency array receiver (LFA) has 2x7 pixels (dual polarization), and presently covers the 1.83-2.06 THz frequency range, which allows to observe the [CII] and [OI] lines at 158 um and 145 um wavelengths. The high frequency array (HFA) covers the [OI] line at 63 um and is equipped with one polarization at the moment (7 pixels, which can be upgraded in the near future with a second polarization array). The 4.7 THz array has successfully flown using two separate quantum-cascade laser local oscillators from two different groups. NASA completed the development, integration and testing of a dual-channel closed-cycle cryocooler system, with two independently operable He compressors, aboard SOFIA in early 2017 and since then, both arrays can be operated in parallel using a frequency separating dichroic mirror. This configuration is now the prime GREAT configuration and has been added to SOFIA's instrument suite since observing cycle 6., Accepted to the Journal of Astronomical Instrumentation (SOFIA Special Edition) on 12th November 2018
- Published
- 2018