The upGREAT Dual Frequency Heterodyne Arrays for SOFIA

  • 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 R≳107) 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 2×7 2×7 pixels (dual polarization), and presently covers the 1.83–2.07 THz frequency range, which allows to observe the [CII] and [OI] lines at 158 μ μm and 145 μ μm wavelengths. The high frequency array (HFA) covers the [OI] line at 63 μ μm 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.

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Metadaten
Document Type:Article
Language:English
Parent Title (English):J. Astron. Instrum. (Journal of Astronomical Instrumentation)
Volume:07
Issue:04
First Page:1840014
ISSN:2251-1717
DOI:https://doi.org/10.1142/S2251171718400147
Publisher:World Scientific
Date of first publication:2018/12/03
Tag:SOFIA (GREAT); THz astronomy; airborne; high resolution spectroscopy
Departments, institutes and facilities:Fachbereich Elektrotechnik, Maschinenbau, Technikjournalismus
Dewey Decimal Classification (DDC):5 Naturwissenschaften und Mathematik / 52 Astronomie / 520 Astronomie und zugeordnete Wissenschaften
Entry in this database:2019/01/09