FIFI-LS: The facility far-infrared spectrometer for SOFIA

Randolf Klein, Simon Beckmann, Aaron Bryant, Sebastian Colditz, Christian Fischer, Fabio Fumi, Norbert Geis, Rainer Hönle, Alfred Krabbe, Leslie Looney, Albrecht Poglitsch, Walfried Raab, Felix Rebell, Maureen Savage

Research output: Chapter in Book/Report/Conference proceedingConference contribution


FIFI-LS is the German far-infrared integral field spectrometer for the SOFIA airborne observatory. The instrument offers medium resolution spectroscopy (R ∼ a few 1000) in the far-infrared with two independent spectrometers covering 50-110 and 100-200 μm. The integral field units of the two spectrometers obtain spectra covering concentric square fields-of-views sized 3000and 6000, respectively. Both spectrometers can observe simultaneously at any wavelength in their ranges making efficient mapping of far-infrared lines possible. FIFI-LS has been commissioned at the airborne observatory SOFIA as a PI instrument in spring 2014. During 2015, the commissioning as facility instrument will be complete and the SOFIA observatory will take over the operation of FIFI-LS. The instrument can already be used by the community. Primary science cases are the study of the galactic and extra-galactic interstellar medium and its processes. In this presentation, the capabilities of FIFI-LS on the SOFIA telescope will be explained and how they are used by the offered observing modes. The remaining atmosphere and the warm telescope create a high background situation, which requires a differential measurement technique. This is achieved by SOFIA's chopping secondary mirror and nodding the telescope. Depending on the source size, different observing modes may be used to observe a source. All modes use spatial and spectral dithering. The resulting data products will be 3D-data cubes. The observing parameters will be specified using AOTs, like the other SOFIA instruments, and created via the tool SSPOT which is similar to the Spitzer Space Telescope SPOT tool. The observations will be done in service mode, but SOFIA invites a few investigators to fly onboard SOFIA during (part of) their observations.

Original languageEnglish (US)
Title of host publicationGround-Based and Airborne Instrumentation for Astronomy V
EditorsSuzanne K. Ramsay, Ian S. McLean, Hideki Takami
ISBN (Electronic)9780819496157
StatePublished - 2014
EventGround-Based and Airborne Instrumentation for Astronomy V - Montreal, Canada
Duration: Jun 22 2014Jun 26 2014

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherGround-Based and Airborne Instrumentation for Astronomy V

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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