Herschel SPIRE FTS telescope model correction
Abstract
Emission from the Herschel telescope is the dominant source of radiation for the majority of SPIRE Fourier transform spectrometer (FTS) observations, despite the exceptionally low emissivity of the primary and secondary mirrors. Accurate modelling and removal of the telescope contribution is, therefore, an important and challenging aspect of FTS calibration and data reduction pipeline. A dust-contaminated telescope model with time invariant mirror emissivity was adopted before the Herschel launch. However, measured FTS spectra show a clear evolution of the telescope contribution over the mission and strong need for a correction to the standard telescope model in order to reduce residual background (of up to 7 Jy) in the final data products. Systematic changes in observations of dark sky, taken over the course of the mission, provide a measure of the evolution between observed telescope emission and the telescope model. These dark sky observations have been used to derive a time dependent correction to the telescope emissivity that reduces the systematic error in the continuum of the final FTS spectra to ∼0.35 Jy.
Additional Information
© 2013 Springer Science+Business Media Dordrecht. Received: 30 June 2013; Accepted: 22 September 2013; Published online: 12 October 2013. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. SPIRE has been developed by a consortium of institutes led by Cardiff University (UK) and including Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, Univ. Sussex (UK); and Caltech, JPL, NHSC, Univ. Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC (UK); and NASA (USA).Attached Files
Submitted - 1401.2047v1.pdf
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Additional details
- Eprint ID
- 49047
- DOI
- 10.1007/s10686-013-9355-0
- Resolver ID
- CaltechAUTHORS:20140829-084007888
- Canadian Space Agency (CSA)
- National Astronomical Observatories, Chinese Academy of Sciences (NAOC)
- Commissariat à l'Energie Atomique (CEA)
- Centre National d'Études Spatiales (CNES)
- Centre National de la Recherche Scientifique (CNRS)
- Agenzia Spaziale Italiana (ASI)
- Ministerio de Ciencia e Innovación (MCINN)
- Swedish National Space Board (SNSB)
- Science and Technology Facilities Council (STFC)
- NASA
- Created
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2014-08-29Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field