Herschel SPIRE Fourier Transform Spectrometer: Calibration of its Bright-source Mode

Nanyao Lu; Edward T. Polehampton; Bruce M. Swinyard; Dominique Benielli; Trevor Fulton; Rosalind Hopwood; Peter Imhof; Tanya Lim; Nicola Marchili; David A. Naylor; Bernhard Schulz; Sunil Sidher; Ivan Valtchanov

doi:10.1007/s10686-013-9359-9

arXiv · 1401.2045

Herschel SPIRE Fourier Transform Spectrometer: Calibration of its Bright-source Mode

Nanyao Lu·Edward T. Polehampton·Bruce M. Swinyard·Dominique Benielli·Trevor Fulton·Rosalind Hopwood·Peter Imhof·Tanya Lim·Nicola Marchili·David A. Naylor·Bernhard Schulz·Sunil Sidher·Ivan Valtchanov

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Abstract

The Fourier Transform Spectrometer (FTS) of the Spectral and Photometric Imaging REceiver (SPIRE) on board the ESA Herschel Space Observatory has two detector setting modes: (a) a nominal mode, which is optimized for observing moderately bright to faint astronomical targets, and (b) a bright-source mode recommended for sources significantly brighter than 500 Jy, within the SPIRE FTS bandwidth of 446.7-1544 GHz (or 194-671 microns in wavelength), which employs a reduced detector responsivity and out-of-phase analog signal amplifier/demodulator. We address in detail the calibration issues unique to the bright-source mode, describe the integration of the bright-mode data processing into the existing pipeline for the nominal mode, and show that the flux calibration accuracy of the bright-source mode is generally within 2% of that of the nominal mode, and that the bright-source mode is 3 to 4 times less sensitive than the nominal mode.

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Nanyao Lu, Edward T. Polehampton, Bruce M. Swinyard, Dominique Benielli, Trevor Fulton, Rosalind Hopwood, Peter Imhof, Tanya Lim, Nicola Marchili, David A. Naylor, Bernhard Schulz, Sunil Sidher, Ivan Valtchanov. 2014-01-09. Herschel SPIRE Fourier Transform Spectrometer: Calibration of its Bright-source Mode. https://doi.org/10.1007/s10686-013-9359-9

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