Calibration strategy for the SPICA/SAFARI instrument

TL;DR

This paper discusses the calibration strategy for the SPICA/SAFARI infrared spectrometer, crucial for ensuring precise spectral and flux measurements in space-based observations of cosmic phenomena.

Contribution

It presents a detailed calibration approach that influences the instrument design and aims to achieve high spectral and flux calibration accuracy for SAFARI.

Findings

Calibration strategy ensures <1% spectral calibration accuracy

Achieves 1% relative flux calibration and 10% absolute flux calibration

Impacts instrument design to meet calibration requirements

Abstract

SPICA is a mid to far infra-red space mission to explore the processes that form galaxies, stars and planets. SPICA/SAFARI is the far infrared spectrometer that provides near-background limited observations between 34 and 230 micrometers. The core of SAFARI consists of 4 grating modules, dispersing light onto 5 arrays of TES detectors per module. The grating modules provide low resolution (250) instantaneous spectra over the entire wavelength range. The high resolution (1500 to 12000) mode is accomplished by placing a Fourier Transform Spectrometer (FTS) in front of the gratings. Each grating module detector sees an interferogram from which the high resolution spectrum can be constructed. SAFARI data will be a convolution of complex spectral, temporal and spatial information. Along with spectral calibration accuracy of <1%, a relative flux calibration of 1% and an absolute flux calibration accuracy of 10% are required. This paper will discuss the calibration strategy and its impact on the instrument design of SAFARI