Letter to the Editor

SPI-specific analysis method and software overview

¹ Max-Planck-Institut für extraterrestrische Physik, 85741 Garching, Germany
² Centre d'Étude Spatiale des Rayonnements, 31028 Toulouse, France
³ Integral Science Data Center, 1290 Versoix, Switzerland
⁴ Institut für Astronomie und Astrophysik, Universität Tübingen, 72076 Tübingen, Germany
⁵ University of Birmingham, Birmingham, UK
⁶ DSM/DAPNIA/Service d'Astrophysique, CEA Saclay, 91191 Gif-Sur-Yvette, France
⁷ NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
⁸ Universities Space Research Association, Seabrook, MD 20706, USA

Corresponding author: R. Diehl, rod@mpe.mpg.de

Received: 15 July 2003
Accepted: 4 September 2003

Abstract

The SPI spectrometer on INTEGRAL features a camera system with 19 Ge detector modules, imaging photons through a tungsten coded mask. Background is reduced by an anticoincidence detector system surrounding these. The specifics of this instrument lead to data correction and analysis methods which are described here. Raw data for science analysis are detector event messages and spectra for different categories of detector hits and pulse shapes. Preprocessing combines calibrated spectra from these, which are then interpreted using the imaging and spectral response function for measured spectra where parts of the detector plane are occulted by the mask. Background dominates the overall signal, tailored background estimates and models are based on instrument-specific signatures, their correlations, and trends.