EDP Sciences
Free access
Volume 411, Number 1, November III 2003
Special letters issue on: first science with integral
Page(s) L113 - L116
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20031209

A&A 411, L113-L116 (2003)
DOI: 10.1051/0004-6361:20031209


First identification and modelling of SPI background lines

G. Weidenspointner1, 2, 3, J. Kiener4, M. Gros5, P. Jean3, B. J. Teegarden1, C. Wunderer6, R. C. Reedy3, 7, D. Attié5, R. Diehl6, C. Ferguson8, M. J. Harris1, 2, J. Knödlseder3, P. Leleux9, V. Lonjou3, J.-P. Roques3, V. Schönfelder6, C. Shrader1, 2, S. Sturner1, 2, V. Tatischeff4 and G. Vedrenne3

1  NASA Goddard Space Flight Center, LHEA, Code 661, Greenbelt, MD 20771, USA
2  Universities Space Research Association, 7501 Forbes Blvd. #206, Seabrook, MD 20706, USA
3  Centre d'Étude Spatiale des Rayonnements, 9 avenue Colonel Roche, 31028 Toulouse Cedex 4, France
4  CSNSM, IN2P3-CNRS and Université Paris-Sud, 91405 Orsay, France
5  DSM/DAPNIA/SAp, Centre d'Études Nucléaires de Saclay, 91191 Gif-sur-Yvette Cedex, France
6  Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, 85740 Garching, Germany
7  University of New Mexico, Albuquerque, NM 87131, USA
8  Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK
9  Institut de Physique Nucléaire, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium

(Received 16 July 2003 / Accepted 4 August 2003)

On Oct. 17, 2002, the ESA INTEGRAL observatory was launched into a highly elliptical orbit. SPI, a high resolution Ge spectrometer covering an energy range of 20-8000 keV, is one of its two main instruments. We use data recorded early in the mission (i.e. in March 2003) to characterize the instrumental background, in particular the many gamma-ray lines produced by cosmic-ray interactions in the instrument and spacecraft materials. More than 300 lines and spectral features are observed, for about 220 of which we provide identifications. An electronic version of this list, which will be updated continuously, is available for download at CESR. We also report first results from our efforts to model these lines by ab initio Monte Carlo simulation.

Key words: line: identification -- instrumentation: miscellaneous -- methods: data analysis -- methods: numerical

Offprint request: G. Weidenspointner, Georg.Weidenspointner@cesr.fr

© ESO 2003