Letter to the Editor

INTEGRAL Spectrometer SPI's GRB detection capabilities ^*

GRBs detected inside SPI's FoV and with the anticoincidence system ACS

¹ Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany,
² Institut für Astronomie und Astrophysik, Universität Tübingen, Sand 1, 72076 Tübingen, Germany
³ INTEGRAL Science Data Centre, Chemin d'Écogia 16, 1290 Versoix, Switzerland
⁴ Science Operations and Data Systems Division of ESA/ESTEC, SCI-SDG, Keplerlaan 1, Postbox 299, 2200 AG Noordwijk, The Netherlands
⁵ Department of Experimental Physics, University College Dublin, Stillorgan Road, Dublin 4, Ireland
⁶ Space Research Group, Univ. of Birmingham B15 2TT, Birmingham, UK
⁷ UC Berkeley Space Sciences Laboratory, Berkeley, CA 94720-7450, USA
⁸ Space and Remote Sensing Sciences, NIS-2 Mail Stop D436, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
⁹ Dept. of Physics, UAH, National Space Science & Technology Center, Huntsville, AL 35805, USA
¹⁰ Centre d'Études Spatiales des Rayonnements, 9 avenue du Colonel Roche, 31028 Toulouse, France,

Corresponding author: A. von Kienlin, azk@mpe.mpg.de

Received: 16 July 2003
Accepted: 8 August 2003

Abstract

The spectrometer SPI, one of the two main instruments of the INTEGRAL spacecraft, offers significant gamma-ray burst detection capabilities. In its 35° (full width) field of view SPI is able to localise gamma-ray bursts at a mean rate of ~0.8/month. With its large anticoincidence shield of 512 kg of BGO crystals SPI is able to detect gamma-ray bursts quasi omni-directionally with a very high sensitivity. Burst alerts of the anticoincidence shield are distributed by the INTEGRAL Burst Alert System. In the first 8 months of the mission about 0.8/day gamma-ray burst candidates and 0.3/day gamma-ray burst positions were obtained with the anticoincidence shield by interplanetary network triangulations with other spacecrafts.