Research Note

Ten years of INTEGRAL observations of the hard X-ray emission from SGR 1900+14

¹ Institut für Astronomie und Astrophysik, Eberhard Karls Universität, Sand 1, 72076 Tübingen, Germany
e-mail: ducci@astro.uni-tuebingen.de
² ISDC Data Center for Astrophysics, Université de Genève, 16 chemin d’Écogia, 1290 Versoix, Switzerland
³ INAF–Istituto di Astrofisica Spaziale e Fisica Cosmica, via E. Bassini 15, 20133 Milano, Italy
⁴ AIM (UMR 7158 CEA/DSM-CNRS-Université Paris Diderot) Irfu/Service d’Astrophysique, Saclay, 91191 Gif-sur-Yvette Cedex, France

Received: 21 July 2015
Accepted: 4 October 2015

Abstract

We exploited the high sensitivity of the INTEGRAL IBIS/ISGRI instrument to study the persistent hard X-ray emission of the soft gamma-ray repeater SGR 1900+14, based on ~11.6 Ms of archival data. The 22−150 keV INTEGRAL spectrum can be well fitted by a power law with photon index 1.9 ± 0.3 and flux F_x = (1.11 ± 0.17) × 10^-11 erg cm^-2 s^-1 (20−100 keV). A comparison with the 20−100 keV flux measured in 1997 with BeppoSAX, and possibly associated with SGR 1900+14, shows a luminosity decrease by a factor of ~5. The slope of the power law above 20 keV is consistent within the uncertainties with that of SGR 1806−20, the other persistent soft gamma-ray repeater for which a hard X-ray emission extending up to 150 keV has been reported.