5 years of survey on the Crab Nebula with SPI/INTEGRAL
Abstract
We present observations of the Crab Nebula above 20 keV by the SPI/INTEGRAL telescope during more than 5 years of operations. Our study demonstrates the stability of the instrument with time and allows a detailed analysis of the emission observed from the Crab Nebula between 20 keV and 1 MeV. The flux stability is discussed and serves a robust spectral shape analysis. We find that a single power law is clearly excluded since the photon spectrum presents a curvature in the considered energy domain. We have modelled it by a broken power law with the energy break fixed to 100 keV and determined the two photon indices together with the 100 keV flux for 9 periods between 2004 and 2008. The spectral shape of the Crab nebula is very stable as well as its intensity and connects nicely with previous measurements, at lower (X-rays) or higher (MeV) energies.
Keywords
Cite
@article{arxiv.0809.5018,
title = {5 years of survey on the Crab Nebula with SPI/INTEGRAL},
author = {E. Jourdain and J. P. Roques},
journal= {arXiv preprint arXiv:0809.5018},
year = {2008}
}
Comments
6 pages; Submitted to PoS for publication in the 7th INTEGRAL workshop - An INTEGRAL View of Compact Objects Proceedings