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We report on Cyg X-1 observations performed by the SPI telescope onboard theINTEGRAL mission and distributed over more than 6 years. We investigate thevariability of the intensity and spectral shape of this peculiar source in thehard X-rays domain, and more particularly up to the MeV region. We first studythe total averaged spectrum which presents the best signal to noise ratio (4 Msof data). Then, we refine our results by building mean spectra by periods andgathering those of similar hardness.  Several spectral shapes are observed with important changes in the curvaturebetween 20 and 200 keV, even at the same luminosity level. In all cases, theemission decreases sharply above 700 keV, with flux values above 1 MeV (orupper limits) well below the recently reported polarised flux (Laurent et al.2011), while compatible with the MeV emission detected some years ago byCGRO/COMPTEL (McConnell et al., 2002).  Finally, we take advantage of the spectroscopic capability of the instrumentto seek for spectral features in the 500 keV region with negative results forany significant annihilation emission on 2 ks and days timescales, as well asin the total dataset.

The emission of Cygnus X-1: observations with INTEGRAL SPI from 20 keV to 2 MeV