We utilize the joint capabilities of IBIS and SPI to perform a state-resolved 20--2000\,keV analysis of the microquasar Cygnus X-1. In both LHS and HSS, the spectral analysis reveals the presence of a high-energy tail above 400\,keV in addition to a standard, Compton-like continuum in the 20--400\,keV range. We study the polarisation properties of the hard X-ray radiation, as well as of the polarisation of this high-energy tail. Polarisation is detected in the LHS in agreement with previous work. We find potential variations of the LHS polarisation with time and no polarisation detection in the HSS.
@article{arxiv.1904.09112,
title = {Long-term spectral study of the black hole Cygnus X-1 using INTEGRAL},
author = {F. Cangemi and T. Beuchert and T. Siegert and V. Grinberg and J. Wilms and J. Rodriguez and I. Kreykenbohm and P. Laurent and K. Pottschmidt},
journal= {arXiv preprint arXiv:1904.09112},
year = {2019}
}