Simulation of the observation of Sgr B2 with IXPE

The combination of imaging and polarimetric capabilities over a ~8 arcmin Field of View will allow the Imaging X-ray Polarimetry Explorer (IXPE) to investigate the polarization properties of complex fields and extended sources by means of position- and energy-dependent polarization maps that will clarify the emission processes and the role of the magnetic field structure on the acceleration process in the X-ray emitting region. The SgrB2 Molecular Cloud near the Galactic center is one of the most representative targets, being faint, extended and in a crowded field. The interest in the observation of the molecular Clouds in the Galactic center lies in the opportunity to determine if their observed hard X-ray reflection spectrum is an “echo” from a past outburst of SgrA*. If this theory is true we expect the clouds to be strongly polarized (depending to their relative position to SgrA*), with a polarization angle perpendicular to the direction of the external source. We expect he intrinsic polarization degree to be diluted by the presence of a hot plasma “bubble” in which the clouds are embedded. This factor, together with the effect of the instrumental and diffuse background must be addressed. Here a simulation of a long (3 Ms) IXPE observation is presented: “ixpeobssim”, a Python based Monte Carlo code that allows to use Chandra observations in order to preserve the full correlation between the source morphology and the spectrum, is employed.