Exploring cosmic origins with CORE: mitigation of systematic effects
  We present an analysis of the main systematic effects that could impact the
measurement of CMB polarization with the proposed CORE space mission. We employ
timeline-to-map simulations to verify that the CORE instrumental set-up and
scanning strategy allow us to measure sky polarization to a level of accuracy
adequate to the mission science goals. We also show how the CORE observations
can be processed to mitigate the level of contamination by potentially worrying
systematics, including intensity-to-polarization leakage due to bandpass
mismatch, asymmetric main beams, pointing errors and correlated noise. We use
analysis techniques that are well validated on data from current missions such
as Planck to demonstrate how the residual contamination of the measurements by
these effects can be brought to a level low enough not to hamper the scientific
capability of the mission, nor significantly increase the overall error budget.
We also present a prototype of the CORE photometric calibration pipeline, based
on that used for Planck, and discuss its robustness to systematics, showing how
CORE can achieve its calibration requirements. While a fine-grained assessment
of the impact of systematics requires a level of knowledge of the system that
can only be achieved in a future study phase, the analysis presented here
strongly suggests that the main areas of concern for the CORE mission can be
addressed using existing knowledge, techniques and algorithms.
