FALCO simulations of high-contrast polarimetry with the Nancy Grace Roman Space Telescope Coronagraph Instrument
Authors/Creators
- 1. SRON Netherlands Institute for Space Research
- 2. Leiden University,
- 3. Jet Propulsion Laboratory
- 4. European Southern Observator
Description
The Coronagraph Instrument of the Nancy Grace Roman Space Telescope (Roman Coronagraph) will be capable
of both total intensity and polarization measurements of circumstellar disks. The polarimetric performance is
impacted by polarization effects introduced by all mirrors before the Wollaston prisms. In this paper, we aim to
characterize these effects for the Roman Coronagraph in bands 1 and 4 using the FALCO and PROPER packages.
We simulate the effect of polarization aberrations that impact the polarimetric contrast and the instrumental
polarization effects to study the polarimetric accuracy. We include spacecraft rolls, but leave out systematic
camera noise. We find that polarimetric differential imaging (PDI) improves the contrast by a factor of six.
The PDI contrast of ∼ 8 × 10−11 is limited by polarized speckles from instrumental polarization effects and
polarization aberrations. By injecting polarized companions with at various contrast levels and demodulating
their polarimetric signal, we recover their source Stokes vectors within 2%.