Unveiling the architecture of planetary systems through total and polarized intensity observations with the Roman Coronagraph
PI: Anche, Ramya, University Of Arizona
Coronagraph Community Participation Program
The Nancy Grace Roman Space Telescope Coronagraph Instrument will facilitate multiwavelength total intensity and polarimetric observations of debris disks and planetary companions around nearby stars, achieving a contrast of ≲ 10−8for the first time. These observations will be crucial for constraining the dust composition, structure, and properties of the circumstellar debris disks, as well as understanding the atmospheric composition of the planetary companions. The Astro2020 decadal survey emphasizes the importance of detecting polarization signatures of disks and ocean glint from exoplanets in addition to direct imaging. While the primary goal of the Roman Coronagraph is to meet the TTR5 requirement and demonstrate its performance in best-effort modes, the coronagraphic mission may be extended beyond the TTR5 phase to explore unsupported modes. We propose to assist the coronagraph and current CPP teams in developing high-fidelity end-to-end simulations for the required, best-effort, and unsupported modes that will enable us to obtain multiwavelength total intensity and polarized observations of planetary systems around nearby stars, thereby enhancing the science returns from the Roman Coronagraph. This proposal addresses the four aspects of the Roman CPP proposal call related to the required modes A, D, E, and G, as well as two aspects pertaining to the unsupported modes H and J.
We propose to assist the coronagraph and current CPP teams in developing high-fidelity end-to-end simulations for the required, best-effort, and unsupported modes. These simulations will enable us to obtain multiwavelength total intensity and polarized observations of planetary systems around nearby stars, thereby enhancing the science returns from the RC. This proposal addresses the six aspects of the Roman CPP proposal call related to the required modes A, B, D, E, F, and G and two aspects of the unsupported modes H and J by...
1. Developing end-to-end multiwavelength science observation simulations for circumstellar debris disks and planetary companions, which are science targets of the TTR phase. This will include HLC bands 1, 2, 3, and 4, and Shaped Pupil Coronagraph (SPC) bands 1 and 4 in both imaging and polarimetry, accounting for all relevant noise sources and uncertainties.
2. Creating data reduction pipeline functions for best-effort, unsupported imaging, and polarimetry modes and integrating these functions with the corgidrp architecture.
3. Developing end-to-end observing scenario simulations with an injected circumstellar debris disk and planetary companion that are science targets of the Roman TTR phase for HLC Band 1 in case a dark hole cannot be formed in the observation phase as a risk mitigation strategy.
Our proposed approach combines a range of open-source disk and coronagraph simulation and post-processing tools we have developed over the past six years to support the coronagraph technology demonstration and potential science missions. These include physical optics propagation of coronagraph speckles, polarimetric radiative transfer modeling of disks and planets, speckle subtraction, disk extraction, and post-processing. All output generated from these simulations will be integrated with the Roman Corgi Sim architecture and processed using the CorGi data reduction pipeline. We will collaborate closely with the CPP observation planning and DRP teams to gather input on the science and reference targets selected for the technology demonstration phase. This simulation toolset will enable optimal science target selection and planning and prepare for future possible uses of the Roman Coronagraph; in addition to regular publication and presentations, we will lay the groundwork for community engagement by thorough and regular sharing of open-source software libraries, tutorials, input data, and simulation results.