Searching for Signs of Earth-Like Planets: Demonstrating the Potential of the Roman-Coronagraph in Resolving Exozodiacal Dust and Debris Disk Substructures

The high contrast imaging of habitable zone (HZ) exoplanets around our nearest stellar neighbors in reflected light is a key science objective for upcoming and proposed high contrast imaging observatories including the Roman-Coronagraph and the Habitable Worlds Observatory. Roman is expected to achieve less than 10^-8 contrast at 140 mas inner working angle, higher contrast than previous ground and space instrumentation. While this is not enough sensitivity to detect smaller terrestrial planets, Roman will be capable of resolving planet-induced substructures in ~0.1 mJy/arcsec² bright exozodiacal and inner debris rings. These systems will make for prime targets for ELTs and the HWO, which will be capable of detecting the planets that induce these atypical disk morphologies. To demonstrate this, we produce several simulations of Roman observations of debris disk systems sculpted from the influence of planetary companions, using both simple density-function disk models and more advanced dynamical disk models. We utilize a radiative transfer modeling approach to retrieve these morphological properties and assess the power of Roman in dust disk characterization and identification of planet-disk interaction features from sub-Neptunian and terrestrial planets. The results from this investigation will directly inform observing strategies and analysis approaches for future high contrast imaging instruments and are an important first step in the characterization of HZ disk structure, subsequently informing theories of planetary system architecture, dynamics, and formation.