NFIRAOS High-Contrast Exoplanet Imaging Capabilities
Christian Marois, Jean-Pierre Veran
The TMT offers great potential to find and study nearby planetary systems, possibly imaging down to super-Earth size planets or still accreting distant planets in very young star forming regions. Since no first generation dedicated exoplanet finding instruments have been selected, initial direct exoplanet imaging will have to rely on the NFIRAOS facility AO system. I will present end-to-end Fresnel NFIRAOS simulations using its current optical design to evaluate its multi-wavelength high-contrast imaging capabilities. Long exposures have been simulated using the expected AO-delivered phase screens and the estimated speckle lifetime. It is shown that NFIRAOS will offer contrasts comparable to GPI (an optimized NIR planet-finding instrument that will soon be installed on the Gemini South 8-m telescope). Without coronograph and higher order correction, NFIRAOS will not be able to achieve high contrast at very small IWA, which are potentially accessible with a 30-meter telescope. However, TMT, with its larger aperture and better angular resolution, will acquire higher SNR planet spectra and will achieve an astrometric accuracy three times smaller than GPI, resulting in better atmospheric characterization and faster orbital parameters determination.