Modélisation d'observations spectroscopiques, résolues en phase, d'exoplanètes de type Jupiter chaudes avec NIRISS à bord du télescope spatial JWST
We present simulations of infrared spectroscopic observations of the phase curve of exoplanets in transit with the Near-Infrared Imager and Slitless Spectrograph (NIRISS) in the Single-Object Slitless Spectroscopy mode (SOSS) in order to determine which systems can provide positive detections of phase modulation and which planetary parameters can and cannot be constrained by the observations. We combine emission spectra, based on a model for brown dwarf, BT-Settl, modulated by the phase of a planet around its host star, as well as reflection spectra of the star light. Given our knowledge of NIRISS, photon noise and read noise are added to the simulated observations.  We assume that the planet is a hot Jupiter that can be modeled in two ways.  A first model uses two temperatures, each characterizing one of the hemispheres of the exoplanet, which values are of the order of 10^3 K. These simulated observations are then compared to theoretical models to constrain the temperature of the planet. A simulation for WASP-43b (a exoplanet found by the Wide-Angle Search for Planets program) shows that the temperatures of its hemispheres can be constrained to better than 50 K.  A second model uses several temperatures according to a distribution in ``orange slices". The algorithms developed may also adjust the hot hemisphere phase shift on the exoplanet, the albedo of the exoplanet and the variability of the star. Simulations show that these temperatures can be constrained, for WASP-43b and HD-189733b, with an uncertainty of 200 K and, for WASP-19b, with one of 350 K.
James Webb simulations infrared phase curve short period Hot Jupiter