Wayne - A Simulator for HST WFC3 IR Grism Spectroscopy

Wayne is an algorithm that simulates Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) grism spectroscopic frames including sources of noise and systematics. It can simulate both staring and spatial scan modes, and observations such as the transit and the eclipse of an exoplanet. Unlike many other instrument simulators, the focus of Wayne is on creating frames with realistic systematics in order to test the effectiveness of different data analysis methods in a variety of different scenarios. This approach is critical for method validation and optimising observing strategies. In this paper we describe the implementation of Wayne for WFC3 in the near-infrared channel with the G102 and G141 grisms. We compare the simulations to real data, obtained for the exoplanet HD 209458 b to verify the accuracy of the simulation. The software is now available as open source at https://github.com/ucl-exoplanets/wayne.