The Transiting Exoplanet Community Early Release Science Data Challenge #1: Lessons for NIRISS Spectroscopic Time-Series Analysis

The Transiting Exoplanet Community Early Release Science (ERS) Program produced a simulated transit of WASP-39b as would be observed by NIRISS/SOSS. The dataset was generated by Mirage and spans 0.6–2.5 μm (SUBSTRIP256) at R ~ 700. The simulation is consistent with the ERS observing plan, with 9 groups per integration and a total of 527 integrations in one exposure. Stage 0 (raw, uncalibrated frame data), Stage 1 (calibrated, ramp-fit data), and Stage 2 (flux-calibrated, extracted spectra) outputs and their corresponding reference files were delivered to the community and used as inputs at an open Data Challenge where independent analysis tools were compared at multiple stages of the process. Participants performed intercomparisons of reduced data, light curves, and transmission spectra. We describe the simulated data products and report on the lessons learned from this ERS Data Challenge regarding NIRISS/SOSS time-series spectroscopy. We describe the open-source tools currently available and outstanding challenges that drive continued development leading up to the actual JWST observations expected later in the year.