SOSS Simulation Tools

by the NIRISS Instrument Team

The NIRISS Single Object Slitless Spectrograph (SOSS) 1-D Simulator:

This tool prepared by the NIRISS Instrument Team simulates spectra produced with the SOSS observing mode of NIRISS doing transit spectroscopy. It computes signal and noise from first principles, based on our best knowledge of the instrument and observatory. This is a 1-D tool, i.e., we deal with flux per pixel row extracted from the detector and assume that the extraction was done optimally, not introducing errors. We encourage the user to read the Simulator Guide.

(Version 1.0)

Here is a SOSS Simulator Guide (in pdf).

Astrophysical Inputs
Planet Name
NOTE: The resolver function is broken. Please enter the planet and star parameters manually. Make sure to enter a name *without* pressing the resolve button so that plots can be generated. OLD NOTE: To resolve, the same formatting as the NASA Exoplanet Archive might be needed (ex : CoRoT-1 b).
Planet Atmosphere Model
  Check this box to scale the model by changing the scale height using actual temperature and gravity. Otherwise, the model will directly be used.
Star Radius Rsun
Star Teff Kelvin (rounded to 100 K)
Star J Mag (Vega System)
Transit Duration hours (t_14)
Planet Density g/cm3
Planet Teq Kelvin
Planet Solid Radius
Instrument Setup and Observing Strategy
Out to In Factor (Ratio of time spent outside transit and during transit)
Number of Transits
Pixel Binning (Order 1)
Pixel Binning (Order 2) (2 for Nyquist sampling)
Noise Floor (ppm)
Sub-Array x2048
Number of Read Frames per Ramp (aka Ngroup)
Make sure to fill in the boxes before pressing the button.Running the simulation takes about 2 seconds. Patience. ...