Simulators are frequently used in astronomy to model the behaviour of a telescope and instrument, and to simulate its data products. MIRI is no exception. MIRISim is the official MIRI simulator, able to model Imager, MRS and LRS simulations. Special needs not covered by MIRISim can be answered by our centre of expertise, as several members are active developpers of the simulator.
In parallel, MICE, the French Centre of Expertise for MIRI, has developped an IDL simulator for the coronagraphs. This simulator can be used upon request and scientists who would make use of it should contact directly MICE.
It was thus decided to develop a general MIRI simulator, MIRISim, as a communicating suite of packages. This MIRI simulator is being developed in Python by the European Consortium. It will include all functionalities of the instrument, taking into account all of the detectors effects and will be distributed worldwide.
MIRISim takes as input either a user defined ‘scene’ or a FITS file, and simulates an observation based on user defined Imager filters or MRS channels, and exposure parameters (number of groups, integrations, etc). The results are JWST ‘level 1B’ data which are suitable for processing with the JWST pipeline. The data produced by MIRISim is consistent with the MIRI sensitivity model, but should not be used as a replacement for the JWST Exposure Time Calculator (ETC).
MICE has been working in simulations for the Imager and LRS in Python, with some support from outside (Stephen Beard from STFC, Örs Detre from MPIA, and Steffen Rost from the University of Cologne) for integration in the general MIRISim simulator.
A stable public version has been released August 17th 2017 for general users. However, there is a “private” version « MIRICLE » for the MIRI team and collaborators, on which MICE has been working actively (see http://miri.ster.kuleuven.be/bin/view/Internal/Software/MIRISimReleases). MICE’s work on MIRIMSim includes:
The MIRI Simulator software package, MIRISim has been released for public use on April 9, 2018.
The current version is Python 2.7 based, with a planned update to Python 3 coming soon.
To be kept up to date with MIRISim developments, including announcements of new releases, please sign up to the announcement list.
MIRISim is available on an as-is, best-effort basis, and information about MIRISim and example use cases can be found here.