This is a joint project between many participants, centred around mock data from Douglas Heggie’s N-body simulation of M4. The idea is to fit the M4 mock data with various mass modelling techniques and compare the results obtained with these different methods.

M4 mock data can be found here.

Some preliminary results from GCIII are shown here

The current plan is to turn this M4 challenge into one ‘Gaia Challenge' paper (coordinated by V. Henault-Brunet), with contributions from the following people/methods (others welcome too):

- Jeans modelling (Laura & Antonio - each with their own code) - Multi-mass models with full mass function and SSP model (Vincent) - Three-component multi-mass models (Mark) - Single-mass models (Mark/Alice) - Single-mass models with potential escapers (Ian)