lbj-wade / morse

MORSE

MORSE is a post-processing code that transforms a posterior distribution on neutron star masses and radii to a posterior distribution on equation of state (EoS) parameters. Effectively there are two parts to the code:

• The first part calculates a mass-radius curve given an EoS by solving the relativistic stellar structure equations (TOV- equations)
• The second part transforms a joint posterior distribution on neutron star masses and radii to a posterior distribution on EoS parameters in a Bayesian framework.

In the "Example" Ipython Notebook we show how to use MORSE to calculate mass, radius and moment of inertia from a set of EoS parameters and how to create input joint posteriors on mass and radius.

To infer a posterior distribution on EoS parameters, the following codes have to be executed:

• python Generate_Params_Par.py -n 20

The "-n 20" means that for each of the EoS parameters, 20 different values are calculated.

• python Create_MRcurves_Par.py -f1 MRIcurves20 -f2 Parameters20

This will create the mass-radius curves and the corresponding parameters and saves them as "MRIcurves20.npy" and "Parameters20.npy" respectively.

• python JacobianRho.py -f JacobianRho20 -i1 MRIcurves20.npy -i2 Parameters20.npy

This will calculate the Jacobian using the files "MRIcurves20.npy" and "Parameters20.npy". The Jacobian is saved as "JacobianRho20.npy".

• python PosteriorProbRho.py -f ProbFPS -i1 MRIcurves20.npy -i2 JacobianRho20.npy -i3 auxfiles/ObservablesFPS.npy

This will calculate the posterior distribution on the EoS parameters and save it as "ProbFPS.npy". The input posterior on masses and radii is given by the file "ObservablesFPS.npy".