Tutorials

NMMA is capable of performing combined analyses to constrain:

• the neutron star equation of state (EOS), and
• the Hubble Constant.

In the following, we will take as an example the EOS analysis.

Generate a simulation set

First of all, you need to create an output directory, this output will host all the data that will be used to constrain the EOS.

mkdir -p ./output

Running the following command line will generate a json file (injection.json) with the BILBY processing of compact binary merging events. We take here binaries of type BNS (NSBH is also an option). This injection comprises a simulation set of parameters: luminosity_distance, log10_mej_wind, KNphi, inclination_EM, KNtimeshift, geocent_time for the Bu2019lm model. This creates an injection.json file in the ./output directory.

nmma_create_injection --prior-file ./priors/Bu2019lm.prior --eos-file ./example_files/eos/ALF2.dat --binary-type BNS -f ./output/injection --n-injection 100 --original-parameters --extension json

Light curve posterior

EM data will house the posteriors of the electromagnetic data you will produce: in particular the lc.csv (./example_files/csv_lightcurve/outdir/macroeventID, where macroeventID in range(0, 100)) light curves. We now compute posteriors using NMMA on this simulated set of 100 events, of which we assume a fraction is detectable by Zwicky Transient Facility (ZTF). The result can be find at ./output/EMdata