Binary Neutron Stars Merger Simulations (2016)


Here you can find the companion movies of our work on (multi orbits) the simulation of Binary Neutron Stars using different equation of state. More dettails can be fond on the following publication: F. Maione, R. De Pietri, A. Feo and F. Loeffler, Binary neutron star merger simulations with different initial orbital frequency and equation of state. arXiv:1605.03424.

Movies of the final stage of Binary Neutron Star merger

Here you can find the movies of the evoultion of the final stage of the merger of equal-mass Neutron Stars Binary systems of Barionic mass 1.4 M from an initial separation of 60 km. The four evolution are done using four different zero temperarure nuclear equation of state (EOS) approximated by 7 politropic segments. The initial state has been generated using the LORENE code and one can see that initil orbits are eccentric and the estimated eccentricity of the oribits are, in decreasing order of star compactness: (1) e=0.028 for the APR4 EOS; (2) e=0.025 for the SLy EOS; (3) e=0.012 for the H4 EOS; (4) e=0.014 for the MS1 EOS.


APR4 EOS:


SLy EOS:


H4 EOS:


MS1 EOS:


Back ground material

The investigation has been done using only publicly available open source software, in particular, the Einstein Toolkit code deployed for the dynamical evolution and the LORENE code for the generation of the initial models. All of the source code and parameters used for the simulations have been made publicly available. This not only makes possible to re-run and re-analyze our data; it also enables others to directly build upon this work for future research.

The modified code as well as the post processing (Python) scripts can be download from the SVN server:
svn --username=anonymous checkout https://einstein.pr.infn.it/svn/numrel/pub/ #(passwd: anon)

We kindly ask to cite ( Phys. Rev. D 93, 064047, arXiv:1509.08804) and (arXiv:1605.03424)) if you find any of the material here useful for your own research.

Instructions

In order to checkout the source code necessary to re-run our simulations, use the GetComponents script:

  ./GetComponents https://einstein.pr.infn.it/gravity/Research/BNS2015.th
  

Compiling the Einstein Toolkit is outside of the scope of this document, but the following tutorial might help: Einstein Toolkit New Users Tutorial.