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Equation of state dependence of neutron star mergers (EOSDNSM)
Date du début: 1 août 2013, Date de fin: 31 juil. 2015 PROJET  TERMINÉ 

Mergers of neutron stars are strong emitters of gravitational waves and are among the prime targets of the upcoming gravitational wave detectors Advanced VIRGO and LIGO. Within our proposal we aim to clarify the influence of the equation of state (EoS) of neutron star matter (still largely incompletely known) on the post-merger gravitational wave signal. Understanding the dependence on the EoS can be used to determine the properties of high-density matter via the detection of gravitational waves and we plan to exploit our recent discovery of an empirical relation for doing this. Our project relies crucially on numerical simulations of neutron star mergers with different theoretical prescriptions of the high-density EoS. By developing a theoretical model of neutron star mergers and by exploring their detectability, we will be able to set up a ready-to-use pipeline for the detection and interpretation of the post-merger gravitational wave signals. Moreover, material that becomes gravitationally unbound after merging is subject to nucleosynthetic processes. The decompression of neutron-rich matter provides excellent conditions for producing r-process elements, heavy neutron-rich elements whose astrophysical production site has not yet been identified. In a second line of our proposal, we plan to investigate the detailedconditions for r-process nucleosynthesis in neutron star mergers, determining the dependence of the amount of ejecta on the EoS. We will use data from relativistic hydrodynamical merger simulations as input for nuclear network calculations, exploring the nucleosynthesis yields. Our efforts will also reveal the properties of electromagnetic counterparts of neutron star mergers, which are powered by the radioactive decay of the synthesized elements. These transients are potentially observable with upcoming and existing optical surveys, opening the exciting possibility of multi-messenger observations.