Exploring compact binary merger host galaxies and environments with <tt>zELDA</tt>

ABSTRACT Compact binaries such as double neutron stars or a star paired with black hole, are strong sources of gravitational waves during coalescence and also the likely progenitors various electromagnetic phenomena, notably short-duration gamma-ray bursts (SGRBs), kilonovae. In this work, we generate populations synthetic place them in galaxies from large-scale hydrodynamical galaxy evolution simulation, eagle. With our zELDA code, seeded proportion to formation rate, follow their merger using both bpass cosmic binary stellar codes. We track dynamical within host potential, estimate galactocentric distance at time merger. Finally, apply observational selection criteria allow comparison model population legacy sample SGRBs. find reasonable agreement redshift distribution (peaking 0.5 &amp;lt; z 1), morphologies, projected offsets (modal impact parameter ?10 kpc). Depending on simulation used, predict $\sim 16\!-\!35{{\ \rm per\ cent}}$ SGRB events would appear ‘host-less’, i.e. that merge high parameters have hosts fainter than detection limit (H &amp;gt; 26).