The host galaxies of double compact objects across cosmic time

Understand

We explore the host galaxies of compact-object binaries (black hole--black hole binaries, BHBs; neutron star--black hole binaries, NSBHs; double-neutron stars; DNSs) across cosmic time, by means of population-synthesis simulations combined with the Illustris cosmological simulation.

• At high redshift ($z\gtrsim{}4$) the host galaxies of BHBs, NSBHs and DNSs are very similar and are predominantly low-mass galaxies (stellar mass $M<10^{11}$ M$_\odot$).
• If $z\gtrsim{}4$ most compact objects form and merge in the same galaxy, with a short delay time.
• At low redshift ($z\leq{}2$), the host galaxy populations of DNSs differ significantly from the host galaxies of both BHBs and NSBHs.