The host galaxies of double compact objects merging in the local
  Universe
  We investigate the host galaxies of compact objects merging in the local
Universe, by combining the results of binary population-synthesis simulations
with the Illustris cosmological box. Double neutron stars (DNSs) merging in the
local Universe tend to form in massive galaxies (with stellar mass $>10^{9}$
M$_\odot$) and to merge in the same galaxy where they formed, with a short
delay time between the formation of the progenitor stars and the DNS merger. In
contrast, double black holes (DBHs) and black hole $-$ neutron star binaries
(BHNSs) form preferentially in small galaxies (with stellar mass $<10^{10}$
M$_\odot$) and merge either in small or in larger galaxies, with a long delay
time. This result is an effect of metallicity: merging DBHs and BHNSs form
preferentially from metal-poor progenitors ($Z\leq{}0.1$ Z$_\odot$), which are
more common in high-redshift galaxies and in local dwarf galaxies, whereas
merging DNSs are only mildly sensitive to progenitor's metallicity and thus are
more abundant in massive galaxies nowadays. The mass range of DNS hosts we
predict in this work is consistent with the mass range of short gamma-ray burst
hosts.
