Location of BNS mergers predicted by our models. Top: projected offsets of BNS mergers in physical units. The dashed and dotted lines indicate the locations of SN1 and SN2, respectively, while the remaining lines represent the BNS merger offsets divided in log-spaced time bins. The shaded vertical band indicates the observed projected offset of GW 170817. Bottom: host-normalised offsets of BNS mergers with delay times between 5 and 13 Gyr (thick solid lines). This time bin matches the age of possible GW 170817 progenitors. The thin lines show the distribution of merger offsets produced by BNSs where the neutron stars received a small natal kick, v_k, of 30 km s⁻¹ at SN2. The dashed line represents the distribution of normalised offsets for the SGRBs in the BRIGHT catalogue (Fong et al. 2022; Nugent et al. 2022) with a host galaxy more massive than NGC 4993 (the shaded region indicates the offsets’ uncertainties). The vertical lines labelled with P_ch identify the normalised offsets at which the probability of chance alignment, P_ch (Bloom et al. 2002), with each galaxy is either 1, 5, or 10%.