ner_tags: O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-CelestialObject O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O B-CelestialObject O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-CelestialObject O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O O O B-Citation I-Citation I-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Model I-Model I-Model O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-CelestialObject O O O B-CelestialObject O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O B-Citation O O
tokens: are heated by the nuclear decays of products of the rapid neutron-capture process (Metzger et al. 2010 ). The light-curve properties were interpreted as being produced by dynamical ejecta from the merger and secular ejecta from the merger remnant. The estimated ejecta mass is in the range of 0.03 to 0.05 (Chornock et al. 2017 ; Cowperthwaite et al. 2017 ; Drout et al. 2017 ; Kasen et al. 2017 ; Kasliwal et al. 2017 ; Kilpatrick et al. 2017 ; Nicholl et al. 2017 ; Smartt et al. 2017 ; Tanaka et al. 2017 ; Tanvir et al. 2017 ), which even for asymmetric binaries lies near the high end of the theoretical range expected from simulations. This can be interpreted as tentative evidence for a delayed/no collapse in GW170817 because this merger outcome tends to produce larger ejecta masses as compared to a direct collapse (Bauswein et al. 2013b ; Fernández Metzger 2013 ; Hotokezaka et al. 2013 ; Metzger Fernández 2014 ; Perego et al. 2014 ; Siegel et al. 2014 ; Wanajo et al. 2014 ; Just et al. 2015 ; Sekiguchi et al. 2016 ). We thus use below the assumption of no prompt collapse in GW170817 and leave the detailed interpretation of the electromagnetic emission to future work. Our assumption can be corroborated by refined models and future observations. 3. NS Radius Constraints 3.1. Threshold Binary Mass If GW170817 resulted in a delayed collapse or no collapse, its total mass provides a lower limit on the threshold binary mass for prompt collapse as given by Equation ( 1 ). The threshold binary mass M thres depends sensitively on the EoS (Shibata 2005 ; Baiotti et al. 2008 ; Hotokezaka et al. 2011 ; Bauswein et al. 2013a ). Considering different EoSs, in Bauswein et al. ( 2013a ), we found by hydrodynamical simulations that the threshold binary mass to good accuracy followswith being the radius of a nonrotating NS with a mass of 1.6 and M max being the maximum mass of nonrotating NSs. The relation was derived from simulations of symmetric binary mergers but also holds for moderately asymmetric systems (Bauswein et al. 2013a ; Bauswein Stergioulas 2017 ). We verify through additional simulations for five representative EoSs that strongly asymmetric mergers with mass ratio q = 0.6 have a threshold binary mass, which is systematically lower by 0.1 to 0.3 than M thres of equal-mass binaries. This reduction of M thres for asymmetric binaries is understandable because, according to Kepler ’s law, asymmetric binaries have less angular momentum than equal-mass binaries with the same M tot at a given orbital separation, which implies less stabilization for asymmetric mergers. (With the low-spin priors, the 90% credibility interval of the mass ratio of GW170817 is ). If GW170817 was very asymmetric, one has , which implies that Equation ( 1 ) is conservative because . A similarly accurate description of M thres is given by the fitwith the radius R max of the maximum-mass configuration. Equation ( 2 ) is accurate to better than (Bauswein et al. 2013a , 2016 ). The