GW170817 and GW190814: tension on the maximum mass

Understand

The detection of the binary events GW170817 and GW190814 has provided invaluable constraints on the maximum mass of nonrotating configurations of neutron stars, $M_{_{\rm TOV}}$.

• However, the large differences in the neutron-star masses measured in GW170817 and GW190814 has also lead to a significant tension between the predictions for such maximum masses, with GW170817 suggesting that $M_{_{\rm TOV}} \lesssim 2.3\,M_{\odot}$, and GW190814 requiring $M_{_{\rm TOV}} \gtrsim 2.5\,M_{\odot}$ if the secondary was a (non- or slowly rotating) neutron star at merger.
• Using a genetic algorithm, we sample the multidimensional space of parameters spanned by gravitational-wave and astronomical observations associated with GW170817.
• Consistent with previous estimates, we find that all of the physical quantities are in agreement with the observations if the maximum mass is in the range $M_{_{\rm TOV}} = 2.210^{+0.116}_{-0.123} \,M_{\odot}$ within a $2\textrm{-}\sigma$ confidence level.