Tides in merging neutron stars: Consistency of the GW170817 event with experimental data on finite nuclei

The agreement of the nuclear equation of state (EOS) deduced from the GW170817-based tidal deformability with the one obtained from empirical data on microscopic nuclei is examined. It is found that suitably chosen experimental data on isoscalar and isovector modes of nuclear excitations together with the observed maximum neutron star mass constrain the EOS which displays a very good congruence with the GW170817 inspired one. The giant resonances in nuclei are found to be instrumental in limiting the tidal deformability parameter and the radius of a neutron star in somewhat narrower bounds. At the $1\sigma$ level, the values of the canonical tidal deformability ${\mathrm{\Lambda }}_{1.4}$ and the neutron star radius $R_{1.4}$ come out to be $267\pm 144$ and $11.6\pm 1.0$ km, respectively.

Figure 1

The maximum neutron star mass $M_{\mathrm{NS}}^{\max }$ versus the tidal deformability parameter ${\mathrm{\Lambda }}_{1.4}$ obtained from the 28 selected EDFs. The red dashed lines refer to $1.97M_{\odot }$, the observed lower bound for $M_{\mathrm{NS}}^{\max }$ . For more details, see text.

Figure 2

Correlation of $E_{\mathrm{GDR}}^{\mathrm{p}}$ and $M_{\mathrm{NS}}^{\max }$ obtained using (a) the set of selected models as in Fig. 1 with effective mass $m_0^{*}/m$ in the range 0.65–0.75 and (b) a set of systematically varied models with chosen fixed effective masses in the present work.

Figure 3

Pressure of $\beta$-equilibrated neutron star matter displayed as a function of density. The shaded region represents the constraints from the GW170817 event (B.P. Abbott et. al 2018: [13]).