Nuclear constraints on the core-crust transition and crustal fraction of moment of inertia of neutron stars

Abstract

The crustal fraction of moment of inertia in neutron stars is calculated using β-equilibrated nuclear matter obtained from density dependent M3Y effective interaction. The transition density, pressure and proton fraction at the inner edge separating the liquid core from the solid crust of the neutron stars determined from the thermodynamic stability conditions are found to be ρt = 0.0938 fm −3 , Pt = 0.5006 MeV fm −3 and x p(t) = 0.0308, respectively. The crustal fraction of the moment of inertia can be extracted from studying pulsar glitches and is most sensitive to the pressure as well as density at the transition from the crust to the core. These results for pressure and density at core-crust transition together with the observed minimum crustal fraction of the total moment of inertia provide a new limit for the radius of the Vela pulsar: R ≥ 4.10 + 3.36M/M⊙ kms.

Crustal moment of inertia of glitching pulsars with the KDE0v1 Skyrme interaction

“…The extracted value of the crustal fraction of total moment of inertia, ∆I I > 1.4%, from the observed glitches in vela-pulsar allows us to limit the radius of vela pulsar to R ≥3.69+3.44M/M ⊙ . The calculation also suggest, as can be seen from table 2, that the crustal fraction of total moment of inertia can be as large as 3.6% due to crustal entrainment which is in agreement with Simple Effective Interaction [20] and Density Dependent M3Y interaction [33].…”

Gravitational waves from isolated neutron stars: Mass dependence of r -mode instability

“…This is then plotted in the same figure for ∆I I equal to 0.014. For Vela pulsar, the constraint ∆I I > 1.4% implies that allowed mass-radius lie to the right of the line defined by ∆I I = 0.014 (for ρ t = 0.0938 fm −3 and P t = 0.5006 MeV fm −3 ) [68]. The newer observational data [69] on Vela pulsar claims slightly higher estimate for ∆I I > 1.6% based on glitch activity.…”

Mass-Radius Relationship of Neutron Stars Admixed with Fermionic Asymmetric Dark Matter

“…Using the usual values of α=0.005 MeV −1 for the parameter of energy dependence of the zero range potential and n=2/3, the values obtained for the constants of density dependence C and β and the SNM incompressibility K ∞ are 2.2497, 1.5934 fm 2 and 274.7 MeV, respectively. The saturation energy per nucleon is the volume energy coefficient and the value of -15.26±0.52 MeV covers, more or less, the entire range of values obtained for a v for which now the values of C=2.2497±0.0420, β=1.5934±0.0085 fm 2 and the SNM incompressibility K ∞ =274.7±7.4 MeV [8,9].…”