Properties of proto neutron star PSR J0737-3039A

Abstract：

Using five sets of nucleon coupling constants (DD-MEI, GL85, GL97, GM1, and NL2), we find that the radius of the PNS PSR J0737-3039A is R=15.693–18.846 km, the central baryon density is $\rho_{\rm c}$ =0.247–0.359 fm $^{-3}$ , the central energy density is $\varepsilon_{\rm c}$ =4.30 $\times$ 10 $^{14}$ – 6.49 $\times$ 10 $^{14}$ $ \rm g\cdot cm^{-3}$ , and the central pressure is $p_{\rm c}$ =3.79 $\times$ 10 $^{34}$ – 5.85 $\times$ 10 $^{34}$ $\rm dyne\cdot cm^{-2}$ . With DD-MEI, GL85, GL97, and GM1, baryon octets appear in the PNS PSR J0737-3039A. With NL2, only the baryons n, p, Λ, $\Sigma^{0}$ , $\Sigma^{-}$ , $\Xi^{0}$ , and $\Xi^{-}$ are present. Corresponding to the same baryon density, the relative densities of the same baryon in the PNS PSR J0737-3039A calculated using different nucleon coupling constants differ greatly. The central relative baryon densities of the PNS PSR J0737-3039A calculated using different nucleon coupling constants also differ greatly.