Electrically charged supermassive twin stars

TL;DR

This study explores how electric charge influences the properties of supermassive twin stars with a phase transition, showing that charge can increase their maximum mass beyond previous limits.

Contribution

It introduces the first analysis of charged hybrid neutron stars with a sharp phase transition, demonstrating that electric charge can significantly increase their maximum mass.

Findings

Charged twin stars can surpass 2 solar masses, exceeding the PSR J0740+6620 constraint.

Electric charge enhances the maximum mass of hybrid stars with a phase transition.

Charged models can reach masses higher than the GW190814 compact object.

Abstract

By assuming that ultra dense hybrid neutron stars are endowed with a distribution of electric charge, we study the corresponding twin star solutions and their properties resulting from a sharp first order transition from confined hadronic to a deconfined quark phase. Two distinct quark matter equations of state with increasing stiffness are considered and the values for the maximum gravitational masses of the hadronic and hybrid twin configurations are obtained for different values of the total electric charge. Interestingly, our calculations indicate that sharp transitions make charged twin hybrid stars more massive than their neutral counterparts, and that the {$\SI{2}{M_{\odot}}$ constraint from PSR J0740+6620} is surpassed for standard values of electric charge and can be considered stable only satisfying $\partial M/\partial \epsilon_0 > 0$. In particular, our charged stellar models reach masses even higher than the unknown compact object measured in the GW190814 event.