Dependence of pulsar death line on the equation of state

TL;DR

This paper explores how the equation of state affects the pulsar death line in the P–Pdot diagram, revealing potential links between different neutron star types and their observational properties.

Contribution

It analyzes the impact of various equations of state on the pulsar death line and proposes connections between neutron star groups based on these effects.

Findings

Central compact objects may be small mass strange stars.

Rotating radio transients could be old pulsars near death.

PSR J2144-3933 might be a large mass pulsar over 2 solar masses.

Abstract

Pulsar death line can be defined in $P-\dot{P}$ diagram. Traditionally, radio-loud pulsars are supposed to locate above the death line where is the radio-loud region. With the development of observational equipment, the observational properties of the neutron star are remarkably diverse. In $P-\dot{P}$ diagram, some of the special sources are radio-quiet but lie above the death line. From the definition of the pulsar death line, different equation of states for neutron star or strange star results in different death lines. We discuss the influence of the equation of state on the pulsar death line and the possible link between different neutron star groups. The results show that central compact objects would be the small mass of self-bound strange stars, and rotating radio transients might be old pulsars on the verge of death. We suggest that PSR J2144-3933 is likely to be a large mass pulsar, which would be larger than $2.0\rm{M_{\odot}}$. Multiple observational facts would help us to reveal the nature of pulsars.