Quark stars with the density-dependent quark mass model

Abstract

The recent observation of the pulsar PSR J1614-2230 with a mass of 1.97±0.04M⊙ gives a strong constraint on the equation of state (EoS) of the dense matter in compact stars. In this work, we calculate the maximum mass of quark stars with the density-dependent quark mass model, and explore the parameter ranges for this model fully, by considering the constraints of absolute stability of strange quark matter and the mass of PSR J1614-2230. Without the color-superconductivity, the maximum mass of unpaired quark stars is more sensitive to the parameter C, and complies with the constraints within the range of 96MeVfm-3≲C≲130MeVfm-3. The largest mass can reach 2.25M⊙ at C≃96.54MeVfm-3 and ms0≃145MeV. For the quark stars composed of the quark matter in color-flavor locked (CFL) phase, we can obtain quite large maximum masses at a sufficiently high gap value, but the value of ms0 is very important in deciding the maximum mass of the CFL quark stars.