  A commonly applied quark matter model in astrophysics is the thermodynamic
bag model (tdBAG). The original MIT bag model approximates the effect of quark
confinement, but does not explicitly account for the breaking of chiral
symmetry, an important property of Quantum Chromodynamics (QCD). It further
ignores vector repulsion. The vector-interaction-enhanced bag model (vBag)
improves the tdBAG approach by accounting for both dynamical chiral symmetry
breaking and repulsive vector interactions. The latter is of particular
importance to studies of dense matter in beta-equilibriumto explain the two
solar mass maximum mass constraint for neutron stars. The model is motivated by
analyses of QCD based Dyson-Schwinger equations (DSE), assuming a simple
quark-quark contact interaction. Here, we focus on the study of hybrid neutron
star properties resulting from the application of vBag and will discuss
possible extensions.
