  The precise measurement of the high masses of the pulsars PSR J1614-2230
(M_{1614}=1.97 +- 0.04 solar masses) and PSR J0348-0432 (M_{0348}=2.01 +- 0.04
solar masses) provides an important constraint for the equation of state of
cold, dense matter and is suited to give interesting insights regarding the
nature and existence of the possible phase transition to deconfined quark
matter in the cores of neutron stars. We analyze the stability and composition
of compact star sequences for a class of hybrid nuclear - quark-matter
equations of state. The quark matter phase is described in the framework of a
standard color superconducting 3-flavor Nambu-Jona-Lasinio model and the
hadronic phase is given by the Dirac-Brueckner-Hartree-Fock equation of state
for the Bonn-A potential. The phase transition is obtained by a Maxwell
construction. Within this model setup we aim to constrain otherwise not
strictly fixed parameters of the NJL model, namely the coupling strengths in
the vector meson and diquark interaction channels. We perform this
investigation for two different parameterizations characterized by a different
scalar coupling constant. The analysis of flow data obtained in heavy-ion
collisions resulted in a further constraint which we account for in our
discussion. Massive hybrid stars with extended quark matter cores can be
obtained in accordance with all of the considered constraints.
