  We present high angular resolution PdBI images (beam of ~0.33'') of the
J=27-26 line from several vibrational levels (v7=1 and v6=1) of HC3N toward
Cepheus A HW2. These images reveal the two main heating sources in the cluster:
one centered in the disk collimating the HW2 radio jet (the HW2 disk), and the
other associated with a hot core 0.3'' northeast HW2 (the HC). This is the
first time that vibrationally excited emission of HC3N is spatially resolved in
a disk. The kinematics of this emission shows that the HW2 disk rotates
following a Keplerian law. We derive the temperature profiles in the two
objects from the excitation of HC3N along the HW2 disk and the HC. These
profiles reveal that both objects are centrally heated and show temperature
gradients. The inner and hotter regions have temperatures of 350+-30K and
270+-20K for the HW2 disk and the HC, respectively. In the cooler and outer
regions, the temperature drops to 250+-30K in the HW2 disk, and to 220+-15K in
the HC. The estimated luminosity of the heating source of the HW2 disk is
~2.2E4Lo, and 3000Lo for the HC. The most massive protostar in the HW2 region
is the powering source of the HW2 radio jet. We discuss the formation of
multiple systems in this cluster. The proximity of the HC to HW2 suggest that
these sources likely form a binary system of B stars, explaining the observed
precession of the HW2 radio jet.
