Among multi-planet planetary systems there are a large fraction of resonant
systems. Studying the dynamics and formation of these systems can provide
valuable informations on processes taking place in protoplanetary disks where
the planets are thought have been formed. The recently discovered resonant
system HD 60532 is the only confirmed case, in which the central star hosts a
pair of giant planets in 3:1 mean motion resonance. We intend to provide a
physical scenario for the formation of HD 60532, which is consistent with the
orbital solutions derived from the radial velocity measurements. Observations
indicate that the system is in an antisymmetric configuration, while previous
theoretical investigations indicate an asymmetric equilibrium state. The paper
aims at answering this discrepancy as well. We performed two-dimensional
hydrodynamical simulations of thin disks with an embedded pair of massive
planets. Additionally, migration and resonant capture are studied by
gravitational N-body simulations that apply properly parametrized
non-conservative forces. Our simulations suggest that the capture into the 3:1
mean motion resonance takes place only for higher planetary masses, thus
favouring orbital solutions having relatively smaller inclination i=20 degrees.
The system formed by numerical simulations qualitatively show the same
behaviour as HD 60532. We also find that the presence of an inner disk (between
the inner planet and the star) plays a very important role in determining the
final configurations of resonant planetary systems. Its damping effect on the
inner planet's eccentricity is responsible for the observed antisymmetric state
of HD 60532.Comment: 7 pages, 7 figures, Accepted for publication in Astronomy &
Astrophysic