INVESTIGADORES
BRUNINI Adrian
artículos
Título:
Simultaneous formation of solar system giant planets
Autor/es:
GUILERA, O. M.; FORTIER, A.; BRUNINI, A.; BENVENUTO, O. G.
Revista:
ASTRONOMY AND ASTROPHYSICS
Editorial:
EDP SCIENCES S A
Referencias:
Lugar: Paris; Año: 2011 vol. 532 p. 142 - 150
ISSN:
0004-6361
Resumen:
Context. In the last few years, the so-called "Nice model" has become
increasingly significant for studying the formation and evolution of the
solar system. According to this model, the initial orbital configuration
of the giant planets was much more compact than the one we observe
today. <BR /> Aims: We study the formation of the giant planets in
connection with several parameters that describe the protoplanetary
disk. We aim to establish which conditions enable their simultaneous
formation in line with the initial configuration proposed by the Nice
model. We focus on the conditions that lead to the simultaneous
formation of two massive cores, corresponding to Jupiter and Saturn,
which are able to reach the cross-over mass (where the mass of the
envelope of the giant planet equals the mass of the core, and gaseous
runway starts), while two other cores that correspond to Uranus and
Neptune have to be able to grow to their current masses. <BR /> Methods:
We compute the in situ planetary formation, employing the numerical code
introduced in our previous work for different density profiles of the
protoplanetary disk. Planetesimal migration is taken into account and
planetesimals are considered to follow a size distribution between
r_p<SUP>min</SUP> (free parameter) and r_p<SUP>max= 100</SUP> km. The
core´s growth is computed according to the oligarchic growth regime. <BR
/> Results: The simultaneous formation of the giant planets was
successfully completed for several initial conditions of the disk. We
find that for protoplanetary disks characterized by a power law (?
? r<SUP> - p</SUP>), flat surface density profiles (p ? 1.5)
favor the simultaneous formation. However, for steep slopes (p 2, as
previously proposed by other authors) the simultaneous formation of the
solar system giant planets is unlikely. <BR /> Conclusions: The
simultaneous formation of the giant planets - in the context of the Nice
model - is favored by flat surface density profiles. The formation
time-scale agrees with the estimates of disk lifetimes if a significant
mass of the solids accreted by the planets is contained in planetesimals
with radii < 1 km.