J/A+A/606/A114 FARGO_THORIN 1.0 hydrodynamic code (Chrenko+, 2017)
Eccentricity excitation and merging of planetary embryos heated by pebble
accretion.
Chrenko O., Broz M., Lambrechts M.
<Astron. Astrophys. 606, A114 (2017)>
=2017A&A...606A.114C 2017A&A...606A.114C (SIMBAD/NED BibCode)
ADC_Keywords: Models
Keywords: hydrodynamics - planets and satellites: formation -
planet-disk interactions - protoplanetary disks -
planets and satellites: gaseous planets
Abstract:
Planetary embryos can continue to grow by pebble accretion until they
become giant planet cores. Simultaneously, these embryos mutually
interact and also migrate due to torques arising from the
protoplanetary disk.
Our aim is to study how pebble accretion alters the orbital evolution
of embryos undergoing Type-I migration. In particular, we try to
determine whether or not the embryos establish resonant chains, and if
so, whether or not these chains are prone to instabilities. Further,
we investigate the possibility that giant planet cores form through
embryo merging which can be more rapid than pebble accretion alone.
For the first time, we perform self-consistent global-scale radiative
hydrodynamic simulations of a two-fluid protoplanetary disk consisting
of gas and pebbles, the latter being accreted by embedded embryos.
Accretion heating, along with other radiative processes, is accounted
for to correctly model the Type-I migration.
We track the evolution of four super-Earth-like embryos, initially
located in a region where the disk structure allows for a convergent
migration. Generally, embryo merging is facilitated by rapidly
increasing embryo masses and breaks the otherwise oligarchic growth.
Moreover, we find that the orbital eccentricity of each embryo is
considerably excited (~=0.03) due to the presence of an asymmetric
under-dense lobe of gas - a so-called "hot trail" - produced by
accretion heating of the embryo's vicinity. Eccentric orbits lead
the embryos to frequent close encounters and make resonant locking
more difficult.
Embryo merging typically produces one massive core (≥10ME) in our
simulations, orbiting near 10 AU. Pebble accretion is naturally
accompanied by the occurrence of eccentric orbits which should be
considered in future efforts to explain the structure of exoplanetary
systems.
Description:
This archive contains the source files, documentation and example
simulation setups of the FARGO_THORIN 1.0 hydrodynamic code. The
program was introduced, described and used for simulations in the
paper. It is built on top of the FARGO code (Masset,
2000A&AS..141..165M 2000A&AS..141..165M, Baruteau & Masset, 2008ApJ...672.1054B 2008ApJ...672.1054B) and it is
also interfaced with the REBOUND integrator package (Rein & Liu,
2012A&A...537A.128R 2012A&A...537A.128R). THORIN stands for Two-fluid HydrOdynamics, the
Rebound integrator Interface and Non-isothermal gas physics. The
program is designed for self-consistent investigations of
protoplanetary systems consisting of a gas disk, a disk of small solid
particles (pebbles) and embedded protoplanets.
Code features:
I) Non-isothermal gas disk with implicit numerical solution of the
energy equation. The implemented energy source terms are:
Compressional heating, viscous heating, stellar irradiation, vertical
escape of radiation, radiative diffusion in the midplane and radiative
feedback to accretion heating of protoplanets.
II) Planets evolved in 3D, with close encounters allowed. The orbits
are integrated using the IAS15 integrator (Rein & Spiegel,
2015MNRAS.446.1424R 2015MNRAS.446.1424R). The code detects the collisions among
planets and resolve them as mergers.
III) Refined treatment of the planet-disk gravitational interaction.
The code uses a vertical averaging of the gravitational potential,
as outlined in Muller & Kley (2012A&A...539A..18M 2012A&A...539A..18M).
IV) Pebble disk represented by an Eulerian, presureless and inviscid
fluid. The pebble dynamics is affected by the Epstein gas drag and
optionally by the diffusive effects. We also implemented the drag
back-reaction term into the Navier-Stokes equation for the gas.
Archive summary:
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directory/file Explanation
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/in_relax Contains setup of the first example simulation
/in_wplanet Contains setup of the second example simulation
/src_main Contains the source files of FARGO_THORIN
/src_reb Contains the source files of the REBOUND
integrator package to be linked with THORIN
GUNGPL3 GNU General Public License, version 3
LICENSE License agreement
README Simple user's guide
UserGuide.pdf Extended user's guide
refman.pdf Programer's guide
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fargo_thorin.tar 2383 56252 Tarball of the code
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Acknowledgements:
Ondej Chrenko, chrenko(at)sirrah.troja.mff.cuni.cz
(End) Patricia Vannier [CDS] 06-Jul-2017