Circum-planetary accretion disks

• Applicant: Professor Dr. Wilhelm Kley (†)
• Subject Area: Astrophysics and Astronomy
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 29735732

• Final Report Year: 2010

Final Report Abstract

In the project we have addressed several important problems in the theory of planet formation. Main focus of the project has been on the interaction of a young growing planet with its ambient disk. For single small mass planets we could show that the inclusion of the correct thermodynamics of the disk can change dramatically the migration properties of the planets from inward to outward. This finding may help to resolve the outstanding problem of too rapid inward type I migration of embedded planets. In a related work we concentrated on the circumplanetary disk (CPD) around young planets that forms inside the Hill sphere. We performed very high resolution simulations to estimate structure and dynamical influence of the CPD on planetary migration. As in many planetdisk simulations the treatment of material in the Hill sphere is only very crude and rudimentary we performed a detailed analysis of all forces and compared different treatments to the fully selfgravitating case. The treatment of both above projects have been 2-dimensional and the natural extension would be fiill 3D simulations. For the first case (radiative disks) this has been achieved partially, while for the latter case the resolution requirements are still tremendous and the effect of self-gravity is also difficult in 3D. In two additional projects the evolution of a system of planets has been analyzed. In the first project we focussed on the eccentricity evolution of resonant planetary systems, and we could show that the damping effect of an inner disk around the star can resolve the outstanding problem of the observed small values of the eccentricities in observed resonant planetary systems. In a related study we could show that the migration behaviour of the 4 gaseous planets in the early solar nebula indicate that the density profile ofthe standard Minimum Mass Solar Nebula (MMSN) gives better agreement with the observations than the recentiy suggested much steeper profile by Desch (2007).

Publications

• 2008, American Astronomical Society, DPS meeting 40, Bulletin of the American Astronomical Society, Vol. 40, p.504, "Planetary Migration in non-isothermal disks"
  Crida, A., Kley, W.
  
• 2008, Astron. Astrophys, 483, 325 "Influence of an inner disc on the orbital evolution of massive planets migrating in resonance"
  Crida, A., Sandor. Z. & Kley W.
  
• 2008, Astron. Astrophys, 487, L9 "Migration of protoplanets in radiative discs"
  Kley W. & Crida, A.
  
• 2009, Astron. Astrophys, 502, 679 "The dynamical role of the circumplanetary disc in planetary migration"
  Crida, A., Baruteau, C, Kley, W. & Masset, F.
  
• 2009, Astrophysical Journal 698, 606 "Minimum mass solar nebulae and planetary migration"
  Crida, A.
  
• 2009, on Solar System formation, at the JENAM 2008 conference. Reviews in Modem Astronomy, 21, "Solar System formation"
  Crida, A.
  
• 2009, Proceedings ofthe Annual meeting ofthe French Society of Astronomy and Astrophysics, 2009, Eds. E. Heydari-Malayeri, C. Reyle and R. Samadi, "Minimum mass solar nebulae and planetary migration"
  Crida, A.
  
• 2010, EAS Publications Series, 41, 387 "Planetary migration in resonance : the question of the eccentricities"
  Crida, A., Sandor, Z. & Kley W.