Formation of massive gas giants on wide orbits

Abstract

We present a mechanism for the formation of massive gas giants on wide orbits via disk fragmentation in the embedded phase of star formation. In this phase, protostellar disks undergo radial pulsations which lead to periodic disk compressions and formation of massive fragments on radial distances of the order of 50-300 AU. The fragments that form during the last episode of disk compression near the end of the embedded phase, when torque from spiral arms become weaker, may survive and mature into massive gas giants. This phenomenon can explain the existence of massive exoplanets on wide orbits is such systems as Fomalhaut and HR 8799. © International Astronomical Union 2011.