The interaction between a gaseous protostellar disc and the embedded planetesimals through a drag force generally causes the latter to migrate inwards, the migration rate being very rapid (of the order of 103 yrs) for metre-size objects. Here we show how, in the presence of a spiral structure caused by the disc self-gravity, the drag force has the effect of concentrating significantly the planetesimals around the peaks of the gas density. Metre-size particles, in this configuration, can enhance their concentration by more than two orders of magnitude, therefore significantly accelerating their growth and the formation of the cores of giant planets.
|Title of host publication||Memorie della Società Astronomica Italiana|
|Publication status||Published - 2005|
- accretion discs
- stars: pre-main-sequence
- planetary systems: formation planetary systems: protoplanetary discs