Barbara Ercolano: "The Ionisation Structure of Planet Forming Discs and their Atmospheres"
Academic Year 2019/2020
Recent surveys have shown an overwhelming diversity of extrasolar planetary systems, prompting the question of how some may end up looking like our own and being able to sustain life. The environment in which planets form plays a major role in this issue. Planets are born out of the dust and gas left over whenever a new star forms: the protoplanetary disc (PPD). The initial conditions for planet formation are thus determined by the PPDs, which evolve and disperse as they give birth to planets.
The physical conditions in the PPD then strongly influence the processes of dust assembly believed to be behind the formation of rocky planetary embryos. The level of ionisation of the gas component of discs is of particular interest, as this determines the level of coupling of the planet forming material to magnetic fields that are believed to thread PPDs and drive accretion.
Latest research has shown that radiation from the central star, as well magnetic fields within the disc, may launch a wind, which influences the gas and dust density distribution and the chemical composition of PPDs and finally destroys it.
Barbara Ercolano’s CAS Research Group will build detailed photoionisation and thermal models of discs from their interior to their atmospheres and winds. The irradiation models will be for the first time linked to the evolution of dust particles in the disc as they assemble during the first stages of planet formation.