2019-02-27, 15:00: Dr. Lucia Klarmann (Max Planck Institute for Astronomy, Germany)
Dr. Lucia Klarmann
Max Planck Institute for Astronomy, Germany
The base material of terrestrial planets – investigating the dust in the inner region of protoplanetary disks
The inner regions of protoplanetary disks are where terrestrial planets and super-Earths form and/or migrate to. The small spatial extent of this region makes direct observations difficult. But interferometric observations and dust modelling can put constraints on the base material of terrestrial planet formation.
Motivated by the low carbon fraction in the Earth, we investigate how to sustain a low fraction of refractory carbon in the inner disk. We find that radial dust transport in the disk must be significantly reduced during parent body formation, possibly by a quickly formed giant planet core. Otherwise, grains from the outer disk region will replenish refractory carbon very efficiently within the grain drift timescale.
To constrain the inner rim composition with NIR interferometry, we self-consistently calculate the expected rim structure for a wide range of possible dust compositions. Synthetic observations of these radiative transfer models show that the rim position can be well constrained using NIR interferometry. Comparing our rim positions with observations from Lazareff+17, we find that the observed positions can be explained by a power law grain size distribution, but also the presence of highly refractory grains. We also propose the presence of very small carbonaceous grains disks with extended NIR flux.
Location: 31 Fitzwilliam Place