|
Special Colloquium |
Dr. Nienke van der Marel
| SCHEDULED |
Leiden University
Structures such as gaps and rings in ALMA observations of protoplanetary
disks have long been hailed as signposts of planet formation. However, a
direct link between exoplanets and protoplanetary disks remained hard to
identify. Recent work has shown that gapped disks retain high
millimeter-dust masses up to at least 10 Myr, whereas the majority of
disks is compact and decreases its dust mass rapidly. This can be
understood when considering dust evolution, where dust traps prevent
radial drift in the gapped disks. The fraction of gapped disks shows a
stellar mass dependence, and I propose a scenario linking this
dependence with that of giant exoplanet occurrence rates. It is shown
that there are enough exoplanets to account for the observed disk
structures if gapped disks are caused by exoplanets more massive than
Neptune, under the assumption that most of those planets eventually
migrate inwards. On the other hand, the known anti-correlation between
transiting super-Earths and stellar mass implies those planets must form
in the compact disks, consistent with those exoplanets forming through
pebble accretion in drift-dominated disks. I will demonstrate some of
the latest insights on rocky planet formation in compact disks, as well
as new insights on gas giant planet formation in larger gapped disks.
Finally, I will show that dust traps and radial drift may play a crucial
role in regulating the chemical composition of disks, which sets the C/O
ratio of exoplanet atmospheres as traced in the coming years with the
James Webb Space
Telescope.