In an effort led by senior team-member Ch. Brinch, we have obtained Atacama Large (sub-)Millimeter Array (ALMA) data of the binary protostars IRS-43. The ALMA data in the sub-mm band has been thoroughly analysed with respect to the highly unusual mutual misalignment of the circumbinary disk with the two circumstellar disks. The case study resulted in a high-profile publication in Astrophysical Journal Letters (Brinch et al. 2016, ApJ Letters), with widely received press-releases, spawned in media outlets across the globe (among others: Nature news, Sky & Telescope, New Scientist, Popular Mechanics, IFL Science, space.com as well as roughly one hundred independent newspapers around the globe).
Imaging of dust continuum emitted from disks around nearby protostars reveals diverse substructure. Turbulence in the realm of non-ideal magnetohydrodynamics is one candidate for explaining the generation of zonal flows which can lead to local dust enhancements. In our effort, we consider combinations of vertical and azimuthal initial net flux and perform 3D non-ideal MHD simulations aimed at studying self-organization induced by the Hall effect in turbulent disks. We include dust grains, treated in the fluid approximation, in order to study their evolution subject to the emerging zonal flows. In the regime of a dominant Hall effect, we robustly obtain large-scale organized concentrations in the vertical field that remain stable for many orbits (Krapp et al. 2018, ApJ). Our research has, moreover, found that including a moderately strong net-azimuthal magnetic flux can significantly alter the dynamics, partially preventing the self-organization of zonal flows.
Outflows driven by large-scale magnetic fields likely play an important role in the evolution and dispersal of protoplanetary disks, and in setting the conditions for planet formation. We extend our 2D axisymmetric non-ideal MHD model of these outflows by incorporating radiative transfer and simplified thermochemistry, with the twin aims of exploring how heating influences wind launching, and illustrating how such models can be tested through observations of diagnostic spectral lines. Our model disks launch magnetocentrifugal outflows primarily through magnetic tension forces, so the mass-loss rate increases only moderately when thermochemical effects are switched on. For typical field strengths, thermochemical and irradiation heating are more important than magnetic dissipation. We furthermore find that the entrained vertical magnetic flux diffuses out of the disk on secular timescales as a result of non-ideal MHD. Through post-processing line radiative transfer, we demonstrate that spectral line intensities and moment-1 maps of atomic oxygen, the HCN molecule, and other species show potentially observable differences between a model with a magnetically driven outflow and one with a weaker, photoevaporative outflow (Gressel et al. 2020, ApJ).
