WInDI: a Warp-Induced Dust Instability in protoplanetary discs

We identify a new dust instability that occurs in warped discs. The instability is caused by the oscillatory gas motions induced by the warp in the bending wave regime. We first demonstrate the instability using a local 1D (vertical) toy model based on the warped shearing box coordinates and investigate the effects of the warp magnitude and...

The role of drag and gravity on dust concentration in a gravitationally unstable disc

We carry out three-dimensional smoothed particle hydrodynamics simulations to study the role of gravitational and drag forces on the concentration of large dust grains (St > 1) in the spiral arms of gravitationally unstable protoplanetary discs, and the resulting implications for planet formation. We find that both drag and gravity play an...

Collision detection for N-body Kepler systems

Context. In a Keplerian system, a large number of bodies orbit a central mass. Accretion disks, protoplanetary disks, asteroid belts, and planetary rings are examples. Simulations of these systems require algorithms that are computationally efficient. The inclusion of collisions in the simulations is challenging but important. Aims. We intend...

Observing circumplanetary disks with METIS

Context. Gaining a full understanding of the planet and moon formation process calls for observations that probe the circumplanetary environment of accreting giant planets. The mid-infrared ELT imager and spectrograph (METIS) will provide a unique capability to detect warm-gas emission lines from circumplanetary disks. Aims. We aim to...

Circumplanetary disk ices: II. Composition

Context. The subsurface oceans of icy satellites are among the most compelling among the potentially habitable environments in our Solar System. The question of whether a liquid subsurface layer can be maintained over geological timescales depends on its chemical composition. The composition of icy satellites is linked to that of the...

Efficiency of an analytical propagator with collision detection for Keplerian systems

The aim of this thesis was to test the efficiency in practice of an analytical propagator with collision detection for <i>N</i>-body Keplerian systems. This can be used to simulate the evolution of a protoplanetary disk, which gives insight into how planetary systems form. The analytic propagator calculates collisions one by one, while a...

Erratum: Ices in planet-forming disks: Self-consistent ice opacities in disk models (A&A (2017) 600 DOI: 10.1051/0004-6361/201629711)

Context. In cold and shielded environments, molecules freeze out on dust grain surfaces to form ices such as H2O, CO, CO2, CH4, CH3OH, and NH3. In protoplanetary disks, such conditions are present in the midplane regions beyond the snowline, but the exact radial and vertical extension depend on disk mass, geometry, and stellar ultra-violet...

Circumplanetary disk ices: I. Ice formation vs. viscous evolution and grain drift

Context. The large icy moons of Jupiter formed in a circumplanetary disk (CPD). CPDs are fed by vertically infalling circumstellar gas and dust which may be shock-heated upon accretion. Accreted material is then either incorporated into moons, falls into the planet, or is lost beyond the disk edge on relatively short timescales. If ices are...

Optical appearance of ices in planet forming discs

This thesis aims to improve our understanding of the role of ices in planet forming discs, known as protoplanetary discs. Computer models of such discs have been used extensively by the community to understand and predict the observational data. It has always been a challenge to observe ices in the discs and their optical appearance is largely...

Polarimetric imaging mode of VLT/SPHERE/IRDIS: I. Description, data reduction, and observing strategy

Context. Polarimetric imaging is one of the most effective techniques for high-contrast imaging and for the characterization of protoplanetary disks, and it has the potential of becoming instrumental in the characterization of exoplanets. The Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument installed on the Very Large...

Gas Giants from a Protoplanetary Disk: Thesis report

The Earth is not the only planet in the universe. It has been known for millennia that there are other planets and other bodies in the solar system. Moreover, as recent as, 1995 it has been confirmed that other stars also host planets. But how did they form? This is the main question that planet formation research has been trying to answer for...