Related papers: Disc fragmentation. I. Ejection of Jupiter-mass Fr…
Observations of massive stars within the central parsec of the Galaxy show that, while most stars orbit within a well-defined disc, a significant fraction have large eccentricities and / or inclinations with respect to the disc plane. Here,…
Planets are born from the gas and dust discs surrounding young stars. Energetic radiation from the central star can drive thermal outflows from the discs atmospheres, strongly affecting the evolution of the discs and the nascent planetary…
Upcoming studies of extrasolar gas giants will give precise insights into the composition of planetary atmospheres with the ultimate goal to link it to the formation history of the planet. Here, we investigate how drifting and evaporating…
A large fraction of the observed brown dwarfs may form by gravitational fragmentation of unstable discs. This model reproduces the brown dwarf desert, and provides an explanation the existence of planetary-mass objects and for the binary…
The migration of planets plays an important role in the early planet-formation process. An important problem has been that standard migration theories predict very rapid inward migration, which poses problems for population synthesis…
We investigate the formation and early evolution and fragmentation of an accretion disk around a forming massive protostar. We use a grid-based self-gravity-radiation-hydrodynamics code including a sub-grid module for stellar and dust…
Motivated by the recent discovery of massive planets on wide orbits, we present a mechanism for the formation of such planets via disk fragmentation in the embedded phase of star formation. In this phase, the forming disk intensively…
We study the three-dimensional evolution of a viscous protoplanetary disc which accretes gas material from a second protoplanetary disc during a close encounter in an embedded star cluster. The aim is to investigate the capability of the…
It is well known that massive protoplanetary disc are gravitationally unstable beyond tens of AU from their parent star. The eventual fate of the self-gravitating gas clumps born in the disc is currently not understood, although the range…
In recent years a correlation between mass accretion rates onto new-born stars and their proto-planetary disc masses was detected in nearby young star-forming regions. Although such a correlation can be interpreted as due to…
Circumplanetary discs (CPDs) form around young gas giants and are thought to be the sites of moon formation as well as an intermediate reservoir of gas that feeds the growth of the gas giant. How the physical properties of such CPDs are…
Due to the gas rich environments of early circumstellar disks, the gravitational collapse of cool, dense regions of the disk form fragments largely composed of gas. During formation, disk fragments may attain increased metallicities as they…
We argue that gravitational instability of typical protostellar disks is not a viable mechanism for the fragmentation into multiple systems -- binary stars, brown dwarf companions, or gas giant planets -- except at periods above roughly…
Giant planets dominate the mass of many planetary systems, including the Solar System, and represent the best-characterized class of extrasolar planets. Understanding the formation of giant planets bridges the high mass end of the planet…
We report the first characterisation of the individual discs in the intermediate separation binary systems KK Oph and HD 144668 at millimetre wavelengths. In both systems the circum-primary and the circum-secondary discs are detected in the…
The tidal perturbation of embedded protoplanets on their natal disks has been widely attributed to be the cause of gap-ring structures in sub-mm images of protoplanetary disks around T Tauri stars. Numerical simulations of this process have…
In this paper, we investigate how external photo-evaporation influences the formation, dynamical evolution and the resultant planetary architecture of multi-planet systems born in stellar clusters. We use a model of N-body simulations of…
Recent observations have shown the presence of extra-solar planets in Galactic open stellar clusters, as in the Praesepe (M44). These systems provide a favorable environment for planetary formation due to the high heavy-element content…
Warm giant planets with orbital periods of tens of days exhibit a positive correlation between mass and eccentricity. We interpret this trend as the outcome of planet-planet scattering, representing a transition from collision-dominated…
The origin of Jupiter-mass planets with orbital periods of only a few days is still uncertain. It is widely believed that these planets formed near the water-ice line of the protoplanetary disk, and subsequently migrated into much smaller…