Related papers: Turbulence and its effect on protostellar disk for…
A fundamental assumption in our understanding of disks is that when the Toomre Q>>1, the disk is stable against fragmentation into self-gravitating objects (and so cannot form planets via direct collapse). But if disks are turbulent, this…
Gravitational instability (GI) features in several aspects of protostellar disk evolution, most notably in angular momentum transport, fragmentation, and the outbursts exemplified by FU Ori and EX Lupi systems. The outer regions of…
We characterize magnetically driven accretion at radii between 1 au and 100 au in protoplanetary discs, using a series of local non-ideal magnetohydrodynamic (MHD) simulations. The simulations assume a Minimum Mass Solar Nebula (MMSN) disc…
Efficient magnetic braking is a formidable obstacle to the formation of rotationally supported disks (RSDs) around protostars in magnetized dense cores. We have previously shown, through 2D (axisymmetric) non-ideal MHD simulations, that…
We address the formation of giant clumps in violently unstable gas-rich disc galaxies at cosmic noon. While these are commonly thought to originate from gravitational Toomre instability, cosmological simulations have indicated that clumps…
We present basic properties of protostellar disks in the embedded phase of star formation (EPSF), which is difficult to probe observationally using available observational facilities. We use numerical hydrodynamics simulations of cloud core…
It is established that the formation of rotationally supported disks during the main accretion phase of star formation is suppressed by a moderately strong magnetic field in the ideal MHD limit. Non-ideal MHD effects are expected to weaken…
The magnetic fields associated with young stellar objects are expected to have an hour-glass geometry, i.e., the magnetic field lines are pinched as they thread the equatorial plane surrounding the forming star but merge smoothly onto a…
Improving our understanding of the earliest stages of star formation is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. We discuss recent advances made in this area thanks to detailed…
We explore the effect of magnetorotational turbulence on the dynamics and concentrations of boulders in local box simulations of a sub-Keplerian protoplanetary disc. The solids are treated as particles each with an independent space…
Protoplanetary discs are made of gas and dust orbiting a young star. They are also the birth place of planetary systems, which motivates a large amount of observational and theoretical research. In these lecture notes, I present a review of…
(Abridged) We present a series of decaying turbulence simulations that represent a cluster-forming clump within a molecular cloud, investigating the role of magnetic fields on the formation of potential star-forming cores. We present an…
We have carried out hydro-dynamical simulations to investigate the formation and evolution of protostar and circumstellar disks from the prestellar cloud. As the initial state, we adopt the molecular cloud core with two non-dimensional…
We investigate the impact of different initial conditions for the initial density profile and the initial turbulence on the formation process of protostellar clusters. We study the collapse of dense molecula r cloud cores with…
We describe the results of a sequence of simulations of gravitational collapse in a turbulent magnetized region. The parameters are chosen to be representative of molecular cloud material. We find that several protostellar cores and…
We present a new perspective on the crystallinity of dust in protoplanetary disks. The dominant crystallization by thermal annealing happens in the very early phases of disk formation and evolution. Both the disk properties and the level of…
Protostellar disks are the product of angular momentum conservation during the protostellar collapse. Understanding their formation is crucial because they are the birthplace of planets and because their formation is tightly related to star…
We present the results of a series of numerical simulations of compressible, self-gravitating hydrodynamic turbulence of cluster-forming clumps in molecular clouds. We examine the role that turbulence has in the formation of gravitationally…
Turbulent viscosity in cold accretion disks is likely to be hydrodynamic in origin. We investigate the growth of hydrodynamic perturbations in a small region of a disk, which we model as a linear shear flow with Coriolis force, between two…
We present results from the first three-dimensional radiation hydrodynamical calculations to follow the collapse of a molecular cloud core beyond the formation of the stellar core. We find the energy released by the formation of the stellar…