Related papers: Explaining millimeter-sized particles in brown dwa…
We aim at understanding the formation of cloud layers in quasi-static substellar atmospheres. The time-dependent description presented in (Helling & Woitke 2006) is a kinetic model describing nucleation, growth and evaporation. It is…
Context: The global size and spatial distribution of dust is an important ingredient in the structure and evolution of protoplanetary disks and in the formation of larger bodies, such as planetesimals. Aims: We aim to derive simple…
The recently discovered exoplanets in binary or higher-order multiple stellar systems sparked a new interest in the study of proto-planetary discs in stellar aggregations. Here we focus on disc solids, as they make up the reservoir out of…
Characterizing the physical properties of dust grains in a protoplanetary disk is critical to comprehending the planet formation process. Our study presents ALMA high-resolution observations of the young protoplanetary disk around DG Tau at…
This paper is one in a series presenting results obtained within the Formation and Evolution of Planetary Systems (FEPS) Legacy Science Program on the Spitzer Space Telescope. Here we present a study of dust processing and growth in seven…
Aims: In order to understand the first stages of planet formation, when tiny grains aggregate to form planetesimals, one needs to simultaneously model grain growth, vertical settling and radial migration of dust in protoplanetary disks. In…
Aims: Grain growth has been suggested as one possible explanation for the diminished dust optical depths in the inner regions of protoplanetary "transition" disks. In this work, we directly test this hypothesis in the context of current…
Observations of protoplanetary disks provide information on planet formation and the reasons for the diversity of planetary systems. The key to understanding planet formation is the study of dust evolution from small grains to pebbles.…
Our first aim is to calculate the minimum mass for Primary Fragmentation in a variety of potential star-formation scenarios, i.e. (i) hierarchical fragmentation of a 3-D medium; (ii) one-shot, 2-D fragmentation of a shock-compressed layer;…
We present the largest sample of brown dwarf (BD) protoplanetary disk spectral energy distributions modeled to date. We compile 49 objects with ALMA observations from four star-forming regions: $\rho$ Ophiuchus, Taurus, Lupus, and Upper…
We review the properties of dust in protoplanetary disks around optically visible pre-main sequence stars obtained with a variety of observational techniques, from measurements of scattered light at visual and infrared wavelengths to…
We discovered a new growth mode of dust grains to km-sized bodies in protoplanetary disks that evolve by viscous accretion and magnetically driven disk winds (MDWs). We solved an approximate coagulation equation of dust grains with…
We critically examine the best lines of evidence for grain growth in protoplanetary disks, based on modelling of observed spectral energy distributions and images of T Tauri and Herbig Ae stars. The data are consistent with millimeter-sized…
We investigate dust dynamics and evolution during the formation of a protostellar accretion disk around intermediate mass stars via 2D numerical simulations. Using three different detailed dust models, compact spherical particles, fractal…
Disks around very low-mass stars (VLMS) provide environments for the formation of Earth-like planets. Mid-infrared observations have revealed that these disks exhibit weak silicate features and strong hydrocarbon emissions. This study…
Context: We studied numerically the formation of giant planet (GP) and brown dwarf (BD) embryos in gravitationally unstable protostellar disks and compared our findings with directly-imaged, wide-orbit (>= 50 AU) companions known to-date.…
We report the complete photometric results from our Herschel study which is the first comprehensive program to search for far-infrared emission from cold dust around young brown dwarfs. We surveyed 50 fields containing 51 known or suspected…
Context: The principal mechanism by which brown dwarfs form, and its relation to the formation of higher-mass (i.e. hydrogen-burning) stars, is poorly understood. Aims: We advocate a new model for the formation of brown dwarfs. Methods: In…
Most stars are born in clusters and the resulting gravitational interactions between cluster members may significantly affect the evolution of circumstellar discs and therefore the formation of planets and brown dwarfs. Recent findings…
Mid-infrared spectra of 65 T Tauri stars (TTS) taken with the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope are modeled using dust at two temperatures to probe the radial variation in dust composition in the uppermost…