相关论文: Dust concentration and chondrule formation

Coarse objects in chondrites such as chondrules and CAIs are mostly coated with fine-grained rims (FGRs). FGRs can be formed on the surface of free floating chondrules in a turbulent nebula, where dust aggregation also occurs. A former…

We investigate the condition for the formation of low-mass second-generation stars in the early universe. It has been proposed that gas cooling by dust thermal emission can trigger fragmentation of a low-metallicity star-forming gas cloud.…

Even today in our Galaxy, stars form from gas cores in a variety of environments, which may affect the properties of resulting star and planetary systems. Here we study the role of pressure, parameterized via ambient clump mass surface…

Clouds seem like an every-day experience. But -- do we know how clouds form on brown dwarfs and extra-solar planets? How do they look like? Can we see them? What are they composed of? Cloud formation is an old-fashioned but still…

Dust coagulation in interstellar space and protoplanetary disks is usually treated as one of 2 extreme cases: Particle-Cluster Aggregation and Cluster-Cluster Aggregation. In this paper we study the process of hierarchical growth, where…

We propose the possibility of a new phenomenon affecting the settling of dust grains at the terrestrial region in early protoplanetary disks. Sinking dust grains evaporate in a hot inner region during the early stage of disk evolution, and…

Organic macromolecular matter is the dominant carrier of volatile elements such as carbon, nitrogen, and noble gases in chondrites -- the rocky building blocks from which Earth formed. How this macromolecular substance formed in space is…

Two basic routes for planetesimal formation have been proposed over the last few decades. One is a classical "slow-growth" scenario. Another one is particle concentration models, in which small pebbles are concentrated locally and then…

The bulk volatile contents of chondritic meteorites provide clues to their origins. Matrix and chondrules carry differing abundances of moderately volatile elements, with chondrules carrying a refractory signature. At the high temperatures…

In order to characterize the early growth of fine-grained dust rims (FGRs) that commonly surround chondrules, we simulate the growth of FGRs through direct accretion of monomers of various sizes onto the chondrule surfaces. Dust becomes…

The formation of planetary cores must proceed rapidly in order for the giant planets to accrete their gaseous envelopes before the dissipation of the protoplanetary gas disc (<3 Myr). In orbits beyond 10 AU, direct accumulation of…

Millimeter astronomy provides valuable information on the birthplaces of planetary systems. In order to compare theoretical models with observations, the dust component has to be carefully calculated. Here, we aim to study the effects of…

How starburst clusters form out of molecular clouds is still an open question. In this article, I highlight some of the key constraints in this regard, that one can get from the dynamical evolutionary properties of dense stellar systems. I…

The past decade has seen major progress in our understanding of terrestrial planet formation. Yet key questions remain. In this review we first address the growth of 100 km-scale planetesimals as a consequence of dust coagulation and…

The realization that most stars form in clusters, raises the question of whether star/planet formation are influenced by the cluster environment. The stellar density in the most prevalent clusters is the key factor here. Whether dominant…

The early stages of planet formation are still not well understood. Coagulation models have revealed numerous obstacles to the dust growth, such as the bouncing, fragmentation and radial drift barriers. We study the interplay between dust…

Our understanding of the process of terrestrial planet formation has grown markedly over the past 20 years, yet key questions remain. This review begins by first addressing the critical, earliest stage of dust coagulation and concentration.…

Understanding the collisional behavior of dust aggregates is essential in the context of planet formation. It is known that low-velocity collisions of dust aggregates result in bouncing rather than sticking when the filling factor of…

Wolf-Rayet (WR) stars are the evolutionary phases of very massive stars prior to the final supernova explosion stage. These stars lose substantial mass during WN and WC stages. The mass losses are associated with diverse elemental and…

We present a new instability driven by a combination of coagulation and radial drift of dust particles. We refer to this instability as ``coagulation instability" and regard it as a promising mechanism to concentrate dust particles and…