Thermal and Photophoretic Properties of Dust Mantled Chondrules and Sorting in the Solar Nebula

Abstract

Many chondrules are found to be surrounded by a fine grained rim. Supposedly, these rims were acquired from dust accreted to the chondrules in a protoplanetary disk. In numerical simulations we study the heat transfer in illuminated bare and dust mantled chondrules. The calculations consider the chondrule size, the dust mantle size, and the thermal conductivities of both components as parameters. We calculate the photophoretic force and compare the numerical results to analytical approximations. We give an expression to quantify the photophoretic force on a spherical particle in the free molecular regime to better than 2%. We describe the influence of a dust mantle on the photophoretic strength by an effective thermal conductivity of the core-mantle particle. The effective thermal conductivity significantly depends on the size ratio between mantle and chondrule but not on the absolute sizes. It also strongly depends on the thermal conductivity of the mantle with minor influence of the thermal conductivity of the chondrule. The size ratio between rim and chondrule in meteorites is found to vary systematically with overall size by other authors. Based on this, our calculations show that a photophoretic size sorting can occur for dust mantled chondrules in optically thin disks or at the evolving inner edge of the solar nebula.

10 pages

References in corpus (7)

• Very Low-Mass Objects in the Coronet Cluster: The Realm of the Transition Disks
• Co-Accretion of Chondrules and Dust in the Solar Nebula
• The photophoretic sweeping of dust in transient protoplanetary disks
• Experiments on the Photophoretic Motion of Chondrules and Dust Aggregates - Indications for the Transport of Matter in Protoplanetary Disks
• Effects of photophoresis on the evolution of transitional circumstellar disks
• Photophoretic Structuring of Circumstellar Dust Disks
• Accretion of dust by chondrules in a MHD-turbulent solar nebula

Cited by in corpus (12)

• Photophoretic separation of metals and silicates: the formation of Mercury like planets and metal depletion in chondrites
• Experiments on centimeter-sized dust aggregates and their implications for planetesimal formation
• Effects of photophoresis on the dust distribution in a 3D protoplanetary disc
• Thermal conductivity and coordination number of compressed dust aggregates
• Photophoresis on particles hotter/colder than the ambient gas in the free molecular flow
• Photophoretic Strength on Chondrules. 2. Experiment
• Photophoretic Strength on Chondrules 1: Modeling
• Selective Aggregation Experiments on Planetesimal Formation and Mercury-Like Planets
• The motion of chondrules and other particles in a protoplanetary disc with temperature fluctuations
• Photophoresis in the circumjovian disk and its impact on the orbital configuration of the Galilean satellites
• Photophoretic Levitation and Trapping of Dust in the Inner Regions of Protoplanetary Disks
• Accretion through the inner edges of protoplanetary disks by a giant solid state pump