Formation and properties of astrophysical carbonaceous dust

Abstract

The classical theory of grain nucleation suffers from both theoretical and predictive deficiencies. We strive to alleviate these deficiencies in our understanding of dust formation and growth by utilizing an atomistic model of nucleation. Carbon cluster geometries are determined with a set of global minimization algorithms. Using density functional theory, the binding energies of carbon clusters from $n=2$ to $n=99$ are then calculated. These energies are used to calculate the critical size and nucleation rate of carbon clusters. We find that the critical cluster size is largely determined by the changes in geometry of the clusters. Clusters with size $n=27$ and $n=8$, roughly corresponding to the transition from ring-to-fullerene geometry and chain-to-ring geometry respectively, are the critical sizes across the range of temperature and saturation where nucleation is significant. In contrast to the classical theory, nucleation is enhanced at low-temperatures, and suppressed at high temperatures. These results will be applied to a modified chemical evolution code using results from supernova simulations.

13 pages, 7 figures. Proceedings of Cosmic Dust VIII conference in Tokyo, 2015

References in corpus (7)

• A stubbornly large mass of cold dust in the ejecta of Supernova 1987A
• Thermal Emission from Warm Dust in the Most Distant Quasars
• Condensation of dust in the ejecta of type II-P supernovae
• The timing and location of dust formation in the remnant of SN 1987A
• The Chemistry of Population III Supernova Ejecta: I - Formation of Molecules in the Early Universe
• Formation and properties of astrophysical carbonaceous dust. I: ab-initio calculations of the configuration and binding energies of small carbon clusters
• The nature of HHL 73 from optical imaging and Integral Field Spectroscopy

Cited by in corpus (1)

• Cosmic dust VIII