Accurate sticking coefficient calculation for carbonaceous dust growth through accretion and desorption in astrophysical environments

Abstract

Context. Cosmic dust is ubiquitous in astrophysical environments, where it significantly influences the chemistry and the spectra. Dust grains are likely to grow through the accretion of atoms and molecules from the gas-phase onto them. Despite their importance, only a few studies compute sticking coefficients for relevant temperatures and species, and their direct impact on grain growth. Overall, the formation of dust and its growth are processes not well understood. Aims. To calculate sticking coefficients, binding energies, and grain growth rates over a wide range of temperatures, for various gas species interacting with carbonaceous dust grains. Methods. We perform molecular dynamics simulations with a reactive force field algorithm to compute accurate sticking coefficients and obtain binding energies. The results are included in an astrophysical model of nucleation regions to study dust growth. Results. We present, for the first time, sticking coefficients of H, H2, C, O, and CO on amorphous carbon structures for temperatures ranging from 50 K to 2250 K. In addition, we estimate the binding energies of H, C, and O in carbonaceous dust to calculate the thermal desorption rates. Combining accretion and desorption allows us to determine an effective accretion rate and sublimation temperature for carbonaceous dust. Conclusions. We find that sticking coefficients can differ substantially from what is commonly used in astrophysical models and this gives new insight on carbonaceous dust grain growth via accretion in dust-forming regions.

Accepted for publication in Astronomy & Astrophysics (A&A)

References in corpus (13)

• Machine-learning based interatomic potential for amorphous carbon
• The Origin of Dust in the Early Universe: Probing the Star Formation History of Galaxies by their Dust Content
• The C/O ratio at low metallicity: constraints on early chemical evolution from observations of Galactic halo stars
• Dust growth in the interstellar medium: How do accretion and coagulation interplay?
• Effects of grain size distribution on the interstellar dust mass growth
• Sticking coefficient of hydrogen and deuterium on silicates under interstellar conditions
• The mass-loss, expansion velocities and dust production rates of carbon stars in the Magellanic Clouds
• Temperature programed desorption of water ice from the surface of amorphous carbon and silicate grains as related to planet-forming disks
• When sticking influences H2 formation
• Dust Formation in Astrophysical Environments: The Importance of Kinetics
• Understanding the evolution and dust formation of carbon stars in the LMC with a look at the JWST
• Formation, distribution, and IR emission of dust in the clumpy ejecta of Type II-P core-collapse supernovae, in isotropic and anisotropic scenarios
• Laboratory-based sticking coefficients for ices on a variety of small grains analogs

Cited by in corpus (4)

• Ashes of FIRE: Modeling Dust Grain Size Evolution in the Local Group with FIRE
• The essential elements of dust evolution: a-C(:H) nanoparticle sub-structures and photo-fragmentation
• The Binding Energies of Atoms on Amorphous Silicate Dust: A Computational Study
• The cosmic journey of dust grains -- from nucleation to planetary system