Evolving grain-size distributions embedded in gas flows
| Autor: | S. Van Loo, R Sumpter |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
COLLISIONS
SIO EMISSION Discretization COAGULATION FOS: Physical sciences 01 natural sciences Bin RATIO Approximation error 0103 physical sciences 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) DESTRUCTION Cosmic dust Earth and Planetary Astrophysics (astro-ph.EP) Physics 010308 nuclear & particles physics numerical [methods] Astronomy and Astrophysics plasmas Astrophysics - Astrophysics of Galaxies Grain size Computational physics DENSE CLOUDS SHOCK-WAVES Distribution function Distribution (mathematics) Astrophysics - Solar and Stellar Astrophysics Physics and Astronomy Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) hydrodynamics MOLECULAR CLOUDS dust FRAGMENTATION Constant (mathematics) INTERSTELLAR DUST Astrophysics - Earth and Planetary Astrophysics |
| Zdroj: | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/staa846 |
| Popis: | We present a numerical approach for accurately evolving a dust grain-size distribution undergoing number-conserving (such as sputtering) and/or mass-conserving (such as shattering) processes. As typically observed interstellar dust distributions follow a power-law, our method adopts a power-law discretisation and uses both the grain mass and number densities in each bin to determine the power-law parameters. This power-law method is complementary to piecewise-constant and linear methods in the literature. We find that the power-law method surpasses the other two approaches, especially for small bin numbers. In the sputtering tests the relative error in the total grain mass remains below 0.01% independent of the number of bins N, while the other methods only achieve this for N > 50 or higher. Likewise, the shattering test shows that the method also produces small relative errors in the total grain numbers while conserving mass. Not only does the power-law method conserve the global distribution properties, it also preserves the inter-bin characteristics so that the shape of the distribution is recovered to a high degree. This does not always happen for the constant and linear methods, especially not for small bin numbers. Implementing the power-law method in a hydrodynamical code thus minimises the numerical cost whilst maintaining high accuracy. The method is not limited to dust grain distributions, but can also be applied to the evolution of any distribution function, such as a cosmic-ray distribution affected by synchrotron radiation or inverse-Compton scattering. 11 pages, 8 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society |
| Databáze: | OpenAIRE |
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