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Galaxy simulation with the evolution of grain size distribution
- Publication Year :
- 2019
- Publisher :
- arXiv, 2019.
-
Abstract
- We compute the evolution of interstellar dust in a hydrodynamic simulation of an isolated disc galaxy. We newly implement the evolution of full grain size distribution by sampling 32 grid points on the axis of the grain radius. We solve it consistently with the chemical enrichment and hydrodynamic evolution of the galaxy. This enables us to theoretically investigate spatially resolved evolution of grain size distribution in a galaxy. The grain size distribution evolves from a large-grain-dominated ($\gtrsim 0.1~\mu$m) phase to a small-grain production phase, eventually converging to a power-law-like grain size distribution similar to the so-called MRN distribution. We find that the small-grain abundance is higher in the dense ISM in the early epoch ($t\lesssim 1$ Gyr) because of efficient dust growth by accretion, while coagulation makes the small-grain abundance less enhanced in the dense ISM later. This leads to steeper extinction curves in the dense ISM than in the diffuse ISM in the early phase, while they show the opposite trend later. The radial trend is also described by faster evolution in the inner part. We also confirm that the simulation reproduces the observed trend in the relation between dust-to-gas ratio and metallicity, and in the radial gradients of dust-to-gas ratio and dust-to-metal ratio. Since the above change in the grain size distribution occurs at $t\sim 1$ Gyr, the age and density dependence of grain size distribution has a significant impact on the extinction curves even at high redshift.<br />Comment: Accepted for publication into MNRAS, 16 pages, 8 figures
- Subjects :
- Physics
Accretion (meteorology)
010308 nuclear & particles physics
Metallicity
Extinction (astronomy)
FOS: Physical sciences
Astronomy and Astrophysics
Radius
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics - Astrophysics of Galaxies
01 natural sciences
Redshift
Galaxy
Astrophysics - Solar and Stellar Astrophysics
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
0103 physical sciences
Particle-size distribution
Astrophysics::Earth and Planetary Astrophysics
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
Solar and Stellar Astrophysics (astro-ph.SR)
Cosmic dust
Subjects
Details
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....9d71aa928d9f984b657147cb04f09b5e
- Full Text :
- https://doi.org/10.48550/arxiv.1906.01917