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Self-consistent modelling of aromatic dust species and extinction curves in galaxy evolution
- Publication Year :
- 2020
-
Abstract
- We formulate and calculate the evolution of dust in a galaxy focusing on the distinction among various dust components -- silicate, aromatic carbon, and non-aromatic carbon. We treat the galaxy as a one-zone object and adopt the evolution model of grain size distribution developed in our previous work. We further include aromatization and aliphatization (inverse reaction of aromatization). We regard small aromatic grains in a radius range of 3--50 \AA\ as polycyclic aromatic hydrocarbons (PAHs). We also calculate extinction curves in a consistent manner with the abundances of silicate and aromatic and non-aromatic carbonaceous dust. Our model nicely explains the PAH abundance as a function of metallicity in nearby galaxies. The extinction curve become similar to the Milky Way curve at age $\sim$ 10 Gyr, in terms of the carbon bump strength and the far-ultraviolet slope. We also apply our model to starburst galaxies by shortening the star formation time-scale (0.5 Gyr) and increasing the dense-gas fraction (0.9), finding that the extinction curve maintains bumpless shapes (because of low aromatic fractions), which are similar to the extinction curves observed in the Small Magellanic Cloud and high-redshift quasars. Thus, our model successfully explains the variety in extinction curve shapes at low and high redshifts.<br />Comment: 15 pages, 9 figures, accepted for publication in MNRAS
- Subjects :
- Physics
010504 meteorology & atmospheric sciences
Star formation
Metallicity
Milky Way
Extinction (astronomy)
FOS: Physical sciences
Astronomy and Astrophysics
Quasar
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
01 natural sciences
Astrophysics - Astrophysics of Galaxies
Galaxy
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
0103 physical sciences
Galaxy formation and evolution
Astrophysics::Solar and Stellar Astrophysics
Small Magellanic Cloud
Astrophysics::Earth and Planetary Astrophysics
Physics::Chemical Physics
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
0105 earth and related environmental sciences
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....8eaecb80a4176afc3dcfdf02e53708b0