Evolution of dust extinction curves in galaxy simulation

Kuan Chou Hou, Hiroyuki Hirashita, Kentaro Nagamine, Shohei Aoyama, Ikkoh Shimizu

Research output: Contribution to journalArticlepeer-review

41 Scopus citations

Abstract

To understand the evolution of extinction curve, we calculate the dust evolution in a galaxy using smoothed particle hydrodynamic simulations incorporating stellar dust production, dust destruction in supernova shocks, grain growth by accretion and coagulation, and grain disruption by shattering. The dust species are separated into carbonaceous dust and silicate. The evolution of grain size distribution is considered by dividing grain population into large and small grains, which allows us to estimate extinction curves. We examine the dependence of extinction curves on the position, gas density and metallicity in the galaxy, and find that extinction curves are flat at t ≲ 0.3 Gyr because stellar dust production dominates the total dust abundance. The 2175 Å bump and far-ultraviolet (FUV) rise become prominent after dust growth by accretion. At t ≲ 3 Gyr, shattering works efficiently in the outer disc and lowdensity regions, so extinction curves show a very strong 2175 Å bump and steep FUV rise. The extinction curves at t ≲ 3 Gyr are consistent with the Milky Way extinction curve, which implies that we successfully included the necessary dust processes in the model. The outer disc component caused by stellar feedback has an extinction curve with a weaker 2175 Å bump and flatter FUV slope. The strong contribution of carbonaceous dust tends to underproduce the FUV rise in the Small Magellanic Cloud extinction curve, which supports selective loss of small carbonaceous dust in the galaxy. The snapshot at young ages also explains the extinction curves in high-redshift quasars.

Original languageEnglish
Pages (from-to)870-885
Number of pages16
JournalMonthly Notices of the Royal Astronomical Society
Volume469
Issue number1
DOIs
StatePublished - 1 Jul 2017
Externally publishedYes

Keywords

  • Dust, extinction
  • Galaxies: Evolution
  • Galaxies: ISM
  • Galaxy: Evolution
  • Magellanic Clouds
  • Methods: numerical

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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