TERRAPUB Earth, Planets and Space

Earth Planets Space, Vol. 65 (No. 3), pp. 213-222, 2013

Dust formation history of galaxies: A critical role of metallicity for the dust mass growth by accreting materials in the interstellar medium

Ryosuke S. Asano1, Tsutomu T. Takeuchi1, Hiroyuki Hirashita2, and Akio K. Inoue3

1Department of Particle and Astrophysical Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
2Academia Sinica Institute for Astronomy and Astrophysics, P. O. Box 23-141, Taipei 10617, Taiwan
3College of General Education, Osaka Sangyo University, 3-1-1 Nakagaito, Daito, Osaka 574-8530, Japan

(Received November 7, 2011; Revised April 22, 2012; Accepted April 27, 2012; Online published March 12, 2013)

Abstract: This paper investigates the main driver of dust mass growth in the interstellar medium (ISM) by using a chemical evolution model of a galaxy with metals (elements heavier than helium) in the dust phase, in addition to the total amount of metals. We consider asymptotic giant branch (AGB) stars, type II supernovae (Sne II), and dust mass growth in the ISM, as the sources of dust, and SN shocks as the destruction mechanism of dust. Furthermore, to describe the dust evolution precisely, our model takes into account the age and metallicity (the ratio of metal mass to ISM mass) dependence of the sources of dust. We have particularly focused on the dust mass growth, and found that in the ISM this is regulated by the metallicity. To quantify this aspect, we introduce a "critical metallicity", which is the metallicity at which the contribution of stars (AGB stars and Sne II) equals that of the dust mass growth in the ISM. If the star-formation timescale is shorter, the value of the critical metallicity is higher, but the galactic age at which the metallicity reaches the critical metallicity is shorter. From observations, it was expected that the dust mass growth was the dominant source of dust in the Milky Way and dusty QSOs at high redshifts. By introducing a critical metallicity, it is clearly shown that the dust mass growth is the main source of dust in such galaxies with various star-formation timescales and ages. The dust mass growth in the ISM is regulated by metallicity, and we emphasize that the critical metallicity serves as an indicator to judge whether the grain growth in the ISM is the dominant source of dust in a galaxy, especially because of the strong, and nonlinear, dependence on the metallicity.
Key words: Dust, extinction, galaxies: infrared, galaxies: evolution, galaxies: starburst, stars: formation.

Corresponding author E-mail: asano.ryosuke@g.mbox.nagoya-u.ac.jp

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