Formation of dust in the ejecta of type Ia supernovae

Takaya Nozawa, Keiichi Maeda, Takashi Kozasa, Masaomi Tanaka, Ken'Ichi Nomoto, Hideyuki Umeda

研究成果: Article査読

62 被引用数 (Scopus)


We investigate the formation of dust grains in the ejecta of Type Ia supernovae (SNe Ia), adopting the carbon-deflagration W7 model. In the calculations of dust formation, we apply the nucleation and grain growth theory and consider the two extreme cases of the formation of CO and SiO molecules: complete formation and no formation. The results of the calculations show that for the sticking probability of αj = 1, C, silicate, Si, and FeS grains can condense at early times of ∼100-300days after the explosion, whereas Fe and SiC grains cannot form substantially. Due to the low gas density in SNe Ia with no H-envelope, the average radii of the newly formed grains are generally below 0.01 μm, being much smaller than those in Type II-P SNe. This supports our previous conclusion that the radius of dust formed in the ejecta is smaller in SNe with less massive envelopes. The total dust mass ranges from 3 × 10-4 M to 0.2 M for αj = 0.1-1, depending on whether or not CO and SiO molecules are formed. We also estimate the optical depths and thermal emission by the newly formed dust and compare them to the relevant observations of SNe Ia. We find that the formation of C grains in SNe Ia must be suppressed to be consistent with observational constraints. This implies that energetic photons and electrons heavily depress the formation efficiency of C grains or that the outermost C-O layer of SNe Ia is almost fully burned. Finally, we calculate dust destruction in the SN remnants and find that dust grains formed in the ejecta of SNe Ia are almost completely destroyed in the shocked gas before being injected into the interstellar medium. This indicates that SNe Ia are unlikely to be the major sources of interstellar dust.

ジャーナルAstrophysical Journal
出版ステータスPublished - 2011 7 20

ASJC Scopus subject areas

  • 天文学と天体物理学
  • 宇宙惑星科学


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