Galactic Archaeology: Near-Field Cosmology and the Formation of the Milky Way
ASP Conference Series, Vol. 458
W. Aoki, M. Ishigaki, T. Suda, T. Tsujimoto, N. Arimoto, eds.
c 2012 Astronomical Society of the PacificFormation and Evolution of Dust in Various Types of Supernovae
T. Nozawa,1 T. Kozasa,2 K. Maeda,1 K. Nomoto,1 H. Umeda,3 N. Tominaga,4and A. Habe2
1 Institute for the Physics and Mathematics of the Universe, TODIAS,

University of Tokyo, Kashiwa, Chiba 277-8583, Japan
2 Department of Cosmosciences, Graduate School of Science, Hokkaido

University, Sapporo 060-0810, Japan
3 Department of Astronomy, School of Science, University of Tokyo, Bunkyo-ku,Tokyo 113-0033, Japan
4 Department of Physics, Faculty of Science and Engineering, Konan

University, Okamoto, Kobe 658-8501, Japan
Abstract.
We demonstrate how the formation and destruction processes of dustin supernovae (SNe) depend on the type of SNe classified through the mass of theirouter envelopes. We show that, for Type II-P SNe with massive hydrogen envelopes,
relatively large grains (>0.01µm) can condense in the ejecta, and that ∼0.1–1 M⊙ of∼dust can be injected into the interstellar medium. On the other hand, for Type IIb/Ib/Ia
SNe with no massive envelope, the radii of newly formed grains are considerably small,less than 0.01 µm, so the dust grains are almost completely destroyed in the shocked hotgas. These results suggest that envelope-retaining SNe can be major sources of dust,
whereas envelope-deficient SNe are likely to be minor dust sources.

1. Introduction
Supernovae (SNe) are considered to be rapid and efficient producers of dust grains.
In the ejecta of SNe, dust grains can form within the He core where the densities ofcondensible heavy elements are much higher than in the outer envelope. On the other
hand, the newly formed dust can subsequently undergo the erosion due to sputtering in
the hot gas swept up by the reverse and forward shocks. Thus, the size distribution andmass of dust finally ejected from SNe to the interstellar medium (ISM) are regulated bythese two processes. However, both processes depend on the type of SNe through theirenvelope mass. In this proceedings, to show this dependence, we describe the results
for a series of our works on the calculations of dust formation in the ejecta of various
types of SNe and dust destruction in the shocked gas inside the SN remnants (SNRs).
2. Dust Formation and Evolution in Type II-P SNe
Type II-P SNe (SNe II-P) are core-collapse SNe (CCSNe) that retain massive H envelopes at the explosions. Nozawa et al. (2003) find that 0.1–1 M⊙ of dust grains can135

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condense in the ejecta of SNe II-P and that the grain radii range from 0.0005 µm up
to 1.0 µm, with the average radius larger than ∼0.01 µm. Meanwhile, the fates of thenewly formed grains within SNRs depend on their initial radii aini (Nozawa et al. 2007);small grains of aini <∼ 0.01–0.05 µm are trapped in the hot gas to be entirely destroyed,
while larger grains are injected into the ISM without being eroded significantly. Forinterstellar hydrogen densities of nH,0 = 1.0–0.1 cm−3 , SNe II-P can supply 0.07–0.8
M⊙ of dust to the ISM, so that SNe II-P can be primary sources of interstellar dust.
3. Dust Formation and Evolution in Type IIb/Ib SNeType IIb/Ib SNe (SNe IIb/Ib) are CCSNe that have lost almost all or all of their H envelopes before the explosions. Because of the less massive envelopes, SNe IIb/Ib havevery high expansion velocities of the He core, resulting in much lower gas densities
than in SNe II-P. The dust formation calculations in a SN Ib (Nozawa et al. 2008) anda SN IIb (Nozawa et al. 2010) show that the total masses of dust formed in SNe IIb/Ib
are in the range of 0.1–1.5 M⊙ and are comparable with the dust mass formed in SNeII-P. However, too low gas density in the He core of SNe IIb/Ib prevents dust grainsfrom growing up to the radii larger than 0.01 µm. Nozawa et al. (2010) also investigate
the evolution of dust in the Type IIb SNRs. They find that the newly formed grains arealmost completely destroyed in the hot gas for the ISM densities of nH,0 ≥ 0.1 cm−3 .
This is because the grain radii are considerably small and because the early arrival of
the reverse shock at the He core causes more efficient destruction of dust. Given thatboth of these result from the small-mass envelopes of SNe IIb/Ib, envelope-stripped
CCSNe are not expected to furnish a significant amount of dust to the ISM.
4. Dust Formation and Evolution in Type Ia SNe
Type Ia SNe (SNe Ia) are considered to be thermonuclear explosions of C–O whitedwarfs that have released the H and He envelopes during their evolutions. Nozawa etal. (2011) show that at most ∼0.1–0.2 M⊙ of dust can condense in the ejecta of SNe Ia.
On the other hand, as is the case of SNe IIb/Ib, the gas density in SNe Ia is much lower
than SNe II-P, so the radii of newly formed grains are found to be below ∼0.01 µm.
Therefore, these small grains cannot survive the destruction within the SNRs, whichallows us to conclude that SNe Ia may not be important sources of interstellar dust.
Acknowledgments. This research has been supported in part by World PremierInternational Research Center Initiative (WPI Initiative), MEXT, Japan, and by the
Grant-in-Aid for Scientific Research of the Japan Society for the Promotion of Science(20340038, 22684004, 23224004).
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