Supernovae as sources ofinterstellar dust
星間ダストの供給源としての超新星

Takaya Nozawa(IPMU, University of Tokyo)
Collaborators:
T. Kozasa, A. Habe (Hokkaido Univ.),
K. Maeda, K. Nomoto, M. Tanaka (IPMU),
N. Tominaga (Konan Univ.), H. Umeda, I. Sakon (U.T.)
2011/03/02

1-1. Introduction
Supernovae are important sources of dust?
・ Evolution of dust throughout the cosmic age－ A large amount of dust (> 108 Msun) in z > 5 quasars－ Inventory of interstellar dust in our Galaxy

・ Possible formation sites of dust
－ metal-rich ejecta of supernovae (Type II/Ib/Ic and Ia)－ mass-loss winds of AGB stars－ grain growth in the ISM (molecular clouds)－ mass-loss winds of massive (RG and WR) stars,
novae, quasar outflow …

1-2. Mass and size of dust ejected from SN II-P
Nozawa+07, ApJ, 666, 955
SNe II-P

total dust mass surviving thedestruction in Type II-P SNRs;
0.07-0.8 Msun (nH,0 = 0.1-1 cm-3)

size distribution of surviving
dust is domimated by large
grains (> 0.01 μm)

at time of dust formation

after destruction of dust
by reverse shock2-1. Dust formation in Type IIb SN○ SN IIb model (SN1993J-like model)－ Meje = 2.94 Msun
MZAMS = 18 Msun
MH-env = 0.08 Msun
－ E51 = 1－ M(56Ni) = 0.07 Msun

2-2. Dependence of dust radii on SN type
SN IIbSN II-P

0.01 μm－ condensation time of dust
300-700 d after explosion－ the radius of dust formedin H-stripped SNe is small－ total mass of dust formed
・ 0.167 Msun in SN IIb
・ 0.1-1 Msun in SN II-P・ SN IIb without massive
H-env ➔ adust < 0.01 μm

Nozawa+10, ApJ, 713, 356

・ SN II-P with massive
H-env ➔ adust > 0.01 μm

2-3. Destruction of dust in Type IIb SNR
homogeneous CSM (ρ = const)

stellar-wind CSM (ρ ∝ r-2)
330 yrnH,1 = 30, 120, 200 /cc ➔ dM/dt = 2.0, 8.0, 13x10-5 Msun/yr for vw=10 km/s

Almost all newly formed grains are destroyed in shockedgas within the SNR for CSM gas density of nH > 0.1 /cc➔ small radius of newly formed dust
➔ early arrival of reverse shock at dust-forming regionNozawa+10, ApJ, 713, 356

2-4. IR emission from dust in Cassiopeia A SNR
Nozawa+10, ApJ, 713, 356

・ total mass of dust formed
Mdust = 0.167 Msun・ shocked dust : 0.095 Msun
Md,warm = 0.008 Msun
・ unshocked dust :Md,cool = 0.072 Msun
with Tdust ~ 40 K

AKARI corrected 90 μm image

AKARI observation
Md,cool = 0.03-0.06 Msun
Tdust = 33-41 K(Sibthorpe+10)

Herschel observation
Md,cool = 0.075 Msun
Tdust ~ 35 K (Barlow+10)

3-1. Difference in estimate of dust mass in SNe
・ Theoretical studies－ at time of dust formation : Mdust=0.1-1 Msun in CCSNe(Nozawa+03; Todini & Ferrara 01; Cherchneff & Dwek 10)－ after destruction of dust by reverse shock (SNe II-P) :Msurv~0.01-0.8 Msun (Nozawa+07; Bianchi & Schneider 07)

dust amount needed to explain massive dust at high-z
・ Observational works－ MIR observations of SNe : Mdust < 10-3 Msun(e.g., Ercolano+07; Sakon+09; Kotak+09)－ submm observations of SNRs : Mdust > 1 Msun(Dunne+03; Morgan+03; Dunne+09; Krause+05)－ MIR/FIR observation of Cas A : Mdust=0.02-0.075 Msun
(Rho+08; Sibthorpe+09; Barlow+10)

3-2. Missing-dust problem in CCSNe
Tanaka, TN, +11, submitted
theory3-3. Detectability of SNe-dust with SPICA
Tanaka, TN, +11, submitted

Massive dust can behidden if Tdust < 100 K

3-4. Detectability of cold dust with ALMA
Md,warm = 0.008 Msun
Md,cool = 0.072 Msun
with Tdust = 43 K

SN1987A
MIR image－ SN 1987A in LMC
diameter : 2”, most feasible－ 1E0102.2-7219 in SMC
diameter : 40”
too extended to be detected(Gemini T-ReCS, Bouchet+04)➔ integration time : ~100 day4-1. Dust formation in Type Ia SN○ Type Ia SN modelW7 model (C-deflagration) (Nomoto+84; Thielemann+86)－ Meje = 1.38 Msun

－ E51 = 1.3－ M(56Ni) = 0.6 Msun

4-2. Dust formation and evolution in SNe Ia
average radius

Nozawa+11, submitted
dust destruction in SNRs

0.01 μm

・ condensation time :100-300 days
・ average radius of dust :aave <~ 0.01 μm
・ total dust mass :Mdust = 0.1-0.2 Msun

newly formed grains arecompletely destroyed for
ISM density of nH > 0.1 cm-3
➔ SNe Ia are unlikely to bemajor sources of dust

5. Summary of this talk・ Size of newly formed dust depends on types of SNe－ H-retaining SNe (Type II-P) : aave > 0.01 μm－ H-stripped SNe (Type IIb/Ib/Ic and Ia) : aave < 0.01 μm➔ dust is almost completely destroyed in the SNRs
➔ H-stripped SNe may be poor producers of dust
・ Our model treating dust formation and evolution selfconsistently can reproduce IR emission from Cas A
・ Mass of dust in SNe must be dominated by cool dust
－ FIR and submm observations of SNe are essential－ SPICA will make great advances on understandingof dust formation process in SNe