2012/10/17

ダスト形成から探る超新星爆発
Supernovae probed by dust formation

野沢 貴也（Takaya Nozawa）
東京大学 国際高等研究所
カブリ数物連携宇宙研究機構（Kavli IPMU）

1-1. Introduction
・ SNe are important sources of interstellar dust?
・ abundant metal (metal : N > 5)・ low temperature (T < ~2000 K)・ high density (n > ~106 cm-3)

mass-loss windsof AGB stars
expanding ejecta
of supernovae－ huge amounts of dust grains (>108 Msun) are detectedin host galaxies of quasars at redshift z > 5➔ 0.1 Msun of dust per SN is needed to explain suchmassive dust at high-z (e.g. Dwek et al. 2007)－ contribution of dust mass from AGB stars and SNen(AGB stars) / n(SNe) ~ 10-20
Mdust = 0.01-0.05 Msun per AGB (Zhukovska & Gail 2008)
Mdust = 0.1-1.0 Msun per SN (Nozawa et al. 2003; 2007)

1-2. Summary of observed dust mass in CCSNe
SN1987A
Crabtheory
missing cold dust?

Cas A

young SNRs

swept-up IS dust?
young SNeby courtesy of M. Tanaka

Far-IR to sub-mm observations are essential for revealing
the mass of dust grains produced in the ejecta of SNe1-2. Summary of observed dust mass in CCSNe
SN1987A
Crabtheory
missing cold dust?

Cas A

young SNRs

swept-up IS dust?
young SNeby courtesy of M. Tanaka

Far-IR to sub-mm observations are essential for revealing
the mass of dust grains produced in the ejecta of SNe

1-3. Origin of IR emission from SNe
Dust formation in the ejecta

Dust formation in dense shellIR echo by CS dust

Shock heating of CS dust

1-4. Evidence for dust formation in SN 2006jc
KHJDi Calro+08
Tominaga+08

・ brightening of IR
・ rapid decline of optical light・ blueshift of emission lines
formation of CO and SiO molecules(more robust if SiO are depleted)

Tominaga+08

Smith+08

2-1. Dust formation theoryc1c(2)

J1c(3)J2c(n+1)

Jn〇 Nucleation and grain growth theory

αs: sticking coefficient ➔ αs = 1

2-1. Dust formed in Type II-P SNeaverage radius
0.01 μm

Umeda & Nomoto+02

Condensation time

Nozawa+03, ApJ, 598, 785－ condensation time:
300-600d after explosion－ average radii: >~0.01 μm－ total dust mass: 0.57 Msun
➔ dust mass injected into
the ISM: ~0.1-0.8 Msun

3-1. Peculiar dust-forming SN : SN 2006jc
Tominaga+08

Sakon+09

800K aC

at 200day

320K aC・ re-brightning of NIR
・ rapid decline of optical light・ blueshift of He I narrow lines

・ 800 K aC
➔ newly formed dust:
Mdust = 7x10-5 Msun

ongoing formation of dust
from ~50 days in SN2006jc

・ 320 K aC
➔ preexisting CS dust:
Mdust = 3x10-3 Msun

3-2. Dust formation in Type Ib SN : SN 2006jc○ SN 2006jc model (Tominaga+08)

average radius－ Meje = 4.9 Msun (MZAMS = 40 Msun)－ E51 = 10 (hypernova-like)－ M(56Ni) = 0.22 Msun

0.01 μm

low ejecta mass and highexplosion energy leads too
low gas density➔ The radii of newly formed
grains are below <0.01 µm

3-3. Unified understanding of SN 2006jc
Formation ofwarm C grains

Nozawa+08

energetic Type Ib➔ early formationof C dust

800K aC

320K aC

Sakon+09

preexisting C dust
➔ WC progenitor

Tominaga+08

4-1. Dust formation in Type IIb SN○ SN IIb model (SN1993J-like model)－ Meje = 2.94 MsunMZAMS = 18 Msun
MH-env = 0.08 Msun

－ E51 = 1－ M(56Ni) = 0.07 Msun

4-2. Dependence of dust radii on SN typeSN IIb

SN II-P0.01 μm－ the radius of dust formedin H-stripped SNe is small－ condensation time of dust
300-700d after explosion

・ SN IIb without massive
H-env ➔ adust < 0.01 μm－ total mass of dust formed
・ 0.167 Msun in SN IIb
・ 0.1-1 Msun in SN II-P・ SN II-P with massive
H-env ➔ adust > 0.01 μm

Nozawa+10, ApJ, 713, 356

4-3. Evolution of dust in Type IIb SNRTime evolution of dust mass

predicted IR SED at 330 yr

330 yrAlmost all newly formed
grains are destroyed inshocked gas in the SNR
Herschelobservation
due to small
radius ofMd,cool= 0.075
Msun
newly
formeddust
Tdust ~ 35 K
(Barlow+10)
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

5-1. 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

5-2. Dust formation and evolution in SNe Ia
average radius

Nozawa+11, ApJ, 736, 45

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 Msun

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

5-3. Carbon dust and outermost layer
・ There has been no evidence for dust formation in SNe Ia➔ Formation of massive carbon dust does not matchthe observations－ C dust mass: ~0.001 Msun
－ massive unburned carbon(~0.05 Msun) in deflagration

observationally estimatedcarbon mass in SNe Ia :Mc < 0.01 Msun
(Marion+06; Tanaka+08)

Observational data: SN 2005df at
day 200 and 400 (Gerardy+07)

The presence of unburned
carbon-rich layer always
involve formation of C dust

5-4. Dust formation in super-Chandra SNe?
－ super-Chandra SNe :M(56Ni) ~ 1.0 Msun

SN 2009dc, Tarbenberger+’10

detection of CII line
➔ presence of massive
unburned carbon
SN 2006gz, Maeda+09

enhanced fading at ~200 day➔ formation of carbon dust?

6. Summary of this talk・ SNe II-P can inject a large amount of dust (>0.1 Msun)－ almost all Mg, SI, and Fe atoms are trapped in dust
－ FIR observations of SNe support massive dust・ 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

・ Formation of C dust in SNe Ia may give some hints onthe composition of outermost layers