2014/05/23

超新星爆発時におけるダストの形成と星間空間へのダスト供給
野沢 貴也（Takaya Nozawa）(National Astronomical Observatory of Japan)
Main collaborators:
T. Kozasa, A. Habe (Hokkaido University)
H. Umeda (University of Tokyo)
K. Maeda (Kyoto University), K. Nomoto (Kavli IPMU)
N. Tominaga (Konan University)

0-1. 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 ejectaof 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) ~ 20-100
Mdust = 0.001-0.01 Msun per AGB (Zhukovska & Gail 2008)
Mdust = 0.1-1.0 Msun per SN (e.g., Nozawa et al. 2003, 2007)

1. Observations of Dust Formationin SNe (and SNRs)

1-1. Summary of observed dust mass in CCSNe

missing cold dust?

young SNRs

supernovae

swept-up IS dust?

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

1-1. Summary of observed dust mass in CCSNe

missing cold dust?

young SNRs

Matsuura+2011

supernovae

Balow+2010

Gomez+2012

swept-up IS dust?

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

1-2. Resolving cool dust in SN 87A with ALMA
ALMA Cycle 0 Proposal‘Detecting cool dust in SN1987A’Band 7 (850 μm)

Band 9 (450 μm)（TN, Tanaka, et al.)2 arcsec

CASA simulation
with extended
config. (4 hrs)

0.1 Msun of silicate➔ 5σ detection at Band 9 !!

1-3. Successful ALMA proposals for SN 1987A

This proposal was ranked
in the highest priority !!

1-3. Successful ALMA proposals for SN 1987A

This proposal was ranked
in the highest priority !!

Our proposal wasnot executedBand 9extended configuration

Band 3, 6, 7, 9
compact configuration

1-4. ALMA reveals dust formed in SN 1987A
SED of 25-years old SN 1987A
blue: Hαgreen: 1.6 µm
red: CO(2-1)

Indebetouw+2014

ALMA spatially resolves cool(~20K) dust of ~0.5 Msun formed inthe ejecta of SN 1987A➔ SNe could be production
factories of dust grains

2. Dust Formation in the ejecta of SNe
at ~1 days
He-coreH-envelope

NS or BH
He–layer (C>O)
O–Ne-Mg layer
Dust formation
Si–Satlayer~1-3 years
afterlayer
explosion
Fe–Ni2-1. Formulation of dust formation
c1c2

J2

c3

J3

αn-1c1cn-1 cnJnβncn

・ master equations

2-2. Non-steady-state nucleation
・ steady-state nucleation rate: Js➔ assuming Js = J2 = J3 = ・・・ = J∞

where μ = 4πa02σ / kT・ non-steady-state dust formation

2-3. Basic equations for dust formation
・ Equation of mass conservation

・ Equation of grain growth

Growth rate is independent of grain radius

2-4. Scaling relation of average grain radius
Nozawa & Kozasa (2013)

CMgSiO3

Λon > 30

Λon > 30

Λon = τsat/τcoll : ratio of supersaturation timescale to gas
collision timescale at the onset time (ton) of dust formation

Λon = τsat/τcoll ∝ τcool ngas
・ fcon,∞ and aave,∞ are uniquely determined by Λon・ steady-state nucleation rate is applicable for Λon > 30

2-5. Dust formation in primordial SNeNozawa+2003, ApJ, 598, 785〇 Population III SNe model (Umeda & Nomoto 2002)‐SNe II ： MZAMS = 13, 20, 25, 30 Msun (E51=1)‐PISNe ： MZAMS = 170 Msun (E51=20), 200 Msun (E51=28)‐nucleation and grain growth theory (Kozasa & Hasegawa 1987)‐no mixing of elements within the He-core‐complete formation of CO and SiO

2-6. Dust formed in Type II-P SNeaverage radius

0.01 μm

condensation time‐a variety of grain species cancondense according to elemental
composition in each layer‐ condensation time:
300-600d after explosion‐ average grain radii: >~0.01 μm
Nozawa+03, ApJ, 598, 785

2-7. Size distribution of newly formed dust
Nozawa+2003, ApJ, 598, 785‐C, SiO2, and Fe grains have lognormal-like size distribution,
while the other grains have power-law size distribution‐The composition and size distribution of dust formed are almost
independent of types of supernova## average grain radius is smaller for PISNe than SNe II-P

2-8. Total mass of dust formed in the ejecta
SNe II‐Total mass of dust is higher for a higher progenitor mass (MZAMS)
SNe II ： mdust = 0.1-1.5 Msun, mdust / mmetal = 0.2-0.3
PISNe ： mdust = 10-30 Msun, mdust / mmetal = 0.3-0.4‐almost all Fe, Mg, and Si are locked up in dust grains, whilemost of C and O remain in the gas-phase (such as CO)➔ dust-to-metal mass ratio is not high for SNe II

3. Evolution of dust in SN remnants
T = (1-2)x104 K
nH,0 = 0.1-1 cm-3

He coreFSRSCD

3-1. Time evolution of SNRs

3-2. Dynamics of dust

3-3. Erosion rate of dust by sputtering3-4. Erosion rate of dust by sputtering
Nozawa+2006, ApJ, 648, 435

projectile: H and He

projectile: oxygen ions・ erosion rate by sputtering quickly increases above
105 K and peaks at 107 -108 K・ erosion rate : da / dt ~ 10-6 nH μm yr-1 cm3for the primordial gas (H and He) at T > 106 K

3-5. Temperature and density of gas in SNRsNozawa+07, ApJ, 666, 955
Model : M pr= 20 Msun (E51=1)
nH,0 = 1 cm-3
Downward-pointing arrows:
forward shock in upper panel
reverse shock in lower panel

The temperature of the gas
swept up by the shocks➔ 106-108 K↓
Dust grains residing in theshocked hot gas are erodedby sputtering3-6. Evolution of dust in SNRs
Nozawa+07, ApJ, 666, 955

Model : Mpr= 20 Msun (E51=1)
nH,0 = 1 cm-3
Dust grains in the He core
collide with reverse shockat (3-13)x103 yr
The evolution of dust heavily
depends on the initial radiusand compositionaini = 0.01 μm (dotted lines)➔ completely destroyedaini = 0.1 μm (solid lines)➔ trapped in the shellaini = 1 μm (dashed lines)➔ injected into the ISM

3-7. Dust mass and size ejected from SN II-P
PISNe
SNe II

total mass of dust surviving thedestruction in Type II SNRs;
0.07-0.8 Msun (nH,0 = 0.1-1 cm-3)
size distribution of dust after theshock-destruction is domimatedby large grains (> 0.01 μm)

Nozawa+07, ApJ, 666, 955
at time of dust formation

after destruction of dust
by reverse shock3-8. Summary of dust production in Pop III SNe‐Various grain species can condense in the ejecta➔ almost all Fe, Mg, and Si are locked up in grains‐The fate of newly formed dust within SNRs strongly
depends on the initial radii and compositions‐The size distribution of dust surviving the destructionin SNRs is weighted to relatively large size (> 0.01 μm).

‐The total mass of dust injected into the ISM decreases
with increasing the ambient gas density
for nH,0 = 0.1-1 cm-3
SNe II-P ➔ Mdust = 0.1-0.8 Msun
➔ significant contribution to dust budget at high z

4. Dust Formation in Type IIb SNe4-1. 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

4-2. 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

4-3. 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 region
Nozawa+10, ApJ, 713, 356

4-4. IR emission from dust in Cas A SNRAKARI corrected 90 μm image

・ 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
Nozawa+10, ApJ, 713, 356

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)

5-1. Dust formation in Type Ia SN○ Type Ia SN modelW7 model (C-deflagration) (Nomoto+1984; Thielemann+1986)‐ 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 forISM density of nH > 0.1 cm-3
➔ SNe Ia are unlikely to bemajor sources of 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