Injection process of dust
from supernovae（超新星爆発による星間ダストの供給過程）

Takaya Nozawa
IPMU (Institute for the Physics and Mathematicsof the Universe, University of Tokyo)
Collaborators;
T. Kozasa (Hokkaido Univ.), A. Habe (Hokkaido Univ.),
H. Umeda (U.T.), K. Maeda (IPMU), E. Dwek (NASA),
N. Tominaga (Konan Univ.), K. Nomoto (IPMU/U.T.)

Outline
1. Introduction
2. Dust formation in Population III SNe(Nozawa et al. 2003, ApJ, 598, 785)

3. Dust evolution in the Population III SNRs
(Nozawa et al. 2007, ApJ, 666, 955)

4. Formation and evolution of dust in Cas A(Nozawa et al. 2010, submitted, astro-ph/0909.4145)

1. Introduction

1-1. Sources of dust in the early universe
・ At an early epoch of the universe (e.g. z > 5), the major
sources of dust are considered to be core-collapse SNe・ Population III stars ➔ very massive (Mpr =100-500 Msun)(e.g., Nakamura & Umemura 2001; Bromm et al. 2002)

In the early universe
・ Type II SNe (SNe II)；Mpr=8-40 Msun

・ pair-instability SNe；Mpr=140-260 Msun
(Heger et al. 2003, ApJ, 591, 288)

1-2. A large amount of dust at z > 5・ The presence of large amounts of dust grains with mass of>10^8 Msun has been confirmed for ~30% of z > 5 quasars(Bertoldi et al. 2003; Priddey et al. 2003; Robson et al. 2004;
Beelen et al. 2006; Wang et al. 2008a, 2008b)
SDSS J1148+5251 at z=6.4

a rapid enrichment with dust
formed in the ejecta of SNe(but see Valiante et al. 2009)

LIR>10^13 Lsun
180 K, β=040 K, β=20.1-1 Msun of dust per SN isrequired to form to explain alarge content of dust at high-zgalaxies

Robson et al. (2004, MNRAS, 351, L29)

(Morgan & Edmunds 2003,Maiolino et al. 2006;
Dwek et al. 2007)

1-3. Extinction curves at high-z
Broad absorption line (BAL) quasars at low-z➔ reddened by dust
SDSS J1048+4637 at z=6.2
GRB 050904 at z=6.3

Maiolino et al. (2004, Nature, 431, 533)

Stratta et al. (2007, ApJ, 661, L9)

Source and evolution of dust at high redshift (z > 5)
are different from those at low redshift (z < 4)

1-4. Role of dust (in the early universe)
・ Dust absorbs starlight and reemits it by thermal radiation➔ plays a crucial role in determining the SFR and the IMF
from observations
・ Dust has great impacts on the formation process of stars－ forming molecules (mainly H2) on the surface(e.g., Cazaux & Spaans 2004; Hirashita & Ferrara 2002)－ controlling the energy balance in the interstellar space－ providing efficient cooling pathways of gas in metal-poor
molecular clouds through thermal emission(e.g., Omukai et al. 2005; Schneider et al. 2006)

Absorption and thermal emission by dust aresensitive to the composition, size, and amount1-5. Aim of our study
In the previous studies, the composition and size ofdust are assumed to be the same as those in Galaxy,
and the amount is treated as a parameterto understand the evolution history of galaxies
from both theoretical and observational studies
It is essential to reveal the evolution ofdust grains throughout the cosmic age!
We aim at revealing the composition, size, andamount of dust by treating the formation anddestruction processes of dust self-consistently

2. Dust Formation in Pop III SNe
at ~1 daysHe-core

H-envelope

NS or BH
He–layer (C>O)
O–Ne-Mg layer
Dust formation
Si–S
layeryears
at ~1-3
afterlayer
explosion
Fe–Ni2-1-1. Calculations of dust formation
・ nucleation and grain growth theory taking accountof chemical reaction at condensation(Kozasa & Hasegawa 1987)

・ key species：
gas species with the least
collision frequency among
reactants

key species controls thekinetics of the nucleationand grain growth2-1-2. Nucleation rate of dust
Steady-state nucleation rate

Supersaturation ratio

2-1-3. Basic equations for dust formation
Equation of conservation for key species

Equation of grain growth2-2. Models of dust formation calculation
・ models of Pop III SNe (Umeda & Nomoto 2002)－ SNe II ： Mpr = 13, 20, 25, 30 Msun (E51=1)－ PISNe ： Mpr = 170 Msun (E51=20), 200 Msun (E51=28)

・ time evolution of gas temperature－ ρ(t) = ρ0 ( t / t0 )-3－ T(t) is calculated by solving the radiative transfer taking
account of energy deposition from 56Ni and 56Co・ mixing of elements within the He-core－ unmixed case (onion-like composition)－ uniformly mixed case (retaining the density profile)・ formation of CO and SiO molecules ➔ complete

2-3. Dust formation in the unmixed ejecta

・ Various dust species (C, MgSiO3, Mg2SiO4, SiO2, Al2O3,MgO, Si, FeS, Fe) form in the unmixed ejecta, reflecting
the elemental composition in each layer
・ The condensation time; 300-600 days for SNe II
400-800 days for PISNe

2-4-1. Dust formed in the unmixed ejecta

・ C, SiO2, and Fe grains have lognormal-like size distribution,
while the other grains have power-law-like size distribution
・ The composition and size distribution of dust formed arealmost independent of types of SNe

2-4-2. Dust formed in the mixed ejecta

・ Because oxygen is rich in the mixed ejecta, only silicates(MgSiO3, Mg2SiO4, SiO2) and oxides (Fe3O4, Al2O3) form
・ The size distribution of each dust species except for Al 2O3
is lognormal-like2-5. Total mass of dust formed
SNe II・ Total dust mass increases with increasing progenitor mass
SNe II ： Mdust = 0.1-2 Msun, fdep = Mdust / Mmetal = 0.2-0.3
PISNe ： Mdust =10-60 Msun, fdep = Mdust / Mmetal = 0.3-0.5
・ Dust mass for the mixed case is generally larger than for
the unmixed case

3. Dust Evolution in Pop III SNRs
T = (1-2)x104 K
nH,0 = 0.1-1 cm-3
(Kitayama et al. 2004;
Machida et al. 2005)

He coreFSRSCD

3-1-1. Time evolution of shock wave

3-1-2. Initial condition for shock wave
・ Hydrodynamical model of SNe (Umeda & Nomoto 2002)
・ SNe II : Mpr=13, 20, 25, 30 Msun (E51=1)
・ PISNe : Mpr=170 (E51=20), 200 Msun (E51=28)

・ The ambient medium (homogeneous)・ gas temperature ; T = 104 K・ gas density ; nH,0 = 0.1, 1, and 10 cm-3

・ Dust Model・ initial size distribution and spatial distribution of dust
➔ results of dust formation calculations
・ treating as a test particle (neglecting the effects of charge)
The calculation is performed from 10 yr up to ~106 yr

3-2-1. Dynamics of dust

3-2-2. Erosion rate of dust by sputtering3-2-3. Erosion rate of dust by sputteringfor primordial composition gas

for oxygen ions・ erosion rate by sputtering quickly increases above 10 5 K
and peaks at 107 -108 K・ da / dt ～ 10-6 nH μm yr-1 cm3 for the primordial gas withT > 106 K (e.g., Nozawa et al. 2006)

3-3.Temperature and density of gas
Model : Mpr=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 this hotgas are eroded by sputtering3-4. Evolution of dust in SNRsModel : Mpr=20 Msun (E51=1)
nH,0 = 1 cm-3
Dust grains in the He core collidewith reverse shock at (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

3-5. Size distribution of surviving dust

The size distribution of surviving dust is greatly deficient insmall-sized grains, compared with that at its formation➔ Dust grains in the early universe are dominatedby large-sized grains (> 0.01 μm)

3-6. Total mass of surviving dust

Total mass of dust surviving the destruction for Type II SNRs;
0.1-0.8 Msun for the unmixed grain model (nH,0 = 0.1-1 cm-3)
0.06-0.7 Msun for the mixed grain model (nH,0 = 0.1 cm-3)➔ high enough to explain dust content at high-z galaxies(Morgan & Edmunds 2003, Maiolino et al. 2006; Dwek et al. 2007)

3-7-1. Flattened extinction curves

flat extinction curve at high redshifts !

Hitashita et al. (2008, 384, 1725, MNRAS)

3-7-2. Effect of grain shattering

Hitashita et al. (2010, accepted , astro-ph/1001.2606)

Summary
・ The fates of dust grains within SN remnants dependon their initial radii and compositions

・ The size distribution of dust surviving the destruction
is weighted to relatively large size (> 0.01 μm)
・ The mass of surviving dust grains decreases withincreasing the ambient gas density
for nH,0 = 0.1-1 cm-3SNe II ➔ Mdust = 0.1-0.8 Msun for the unmixed case
PISNe ➔ Mdust = 0.1-15 Msun
・ Extinction curves in the early universe are expected
to be flat

4. Formation and evolution of dust
in Cassiopeia A SNR

4-1-1. Introduction○ Dust in SNRs
・ CCSNe are important sources of dust?
－ Theoretical studies : 0.01-0.8 Msun
(Bianchi & Schneider 2007; Nozawa et al. 2007)－ Observations : < 10-3 Msun
➔ What kind and how much amount of dust aresupplied by CCSNe?

・ physical processes of dust in shocked gas－ erosion by sputtering and collisional heating・ IR thermal emission from shock-heated dust➔ structure of circumstellar medium and mass-loss
history of progenitor star

4-1-2. Cassiopeia A SNR○ Cas A SNR－ age: ~330 yr (Thorstensen et al. 2001)－ distance: d=3.4 kpc (Reed et al. 1995)－ ejecta mass = 2-4 Msun
－ shock radius (Gotthelf et al. 2001)
Rforw = ~153” (~2.52 pc), Rrev = ~95” (~1.57 pc)➔ dM/dt ~ 2x10-5 (vw/10 km/s) Msun/yr(Chevalier & Oishi 2003)－ oxygen-rich SNR
detection of metal lines such as O, Ar, S, Si, Fe …
thermal emission from ejecta-dust➔ Mdust = 0.02-0.054 Msun (Rho et al. 2008)－ SN type : Type IIb (Mstar=15-20 Msun) (Krause et al. 2008)

4-1-3. Aim of our study
・ Formation of dust in the ejecta of Type IIb SN➔ composition, size, and mass of newly formed dust
➔ dependence of dust formation process on typesof SNe (on the mass of H envelope)・ Evolution of dust in shocked gas within the SNR➔ What fraction of newly formed dust can survive
and is injected into the ISM?

・ Thermal emission from shock-heated dust
➔ comparison with IR observations of Cas A➔ constraint to gas density in the ambient medium

4-2. Model of Type IIb SN○ SN IIb model (SN1993J-like model)－ Meje = 2.94 Msun
MH-env = 0.08 Msun
Mstar = 18 Msun
－ E51 = 1－ M(56Ni) = 0.07 Msun

4-3-1. Composition and mass of dust
condensation time・ different species of dust cancondense in different layers
・ condensation time:300-700 days

mass of dust formed

Total mass of dust formed :0.167 Msun in SN IIb
0.1-1 Msun in SN II-P

4-3-2. Average radii of dust formed
SN IIbGrain radius➔ > 0.01 μm for SN IIP➔ < 0.01 μm for SN IIb
Dust grains formed in Hdeficient SNe are small

SN II-P

SN Ib (SN 2006jc)

Nozawa et al. (2008)

4-4. Calculation of dust evolution in SNR○ Model of calculations(Nozawa et al. 2006, 2007)

・ejecta model－ hydrodynamic model fordust formation calculation
・CSM gas density－ nH,0 = 0.1, 1.0, 10.0 cm-3
－ nH(r) = nH,1 (r / r1)-2nH,1 = 30, 120, 200 cm-3
・treating dust as a test particle－ erosion by sputtering－ deceleration by gas drag1.5 pc(1.6 pc)

2.2 pc(2.5 pc)

4-5-1. Evolution of dust in SNRs
The collision times between
the reverse shock and He coreis 75 year after the explosion➔ much earlier than those(> 1000 yr) for Type II-P

small grains formed in theejecta are quickly trapped in
the hot gas and are completely
destroyed

4-5-2. Time evolution of total dust mass

Almost all newly formed dust grains are destroyed in theshocked gas within the SNR➔ small grain size of newly formed dust➔ early arrival of the reverse shock at the He coreSNe IIb (as well as SNe Ib/c) with low-mass outerenvelope could not be important sources of dust

4-6. Time evolution of IR emission (2)nH,0=10 /cc

Data: Hines et al. (2004)
red: with SH
green: without SH

4-7-1. IR SED for various ambient density

dM/dt = 2x10-5 Msun/yr

Md = 0.008 Msun
dM/dt = 8x10-5 Msun/yr

4-7-2. Contribution from CS dust
・ dust species
C and silicate
・ dust size distributionf(a) ∝ a^-3.5
amin = 0.001 μmamax = 0.5 μm
・ dust-gas ratio: parameterC・ thermal emission fromboth CS grains has apeak at λ~30 μm

Silicategreen: ejecta dust
blue: CSM dust

4-7-3. Contribution from unshocked dustMd,warm ~ 0.008 Msun
Md,cool ~ 0.072 Msun
dM/dt = 8x10-5 Msun/yr・observed SED can bewell reproduced If thetemperature of unshocked
cold dust is around 40 K

Summary1) The radius of dust formed in the ejecta of Type IIb SN isquite small (＜0.01 μm) because of low ejecta density2) Small dust grains formed in Type IIb SN cannot survive
destruction in the shocked gas within the SNR

3) IR SED reflects the destruction and stochastic heating➔ properties (size and composition) of dust
➔ density structure of circumstellar medium4) Model of dust destruction and heating in Type IIb SNR
can reasonably reproduce the observed SED of Cas A;
Md,warm = 0.008 Msun, Md,cool = 0.072 Msun
dM/dt = ~8x10-5 Msun/yr