Formation of Dust in Various
Types of Supernovae
Takaya Nozawa
IPMU (Institute for the Physics and Mathematicsof the Universe, Univ. of Tokyo)
Collaborators
T. Kozasa (Hokkaido University), N. Tominaga (NAOJ),
K. Maeda (IPMU), H. Umeda (UT), K. Nomoto (IPMU/UT)Contents
1. Introduction
2. Formation of dust in Type IIb SN

3. Evolution of dust in Cas A SNR
4. Formation of dust in Type Ia SN1. Introduction

1-1. Introduction
Supernovae are the important sources of dust?
・ theoretical studies of dust formation－ mass of dust formed in the ejecta of SNe II➔ Mform = 0.1-2 Msun
(Todini & Ferrara 2001; Nozawa et al. 2003)
grain size : > 0.01 μm (Nozawa et al. 2003)－ mass of dust surviving the reverse shock➔ Msur = 0.01-1 Msun for nH,0=0.1-10 cm-3
(Nozawa et al. 2007; see also Bianchi & Schneider 2007)

・ a large amount of dust (108 -109 Msun ) for QSOs at z > 5(Bertoldi et al. 2003; Priddy et al. 2003; Robson et al. 2004)➔ 0.1-1 Msun of dust per SN II are required to form
to explain dust budget in high-z QSO systems(Morgan & Edmunds 2003; Dwek et al. 2007)

1-2. Introduction○ IR observaitons of dust-forming SNe (~10 SNe)
Mdust = 10-5-10-3 Msun
SN 1987A ➔ 10-4-10-3 Msun (Elcolano et al. 2007)
SN 2003gd ➔ 0.02 Msun (Sugerman et al. 2006)➔ 4x10-5 Msun (Miekle et al. 2007)
SN 2006jc ➔ ~7x10-5 Msun (Sakon et al. 2008)➔ 6x10-6 Msun (Smith et al. 2008) , 3x10-4 Msun (Mattila et al 2008)○ IR observaitons of nearby young SNRs
Mdust = 10-4-10-2 Msun(e.g., Hines et al. 2004, Temim et al. 2006; Morton et al. 2007)

Theoretical predictions overestimate dust mass?
Observations are seeing only hot dust (＞100K)?
Thermal emission from dust is optically thin?

1-3. Aim of our study
・ Cas A SNR (SN type : IIb)
－dust formation in the ejecta of a SN
－dust evolution in the shocked gas within SNRs

How much and what kind of dust are supplied by SNe?
・ Dust-forming SNe・Type IIp (SN1999em, SN 2003gd) ➔ 400-500 days
・Type IIn (SN1998S)➔ ~230 days
・Type Ib (SN1990I, SN 2006jc) ➔ ~230 days
・Type Ic➔ not observed

・Type Ia

➔ not observed

Formation process of dust in the ejecta depends
on the type of SNe?

1-4. Cassiopeia A SNR○ Cas A SNR (SN 1671)
age: 337yr (Thorstensen et al. 2001)
distance: d=3.4 kpc (Reed et al. 1995)
radius: ~150” (~2.5 pc)
SN type : Type IIb (MMS=15-25 Msun)

Krause et al. (2008)

1-5. Latest estimate of dust mass in Cas A(Rho et al. 2008)

onion-like elemental composition remains➔ Mdust = 0.02-0.054 Msun

2. Formation of dust in Type IIb SN

2-1. Dust formation calculation○ Type IIb SN model－ MMS = 18 Msun
Mej = 2.94 Msun
MH-env = 0.08 Msun
－ E51 = 1－ M(56Ni) = 0.07 Msun

○ Dust formation theory－ non-steady nucleation andgrain growth theory(Nozawa et al. 2003)－ onion-like composition－ sticking probability; αs = 1

2-2. Mass and average radius of dust formed
Mass of dust formed

average radius

Total mass of dust formed in
SN IIb is consistent with thatin SN IIp

Low gas density in SN IIb
prevents dust grains fromgrowing up to large-sized(> 0.01μm) grain

2-3. Cumulative size spectrum of dust in mass
SN IIp (MMS=20 Msun)

SN IIb (MMS=18 Msun)

Grain radius➔ > 0.01 μm for SN IIp➔ < 0.01 μm for SN IIb
Dust grains formed in H-deficient SNe can be small

3. Evolution of dust in Cas A SNR

3-1. Calculation of dust evolution in SNRs
○ Model of calculations(Nozawa et al. 2006, 2007)

・ejecta model－ hydrodynamic model fordust formation calculation
・ISM－ homogeneous, Tgas=104 K－ nH = 1.0 and 10.0 cm-3
－ solar composition of gas・treating dust as a test particle－ erosion by sputtering－ deceleration by gas drag－ collsiional heating3-2. Evolution of dust in Cas A SNR
n=1.0 /cc

n=10.0 /cc

3-3. Time evolution of dust mass
n=1.0 /cc

n=10.0 /cc

Mdust ~ 10-4 Msun at 105 yr

Mdust = 0 Msun at 105 yr

Core-collapse SNe with thin H-envelope cannot be themain sources of dust
The radius of dust formed in the peculiar Type Ib SN 2006jc(MMS=40 Msun, E51=10) is small (< 0.01 μm) (Nozawa et al. 2008)

3-4. Thermal emission from dust in the SNR・ thermal radiation from dust ← temperature of dust
・ equilibrium temperature of dust in SNR is determined bycollisional heating with gas and radiative cooling
H (a, n, Tg)= Λ(a, Qabs, Td) ➔ thermal emission
・ small-sized dust grains (＜0.01 μm) ➔ stochastic heating3-5. Comparison with Cas A observation (1)Data: Hines et al. (2004)
red: with SH
green: without SH

3-6. Comparison with Cas A observation (2)Data: Hines et al. (2004)
Dust mass of 0.04 Msun is consistent
red:withwithmass
SH of dust(~0.02-0.054 Msun) in Cas A derivedgreen:
by Rhoet al. (2008)
withoutSH

4. Formation of dust in Type Ia SN

4-1. Dust formation calculation for SN Ia○ Type Ia SN modelW7 model (C-deflagration)(Thielemann et al. 1986)－ Mpr = 1.38 Msun

－ E51 = 1
－ M(56Ni) = 0.6 Msun

○ Dust formation theory－ non-steady nucleation andgrain growth theory(Nozawa et al. 2003)－ onion-like composition－ sticking probability; αs = 1

4-2. Results of dust formation calculation
Condensation time

Average radius of grain

Condensation time of dust : 100-300 days
Average radius of dust : < 0.01 μm

4-3. Mass of dust formed in SN Ia
Mass of dust formed
Optical depth at 300 days

Total mass of dust
Mdust =0.047 Msun

τ(0.55) ~ 100τ(0.55) ~ 60 by C grains
τ(0.55) ~ 35 by Si and FeSgrains➔ too high4-4. NLTE dust formation
Early formation of dust ➔ 100-300 days
Large M(56Ni)➔ 0.6 Msun

lnS’ (Tv) = lnS(T) +0.5 ln(T/Tv)

4-5. Dust temperature

F(r)= L / 4 π r^2

4-6. mass of dust formed
Mass of dust formed

There is no evidence that C
has been detected in SN Ia

If we ignore C grains in SN Ia
Mdust = 5x10^-3
τ(0.55) ~ 0.8 at 300 day

Summary1) The size of dust formed in the ejecta of Type IIb SN isrelatively small because of low gas density of the ejecta
2) Newly formed dust grains in Type IIb SN cannot survive
the reverse shock since their radii are small (＜0.01 μm)

3) Model of dust destruction and heating in Type IIb SNR
for nH=10.0 cm-3 reproduces the observed SED of Cas A➔ circumstellar / interstellar dust
➔ density structure of circumstellar medium➔ thermal emission from dust at various positions4) For Type Ia SN, the effect of radiation on dust formation
can be important