2013/05/30

Dust in the ejecta of supernovae
Takaya Nozawa
Kavli IPMU (Kavli Institute for the Physics andMathematics of the Universe)

Collaborators:
K. Maeda, K. Nomoto (Kavli IPMU)
T. Kozasa, A. Habe (Hokkaido University)
H. Umeda (U.T.), N. Tominaga (Konan Univ.)

1-1. Introduction〇 SNe (and SNRs) are sources of－ cosmic ray－ kinetic and radiative energies－ heavy elements－ dust grains

1-2. Sources of dust in our Galaxy
Milky Way (optical)

Milky Way (infrared)

SNe are important sources of interstellar dust?
－ number (occurrence) ratio of SNe to AGB starsn(SNe) / n(AGB stars) ~ 0.05-0.1
Mdust = 0.1-1.0 Msun per SN (Nozawa et al. 2003; 2007)
Mdust = 0.01-0.05 Msun per AGB (Zhukovska & Gail 2008)

1-3. Sources of dust in the early universe
huge amounts of dust grains (>108 Msun) are detectedin host galaxies of quasars at redshift z > 5 (< 1 Gyr)
➔ SNe arising from short-lived massive stars must
be main producers of dust
➔ 0.1 Msun of dust per SN is needed to be ejected toexplain such massive dust at high-z (Dwek et al. 2007)

theoretical studies predict that
0.1-1.0 Msun of dust forms in SNe(e.g., Nozawa et al. 2003)

N/MIR observations of nearby
SNe detect only < 10-3 Msun(e.g., Meikle et al. 2011)

z=6.4, at 350 μm

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

Cas A

young SNRs

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

What fraction of the newly formed grains can survive tobe injected into the interstellar space?

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

Cas A

young SNRs

swept-up IS dust?

FIR to sub-mm observations
have revealed the presence
young SNeof massive (>0.1 Msun) dust grains in the ejecta of CCSNe
by courtesy of M. Tanaka

What fraction of the newly formed grains can survive tobe injected into the interstellar space?

2-2. Emission and absorption efficiency of dust
○ Thermal radiation from a dust grain
Fλ ∝ 4πa2 Qemis(a,λ) πBλ(Tdust) # Qemis = Qabs
carbonsilicate(Qemis/a) is independent of aFλ ∝ 4πa3 (Qemis[a,λ]/a) πBλ(Tdust)∝ 4 Mdust κemis(λ) πBλ(Tdust)➔ IR emission is derived given Mdust, κabs, and Tdust2-3. Composition of dust formed in SNe
IS dust : carbonaceous grain andsilicate (MgSiO3, MgFeSiO4, …)
SN 2004et

SN 2006jc

silicate➔ 1750 K

silicate

carbon

SN 2004et, Kotak+09

carbon➔ 1660 K

SN 2006jc, Smith+08

3. Formation and evolution of dustin supernovae

He coreFSRSCD

3-1. Dust formed in Type II-P SNeaverage radius
0.01 μm

SN model: Umeda & Nomoto+02

Condensation time

－ various dust species form
according to compositionof gas in each layer－ condensation time:
300-600d after explosion－ average radii: >~0.01 μm
Nozawa+03, ApJ, 598, 785

3-2. Evolution of dust in SNRs
Nozawa+07, ApJ, 666, 955

Model : Type II-P
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

3-3. Mass and size of dust ejected from SN II-P
Nozawa+2007, 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 dust after
RS destruction is domimatedby large grains (> 0.01 μm)

at time of dust formation

after destruction of dust
by reverse shock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－ 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
newlyformed
dust
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. Scaling relation of average grain radiuscarbonsilicateΛon: ratio of supersaturation timescale to gas collisiontimescale at the time of dust formation

Λon = τsat/τcoll ∝ τcool ngas
where τcool = ton / 3 (γ – 1)
Nozawa & Kozasa in prep

5-2. Dust formation in Type IIn SN 2010jl
carbonT = 1300 K

MgSiO
3 grains
silicate
T = 1450 K

Dust in SN 2010jl
・ carbon grains
・ grain radius: <0.1μm(possibly <0.01 µm)
・ dust mass: ~10-3 Msun
Maeda, TN, et al. 2013

5-3. Average grain size in SNe 2010jl and 1987Acarbon

SN 2010jl

SN 2010jl

・ ton: 550 day・ ngas < 109 cm-3SN 1987A

grain radius < 0.08 µm
Dust formation incool dense shell

SN 1987A

・ grain radius: ~0.01-0.05 μm(Kozasa et al. 1989; Todini & Ferrara 2001)

・ dust formation in clumps?

6. Summary of this talk
〇 There are increasing pieces of observational evidence
that CCSN is a production factory of massive dust
➔ in good agreement with 0.1-1 Msun predicted by theory➔ few observation to identify the composition and size of dust

〇 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) : aave < 0.01 μm➔ H-stripped SNe are likely to be poor producers of dust

〇 We construct the universal relation to describe theaverage radius of newly formed dust grains➔ being useful, given gas density and formation time of dust

➔ explaining grain size derived from observations of SN 2010jl