2014/06/25

Current understandings on dust
formation in supernovae
Takaya Nozawa(NAOJ, Division of theoretical astronomy)

Main collaborators:
Masaomi Tanaka (NAOJ, theory)
Keiichi Maeda (Kyoto University)
Takashi Kozasa, Asao Habe (Hokkaido University)
Hideyuki Umeda (University of Tokyo)
Ken’ichi Nomoto (Kavli IPMU)

0-1. My research interests‐ Formation of dust in the ejecta of supernovae‐ Dynamics, destruction, and heating of dust grains
in high-velocity shock waves‐ Evolution of grain size distribution in galaxies andinterstellar extinction curves‐ Origin of dust grains in the early universe and theroles of dust in star formation‐ Formation of dust in stellar winds and mass-loss
history at late phases of stellar evolution

0-2. 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 (e.g., Nozawa et al. 2003, 2007)

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–S
atlayer~1-3 years
afterlayer
explosion
Fe–Ni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. Herschel detects cool dust in SN 1987A~180K~10-5 Msun

~20K
~0.5 Msun
Matsuura+2011

on 4 Oct 2003
Gemini T-ReCS(λ = 10.36 μm)
2 pixels : 0.18”(Bouchet+04)

Herschel detects cool (~20K)
dust of ~0.4-0.7 Msun toward
SN 1987A!

1-3. 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 !!

1-4. 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

1-5. ALMA reveals dust formed in SN 1987A
SED of 25-years old SN 1987A
blue: Hαgreen: 1.6 µm
red: CO(2-1)➜ >0.1 Msunof CO

Indebetouw+2014

ALMA spatially resolves cool(~20K) dust of ~0.5 M sun formedin the ejecta of SN 1987A➔ SNe could be production
factories of dust grains

1-6. Possible target: SNR 1E0102-72.3 in SMC
young (compact) supernova remnants in LMC/SMC !
・ SNR 1E0102-72.3

24 μm

X-ray, radio- O-rich (Type Ib?)
- age : ~1000 yr- Mwarm ~ 10-3 Msun
- Mcool ~ ???
Stanimirovic+05

・ Cassiopeia A

24 μm

Gaetz+00
100 μm- O-rich (Type IIb)
- age : 330 yr- Mwarm < 10-2 Msun
- Mcool ~ 0.07 Msun
Cas A model (Nozawa+10)

Barlow+10, A&A, 518, L138

1-7. SNR 1E0102-72.3 is too extended!
Band 3 with ACA
Band 3

Band 9 with ACA

SN 1987A

40 arcsec

1-8. Flux estimates necessary for detection
1987ABand 9

1E0102
Band 9full operation
1 sigma, 1 hr

effective flux(flux per beam)

1-9. Summary of observations of SN dust
‐ALMA confirmed the presence of huge amounts of
newly formed dust in the ejecta of SN 1987A➜ heavy elements (Si, Mg, Fe, C) are locked up in dust grains➜ SNe are main production factories of dust grains‐ It seems too hard to detect thermal emission fromcool dust in any other SNe/SNRs with ALMA
➜ young SNRs in LMC/SMC are too extended‐A part of dust grains formed in the SN ejecta will be
destroyed by the reverse shocks
what fraction of dust grains can survive to be injected?
➜ destruction efficiency depends on dust composition and size
➜ infrared to submm observations have few information on thethe composition and size distribution of dust

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

He coreFSRSCD2. Theoretical Studies on Dust
Formation in SNe2-1. Dust formation in primordial SNe
Nozawa+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

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

0.01 μm

C / O < 1 ➔ all C atoms are locked up in CO
C / O > 1 ➔ all O atoms are locked up in CO
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

2-3. 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

2-4. 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2-5. Temperature and density of gas in SNRs
Nozawa+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

2-6. 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

2-7. Dust mass and size ejected from SN II-PPISNe
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2-8. Summary of dust production in 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
➔ making significant contribution to dust budget