2012/11/06

Dust Synthesis in Supernovae
and Reprocessing in Supernova
Remnants
Takaya Nozawa
Kavli IPMU (Kavli Institute for the Physics andMathematics of the Universe)
Collaborators;
T. Kozasa, A. Habe (Hokkaido University)
K. Maeda, K. Nomoto (K-IPMU)
H. Umeda (U.T.), N. Tominaga (Konan Univ.)

1. Summary of observed dust mass in CCSNe
SN1987A
CrabtheoryCas A
missing cold dust?

young SNRs

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

FIR to sub-mm observations have revealed the presenceof massive (>0.1 Msun) dust grains in the ejecta of CCSNe

1. Summary of observed dust mass in CCSNe
SN1987A
CrabtheoryCas A
missing cold dust?

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 mass of the newly formed grains can survive to be
injected into the interstellar space?

2. Dust Synthesis 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. Total mass of dust formed
Nozawa+03, ApJ, 598, 785
SNe II-P (Z=0)
SNe II-P (Z=0)

Total dust mass increases
with increasing Mpr
Mdust = 0.1-1.5 Msun
➔ almost all Mg, Si, and Fe
are locked in dust
(also, cf. Raffaella’s talk)・ depletion factor
fdep (Mdust/Mmetal) = 0.2-0.3
cf. fdep = 0.4-0.5 in the MW➔ incorporation of C and O
into dust in MCs needed?

2-2. Average radius of dust formed
Nozawa+10, ApJ, 713, 356
SN II-P (Mpr=20 Msun)

SN IIb (Mpr=18 Msun)

0.01 μm

0.01 μm

・ SN II-P with massive H-env➔ adust > 0.01 μm

・ SN IIb w/o massive H-env➔ adust < 0.01 μm

・ Mdust =0.1-1 Msun

・ Mdust = 0.167 Msun

The sizes of newly formed dust depend on the SN types
and are smaller in less massive-envelope SNe2-3. Classical nucleation theory
・ classical nucleation theory－ sticking coefficient?
➔ usually sn = 1

・ chemical approach➔ Isabelle’s talk－ cluster temperature?
➔ Tclus = Tgas

・ kinetic approach➔ Davide’s talk－ surface energy of small clusters?
➔ same as the bulk
－ shape of small clusters? ➔ sphere－ the steady-state nucleation cannot be applied in
rarefied astrophysical environments(e.g., Donn & Nuth 1985; Stefan’s talk; Isabelle’s talk)## molecular formation? (cf. Claes’s talk)➔ complete formation of CO and SiO molecules

2-4. Concept of nucleation theoryc1c(2)J2c(3)

J3

αn-1c1cn-1 c(n)
Jn

βncn

・ master equations

sn = 1

2-5. Non-steady-state nucleation
・ steady-state nucleation rate: Js➔ assuming Js = J2 = J3 = ・・・ = J∞

μ = 4πa02σ / kT
(σ = 1400 erg cm-2 for bulk C )・ non-steady-state nucleationn＊= 100

2-6. Steady vs. Non-steady (1)c10 = 108 cm-3

c10 = 107 cm-3・ dashed line : steady-state nucleation
・ dotted line : non-steady-state nucleation

The difference between steady and non-steady
nucleation is small for higher initial densities

2-7. Steady vs. Non-steady (2)c10 = 106 cm-3

c10 = 105 cm-3・ dashed line : steady-state nucleation
・ dotted line : non-steady-state nucleation

The difference between steady and non-steadyseems significant for lower densities

2-8. Steady vs. Non-steady: size distribution
Nozawa & Kozasa in prep.

The size distribution of
bulk grains from nonsteady-state is consistent
with that from steady-statenc ~ 1-2

n＊ = 100

2-9. Steady and non-steady・ steady-state nucleation rate: Js
gas atoms

nc (= 1-104)

bulk dust

・ non-steady-state nucleation rate: J＊
gas atoms

clusters

n＊= 100nc (= 1-104)

bulk dust

2-10. Effects of microphysics on dust formation
0.05

Carbon mass in SNe II-P

Fallest, TN,+2011, MNRAS, 418, 571

Mass of C grains formed is
not sensitive to sticking
coefficient and cluster shape
Size distribution of carbon grains
spherical

aspherical

0.032
0.01 μm

2-11. No formation of SiC in the calculations
Nozawa+11, ApJ, 736, 45

SN Ia

Mdust ~ 0.1 Msun
with sn = 1
The earlier formation of C
grains necessarily prevents
condensation of SiC

Formation of C dust in AGB
is suppressed by radiation(e.g., Yasuda & Kozasa 2012)

M(56Ni) in SNe Ia ~ 0.6 Msun
➔ much stronger radiation
fields may prevent thecondensation of dust
(cf. Rubina’s talk, Davide’s talk)3. Reprocessing of Dust in SNRs
T = (1-2)x104 K
nH,0 = 0.1-1 cm-3

He coreFSRSCD

3-1. Erosion rate of dust by sputtering
Nozawa+06, ApJ, 648, 435

projectile: H+ + He+

projectiles: O+・ erosion rate at T > 106 K:
da/dt ~ 10-6 nH μm yr-1 cm3・ destruction timescale by sputtering:τsput ~ 106 yr (1 cm-3/nH) (a/1.0 μm) yr

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3-4. 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
Msunnewlyformed
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

3-5. Fates of large grains ejected from CCSNe
100 pcFor nH < 0.1 /cc, large grains(> 0.1 µm) ejected from SNe
can travel more than 100 pc➔ transporting metals anddust to the intergalactic
medium3-6. Mixing of metals in MCs via dust

The segregated motion oflarge grains (> 0.1 μm) fromthe gas can carry metals
efficiently deep inside themolecular clouds with thesize of ~1-10 pc

4. Summary of this talk・ Size of newly formed dust depends on types of SNe－ H-retaining SNe (Type II-P) : aave > 0.01 μm➔ may be important producers of interstellar dust
－ H-stripped SNe (Type IIb/Ib/Ic and Ia) : aave < 0.01 μm➔ may be poor producers of interstellar dust
(dust is almost completely destroyed in the SNRs)

・ radiative effects on small clusters may be the mostimportant factor for dust formation in SNe－ sticking coefficient and cluster shape affect the size of newly
formed grains－ steady-state approximation is accetable in nucleation theory

・ Large grains ejected from SNe may play a critical rolein the metal enrichment of MCs and IGM➔ It should be considered how dust grains from SNe (and AGBstars) are distributed into the ISM