2013/10/22

Probing Dust Formation Processin SN 1987A with ALMA
Takaya Nozawa (Kavli IPMU)
andMasaomi Tanaka (NAOJ)

1-1. Introduction
SNe are important sources of interstellar dust?
－ 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 be ejected toexplain such massive dust at high-z (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 (Nozawa et al. 2003; 2007)

What composition, size, and mass of dust
can be formed in SNe?

1-2. Herschel detects cool dust in SN 1987A
SED of 23-years old SN 1987A

Matsuura+11

Herschel detects cool (~20K)
dust of ~0.4-0.7 Msun toward
SN 1987A!
➔ SNe may be production
factories of dust grains

1-3. Summary of observed dust mass in CCSNe
SN1987A
Crabtheory
Cas A
missing cold dust?
optically thick clumps?

by courtesy of M. Tanaka

what is a cause of difference b/w warm/cool dust mass?
when and where are dust grains formed in SN 1987A?

1-4. Why SN 1987A with ALMA?
SN 1987A is the best target to detect cool dust

・ SN 1987A (➔ dust formation has been confirmed)‐nearest SN ever observed (in LMC)
‐young (~27 yr) and compact (~2” in diameter)‐well studied object at multi-wavelengths
・ other candidates‐extragalactic SNe ➔ too distant (too faint)‐Galactic SNRs ➔ too old (too extended)
SN 1987A is the only target to detect cool dust

1-5. Young Type Ib SNR 1E0102-72.3 in SMC
Band 3 with ACA@Cycle1

SNR 1E0102in SMC(age: ~1000 yr)➔ known as acousin of CasA

Band 9 with ACA@Cycle1

SN 1987A

40 arcsec

2-1. 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 !!

2-2. Successful ALMA proposals for SN 1987A

This proposal was ranked
in the highest priority !!

Our proposal was
not executedBand 9extended configuration

Band 3, 6, 7, 9
compact configuration

2-3. Our proposal for ALMA Cycle 1
ALMA Cycle 1 Proposal‘Detecting cool dust in SN1987A’（Tanaka, TN, et al.)This proposal was notranked as high priority

Observing with the resolutionof 0.25” in Bands 7 and 9➔ 10σ detection for silicateof 0.1 Msun and 30 K

2-4. CO detection in SN 1987A with ALMA

Kamenetzky+13‐CO properties

blue: Hαgreen: [SiI]+[FeII] (1.64 µm)
red: CO(2-1)

Vco ~ 2200 km/s
Mco > 0.01 Msun
Tco > 14 K
fco = 0.025-0.141‐For ALMA full operation,
3D maps of CO and SiO

3-1. CO and SiO detection in SN 1987A
CO first overtone: 2.29-2.5 μm
CO fundamental: 4.65-6 μm
SiO fundamental: 7.6-9.5 μm

Evolution of CO mass

Liu+95‐CO emissions wereobserved during ~100600day after explosion‐CO mass in SN 1987A:
Mco ~ 4x10-3 Msun
Wooden+93

3-2. CO detection in Cassiopeia A SNR (1)SED of CO emitting knots‐CO mass in Cas A:
Mco ~ 10-6-10-5 Msunblue: Pβ
green: K band
red: CO(2-0)

Rho+09‐CO knots are within
the shocked ejecta➔ continuing molecularformation over 300 yr?

3-3. CO detection in Cassiopeia A SNR (2)AKARI IRC spectra‐CO mass and temperature
Mco ~ 6x10-7 Msun
Tco = 900-2400 K‐significant amounts of carbon
may have been locked up in CO‐CO is correlated to Ne ejecta andhas not been destroyed efficiently

Rho+12
Left panel
green: CO (4.5 μm)
red: dust (21 μm)
Right panel
green: Ne
red: Ar
blue: Si

3-4. CO detection in Cassiopeia A SNR (3)Herschel PACS

Wallstrom+13‐CO properties
Vco,ave ~ -2740 km/s
Mco ~ 5x10-6 Msun
Tco = 400 K and 2000 K
knot density: 106-7 /cm3
‐CO was dissociated by the shock,but has reformed recently

4-1. Probing CO molecules in SNRs
・ CO (and SiO) are confirmed in many Type II SNe/SNRs➔ CO (and SiO) molecules are considered to be
obstacles (precusors) for dust formation

・ CO (and SiO) line observations of SNRs with ALMA‐expansion velocity of the ejecta➔ elemental distribution and mixing in the ejecta‐temperature and density (column density) of CO➔ clues about clumpiness and clumpy factor‐estimated mass of CO➔ chemistry and environments in the ejecta➔ its effect on dust formation process

4-2. Searching for CO emission in SNR 1E0102?
Band 3 with ACA@Cycle1

SNR 1E0102
in SMC(age: ~1000 yr)

Band 3@Cycle1➔ known as acousin of CasA

SN 1987A

40 arcsec

4-3. Possible targets: young Ia SNRs in LMC
24 μm

HαX-ray0509-67.5(400 yr)‐Type Ia SNe‐age: ~500 yr‐radius: ~15”0519-69.0(600 yr)‐deflagration:
Borkowski+06

leaving unburned carbon‐detonation:
Mdust < 3x10-3 Msun・ shock-heated interstellar dust
➔ dust destruction by SNeburning most carbon

CO detection in SNe Ia➔ some hints about
explosion mechanism

4-4. Where is the companion star of SNR 0509?
SNR 0509-67.5 in LMC

There is left no possible
companion star in SNR
0509-67.5➔ This SN exploded as
double degenerate?
‐central region withthe radius of 2”➔ Vexp = 1200 km/s

‐formation of Fe grains(10-3 Msun) is expected(e.g., Nozawa+11)

Schaefer & Pagnotta+12

Is the companion star
hidden by Fe grains
formed in the ejecta?

4-5. Scaling relation of average grain radius
CMgSiO3

Λon: ratio of supersaturation timescale to gas collisiontimescale at the onset time of dust formation

Λon = τsat/τcoll ∝ τcool ngas
where τcool = ton / 3 (γ – 1)
Nozawa & Kozasa (2013)

5. Summary: possible science for ALMA Cycle2
・ Detecting dust and molecules in SN 1987A‐3D maps of dust emission in Band 7 and 9‐something using molecular lines?
➔ not much impressive in rivalry with EU/US group

we are seeking any other ideas and strategy!
・ Detecting CO in young SNRs in LMC and SMC‐searching for CO emission in Band 6, 7, and 9➔ it seems new and interesting even if not detected

we are seeking the collaborators who cantell us about observations of CO emission!

A-1. How dense is cool dust in 1E0102?
・ 1E0102.2-7219
R = 15 arcsec ➔ 1.3x1019 cm = 4.4 pc @ 60 kpc
what is the mass of dust if ISM dust is includedin the sphere with this radius?
Mdust ~ (4πR3 / 3) D (nH mH)= 0.077 Msun (D / 0.01) (nH / 1 cm-3)
・ Cassiopeia A
R = 100 arcsec ➔ 4.8x1018 cm = 1.6 pc @ 3.4 kpc

A-2. Importance of molecular lines in SN 1987A
・ CO and SiO molecules were detected around 300 days
after explosion in SN 1987A(CO and SiO were confirmed in many dust-forming SNe)・ Measuring the expansion velocity of the ejecta
・ CO molecule has been detected in Cas A SNR・ All condensible metals have to be tied up in dust grains
to explain 0.4-0.7 Msun of dust in SN 1987A➔ CO and SiO molecules can survive??

・ How much CO and SiO line fluxes can contribute thecontinuum flux?
➔ expected mass of CO and SiO: ~10-3 Msun

A-3. Summary of molecular lines
Band 3: 84-115 GHz
Band 6: 211-274 GHz
Band 7: 275-373 GHz
Band 9: 607-720 GHz

・ CO molecule・ SiO moleculeν=0, 1-0: 115.271 GHz (B3)ν=0, 2-1: 230.538 GHz (B6)ν=0, 3-2: 345.796 GHz (B7)ν=0, 4-3: 461.041 GHz
ν=0, 5-4: 576.268 GHz
ν=0, 6-5: 691.473 GHz (B9)ν=0, 2-1: 86.847 GHz (B3)ν=0, 3-2: 130.269 GHz
ν=0, 4-3: 173.688 GHz
ν=0, 5-4: 217.105 GHz (B6)ν=0, 6-5: 260.518 GHz (B6)ν=0, 7-6: 303.927 GHz (B7)ν=0, 8-7: 347.331 GHz (B7)ν=0, 15-14: 650.958 GHz (B9)ν=0, 16-15: 694.296 GHz (B9)