2013/05/24

Mid-infrared Observationsof Aged Dusty Supernovae
Takaya Nozawa （野沢 貴也）(Kavli IPMU, University of Tokyo)
special thanks: Tanaka, M., Arimatsu, K.,
Ohsawa, R., Sakon, I.

1-1. Origin of IR emission from SNe
Dust formation in the ejecta

Dust formation in dense shell

IR light echo by CS dust

Shock heating of CS dust

1-2. 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

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

1-3. Observing SNe in nearby galaxies
SNe are important sources of interstellar dust?
○ Unresolved problems ofdust formation in SNe

MIMIZUKU
imaging, 10^4sec, 5σ－ what is the cause of difference indust mass observed in MIR/FIR?
－ when does dust start to form?

silicate－ what is the main compositionof newly formed dust?
－ what is a typical size of dust?
－ what fraction of SNe forms dust?
・ recent unobserved SNe in MIR－ SN 2011dh (M51, d = 8.1 Mpc)
－ SN 2011fe (M101, d = 6.7 Mpc)

carbon

SN 2004et (d=5.6 Mpc, Kotak+09)
Mdust ~ 10-4 Msun, Tdust ~ 650K

2. Observing CS dust in aged dusty SNeSN1987A

FIR observations

CrabCas A

newly formed
dust in ejecta

shock-heated
CS dustshock-heated IS dustby courtesy of M. Tanaka

Exploring the evolution of CS dust by MIR observationsof SNe 5-100 yr after explosions with MIMIZUKU

3-1. Promising targets (1): SN 1987A○ SN 1987A (Type II-pec)－ host galaxy: LMC (d = 50 kpc, southern sky)
－ interacting equatorial ring

－ ring diameter : 2” (= 0.5 pc @ 50 kpc)
IR-mm SED of 23-years old SN 1987A

2 arcsec
on 2009 Apr (Larsson+11)

Matsuura+11

on 1994 Feb (Burrow+95)

3-2. Properties of CS dust around SN 1987A
IR light curve

MIR SEDs

Spitzer observation, Dwek+10

・ IR fluxes increase in
all bands by a factorof ~3 between 17 yr
and 22 yr
・ properties of CS
dust in ERsilicate
Tdust = 180 K
Mdust =10-6-10-5 Msun
LIR = 1036-1037 erg/s(Seok+08, Dwek+08)

Dwek+08・ grain radius:a = 0.02-0.2 μm➔ relatively large

3-3. Expected IR images of SN 1987A
on 4 Oct 2003
Gemini T-ReCS(λ = 10.36 μm)
2 pixels : 0.18”(Bouchet+04)

SN1987A with MIMIZUKU－ spatially resolving
equatorial ring
－ multi-epoch ➔evolution of CS dust
－ MIR flux: 10-100 mJy

AKARI
24 μm
(Seok+08)

On 6 Jan and 1 Feb 2005 (Bouchet+06)

Chandra imagePark+07

4. Promising targets (2): SN 1993J○ SN 1993J (Type IIb)
－ host galaxy: M81 (d = 3.6 Mpc, northern sky)
－ L band excess at >130 day (Matthews+02)－ strong interaction with CSM (Weiler+07; Chandra+09)
AKARI images at 13 yr post explosion

AKARI detected MIRemission from 1993J
What is the origin ofIR emission?
・ shock-heated dust
・ newly formed dust・ IR light echo
Arimatsu, TN, et al. in prep.

5-1. Promising targets (3): SN 1978K○ SN 1978K (Type IIn)
－ host galaxy: NGC 1313 (d = 4.1 Mpc, southern sky)
－ X-ray luminous (Smith+07) ➔ massive CSM
AKARI images at 28 yr post explosion

Tanaka, TN, et al. (2012)

silicate
Tdust=230K, Mdust ~10-3Msun
LIR ~ 1.5x1039 erg/s

5-2. Origin of MIR emission from SN 1978K○ MIR emission from SN 1978K－ IR luminous: LIR = 1.5x1039 erg/s➔ ruling out emission of newly formed dust and IR echo

－ thermal emission from shock-heated CS dust

large initial radius of CS dust;a0 ~ 0.3 μm (Tanaka+12)

Multi-epoch IR observationsof aged SNe are essential !!

6-1. MIR observations of other aged dusty SNe○ SN 1980K (Type II-L)－ host galaxy: NGC 6946
(d = 5.6 Mpc, northern sky)

－ Tdust = 200 K, Mdust ~ 10-4 Msun
(LIR ~ 1038 erg/s)－ IR echo by IS dust (Sugerman+12)○ SN 1995N (Type IIn)
－ host galaxy: Arp 261(d = 24 Mpc, southern sky)

－ Tdust = 240 K, Mdust ~ 0.1 Msun
(LIR ~ 7.7x1040 erg/s)－ CS dust heated by radiationfrom shocked region (van Dyk 2013)

6-2. Other possible targets
d = 5 Mpc
in addition to SN 1987A (II-pec),
SN 1993J (IIb), SN 1978K (IIn),
SN 1980K (II-L), SN 1995N (IIn)

MIMIZUKU
imaging, 10^4sec, 5σ○ nearby Type IIn SNe－ SN 1998S (IIn) (d = 17 Mpc)
(Pozzo+04)－ SN 2005ip (IIn) (d = 30 Mpc)
(Fox+11, 12)〇 very nearby Type II-P SNe

Tanaka, TN, et al. (2012)－ SN 2002hh (II-P) (d = 5.6 Mpc)
(Barlow+05)－ SN 2004et (II-P) (d = 5.6 Mpc)
(Kotak+09, Fabbri+11)－ SN 2004dj (II-P) (d = 3.5 Mpc)
(Szalai+11, Meikle+11)

IR echo?
SN 2004et (Kotak+09)

7. Promising targets (3): NGC 300OT○ NGC 300OT (SN imposter)－ host galaxy: NGC 300 (d = 1.9 Mpc, southern sky)
－ IR luminous ➔ eruption of dust-enshrouded star~100 day

opt/IR SED of the progenitor

carbonTdust = 400K
Mdust ~10-4Msun
LIR ~ 2x1039 erg/s
Prieto+09

Berger+09

400-600 day
Ohsawa+10

Dust formation
Tdust = 600-800K
Mdust > 10-5Msun
LIR ~ 1039 erg/s

8. Summary〇 Dust formation in SNe (t = 1-3 yr, d < 5 Mpc)
－ formation time, composition, and mass of dust
－ what fraction and what type of SNe produce dust?

〇 CS dust in aged SNe (t = 5-30 yr, d ~ 5 Mpc)
－ dust formation condition in stellar winds－ dust mass and temperature ➔ gas density, dust size
－ mass-loss history of the progenitor stars➔ diversity of SN types, evolution of massive stars〇 Dust-enshrouded optical transients (d ~ 2 Mpc)
－ Effect on UV/opt light curves, or hidden SNe?