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Follow-up Observations of Supernovae using Optical & NIR telescopes. Masayuki Yamanaka ( Kyoto Univ. ). SN & SNR 2012 @ Mitaka /NAOJ, 2012, Oct. 15 - 17. Some themes in“SN & SNR 2012” (would be related to “optical & NIR observations”). How much (the minimum) mass the progenitor ? - PowerPoint PPT Presentation
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Masayuki Yamanaka (Kyoto Univ.)
Follow-up Observations of Supernovae using Optical & NIR telescopes
SN & SNR 2012 @ Mitaka/NAOJ, 2012, Oct. 15 - 17
Some themes in“SN & SNR 2012”(would be related to “optical & NIR observations”)
How much (the minimum) mass the progenitor ?Do a SN really explodes in the simulation ? (CC)-> Aspherical structure ? -> Elements distribution in the ejecta ? Did CSM wind form the cavity ? (Local environment ? Host properties ?)The progenitor-systems are “double” or “single” ? (Ia)
Key word is “Diversity” for optical & NIR observations !
Revised version of Turatto+ 2007
in 20thin 21th
02cx-like
Hybrid Ia-IIn
Luminous Ic07bi-like
Luminous Type IIL
You can see a“SN”in a beatiful galaxy using your eye
Composited by Ryosuke Itoh
Extragalactic (<100Mpc) :Point source
Ia CC
Recent Activity in Japan光赤外線大学間連携事業 (OISTER)
日本国内の中小口径望遠鏡を持つ観測所・大学の研究教育の協同体制 (2011 年発足 )現場レベルでの有機的な共同・連携観測 ⇒ 多様なタイムスケールの変動天体を柔軟に観測研究できるポテンシャルを有する。
Weather Problems
2012 Oct. 17
2012 Oct. 18
Altitudes of OISTER Targets
What we can see in optical and NIR observations ?
thickthin
Light Curve
~a few weeks
Late-phase ( > 100-200d )
~a few weeks > 100-200d
~a few weeks > 100-200d
absorption
emissionemission
56Ni (6.07d)
56Co(~77d)
56Ni → 56Co → 56Fe γ γ
Si, S, Ca etc. (for SNe Ia)
Spectra → Line velocity Free-expands v r∝→ line velocity -> structure→ explosion mecanism
Timescales of Light Curve~ 56Ni or 56Co decay~ 56Ni mass, Mej, EK
-> progenitor mass
Outer layerPhotosphere
receision
Spectrum
P Cyg profile
Photosphere
MethodsDirect comparison the light curves, color, spectra, line velocity with those of other SNe
Estimated the 56Ni mass from peak luminosity (with distance)
Estimated the ejected mass and kinetic energy from quasi-bolometric light curves (and ejecta velocity), based on Arnett (1982)
Today’s Topics
Faint Type IIL SN 2010gi : Low-mass ejecta ?
(Okushima, Kawabata, et al. in prep)
Extremely Luminous Type Ia SN 2009dc : Super-Chandrasekhar SN ?
(Yamanaka, et al. 2009, Yamanaka et al. in prerp)
CC SNe : Diversity from outer layer
Fe
O, Ne Mg
He Houter layer +wind (H > 5M◎)
O, C, NeH
H
Type Ib
Type IIn
H
H
Type IIL(H ~ 2-3M ◎ )
H
H
Type IIb
Ejecta interact with CSM
Type Ic
(H < 1M ◎ )
Progenitor massM > 2.5M◎
Nomoto et al. 1996
progenitor massM > 5M ◎
more stripped-envelope
✓ initial mass ✓ binarity ✓ rapidly-rotation
→Diversity
SN 2010gi (Type IIb orIIL ? )
Spectra exhibit both H and H : Type IIb?
At least, SN 2010gi woud be a more-stripped envelope SN
Discovered at 2010/07/18.51(UT)Z=0.004146 (~20Mpc)
Recent survey・ faint galaxy = low metal ?host : IC 4660 (Lower metallicity than SNe Ib/c)
Okushima, Kawabata, et al. in prep
Box-liked profile in H-alpha : peculiar ?
Template Subtraction Method
SN contaminated by host Host template
✔ The focus of the PSF scaled to that of template
BVRcIc-band Light Curves
B + 1.2
V
R - 1.2
I – 2.4
Faster decline than other IIb/Ib/Ic SNe .
The decline rate after 30 days was inconsistent with that from 56Co decay
Very slowly rising (shock breakout ?)
These are inconsistent with that Type IIb !
Light curve comparing with Type IIL
Faster decline than other Type IILThe light curve shape is comparable of that of SN 1980K?
First event that exhibits slowly-rising phase?
Discussion (progenitor)We estimated the 56Ni and ejected mass from luminosity and timescale.
Is the progenitor system binary?
SN 1993J SN 2010giMNi(M◎)
0.08(Shigeyama et al.
1994)
0.014-0.021
Mej(M◎)
1.9-3.5(Young et al. 1995)
1.2-2.6
The progenitor mass would be lower than that of SN 1993J
Type Ia SN : distance indicator
✔ More luminous events are more slowly fading ✔Well reproduced by the hydrodynamial “Chandrasekhar model”
Mor
e lu
min
ouSlower decline
Altavilla et al. 2004
⇒ However 、 progenitor(SD or DD) & explosion model (Defralgration v.s. Delayed Detonation) remain unresolved problem.
SingleDegenerate
DoubleDegenerate
?
SuperNova 2009dcDiscovered at 16.5 mag on Apr. 9.31( UT ). Distance 89.3Mpc UGC 10064 (CBET 1762)
Spectroscopy at Apr.16Similar to super-Chandrasekhar SN Ia.Show the CII absorption (CBET 1768) 。Really Super-Chandrasekhar SNe ?
19
Closer than other super-Chandrasekhar event
Decline rate indicates the luminosity⇒SN 2009dc is expected to be intrinsically extremely luminous
Very slow decline● 09dc× 06gz- 05cf
B
V
Rc
Ic
⊿m15(B) : magnitude difference between the peak and 15 days after its peak.
Optical Light Curves
ID ⊿m15(B)SN 2009dc 0.65+/-0.03SN 2006gz 0.69+/-0.05sN 2005cf 1.05
20
09dc(0.65)
03fg06gz
Abs. MvNo -19.90+/-0.05Yes -20.32+/-0.19
06gz : Mv=-19.90+/-0.21 If we ignore the
extinction,SN 2009dc is one of the most luminous Type Ia SN.
Galaxy
host09dc(0.65)
Corrections of host extinction ⇒ intrinsic luminosity
Absolute magnitude06gz
03fg
● 09dc( 吸収あり )× 09dc( 吸収なし ) ― 06gz-- 05cf
Assumption : optical flux is 60%.of total (c.f.Stritzinger et al. 2006)Rising-time is 23 day (Silverman et al. 2010)
No extinction : 56Ni mass is estimated to be 1.3 +/- 0.3 M8Extinction : 2.0+/- 0.5 M8 c.f. typical SN 2005cf : 0.8 M8
Ever largest 56Ni mass in SNe Ia
Yamanaka et al. 200956Ni mass is strongly related to the luminosity
Quasi-Bolometric luminosity and 56Ni mass
Test for SN 2003du (Mni =0.7M 、 Mej=1.4M 、 EK=1.3E51 erg )SN 2009dc (Mni =2.0M 、 Mej=2.4M 、 EK=1.9E51 erg )
09dc03du 06gz
Basical model; Arnett (1982)
Decay time 56Ni 8.8 day 56Co 113.5 day
Estimated the Mej and EK
We can explain the light curves in its early phase23
Light curves fitting model
Yamanaka et al. 2009
超新星 phaseSN 2009dc 5.6d after maxSN 2006gz 11d before max
SN 2003du (typical) unseen
CII is see until 5.6d⇒very thick C layerC : direct origin of WD
⇒ very massive WD
Spectra : remarkable CII
Typical SN Ia
Si,S,Ca
Ni,FeNi,Fe
CSN 2009dc
Extremely luminous 、 very slow light curves : rich 56Ni(Fe) layer
Low polarization : almostly spherical symmetry (Tanaka et al.)Deep absorption of CII : thick C layer
⇒very massive WD (c.f. 2.4M8 in standard model)⇒SN 2009dc could be a Super-
Chandrasekhar SN !
CO CO CONi(Fe) Ni(Fe) Ni(Fe)
Si,S,Ca,etc(burnt material)
Carbon(unburnt material)
normal 06gz 09dc
25
Structure of ejecta
Late-phase Obs.Yamanaka et al. 2013, in prep
26
Motivations of late-phaseAs ejecta expands, it will be more optically-thin.
Light Curves56Co decay → 56Ni massIndependly estimate its mass
Spectraemission line ⇒We can see the inner-structure Doppler shift : Distribution of in ner-ejecta elements 27
More fading in the optical than those of Typical SN 2003du.
Become redder color
28
SED is dominated in NIR region
Late-phase Light Curves
Similar to absolute luminosity of 03du
⇒ dust formation ??
Fading is real!
29
Quasi-bolometric luminosity
Ni(Fe)
SN 2009dc
Fe, Ni
Late-phase Spectrum : ID of [Ca II]
[Fe II]λ 7155 、 [Ni II]λ 7378 : -600 km s-1 [Ca II] λ 7299 +300 km s-1
⇒ Ca would be distributed in inner region than that of Fe
Ca??
Ca in inner region⇒strongly mixing
Unseen in Typical SN
Late-phase spectra of SN 2006gz ⇒SN 2009dcでは明らかに確認できた
Summary
SN 2009dc will be reproduced by massive white dwarf(see Kamiya-san’s poster)
31
Early-phaseLate-phase
CO CONi(Fe) Ni(Fe)
Si,S,Ca,etc(burnt material)
Carbon(unburn material)
normalSN 2009dc
Ca??
Fe,NiFe,NiDust??
Dust??
Dust??
Kasen+ 2009, Nature
爆燃波 遅延爆轟波 Ropke+ 2007
✓ 暗い光度を予言✓ 全体的に mixing✓ 熱源の 56Ni を大量生成 ✓ 層状構造をつくる
32
Open Question 1. Explosion model
両者の爆発が上手くバランスする? ( このような理論モデルは無い。 ) あるいはまったく新しい爆発モデルが必要か。
Open Question 2. progenitor candidate
Rapidly-rotating Merger
⇒ 56Ni mass ~ 1.5M 、 total mass ~2.1M
Pfannes+ 2010
Pakmor+ 2010
⇒ 56Ni mass ~ 0.1M 、 total mass ~1.9M
SN 2009dc56Ni mass ~ 2.0M, 2.4M
Faint Type SN Ia is well reproduced (Pakmor+)
SUMMARY Extremely-Luminous SN 2009dc could be a
super-Chandrasekhar candidate!
Low-luminous Type IIL SN 2010gi originated from the low-mass progenitor
Optical & NIR observations using 1-2m class telescope can uncover the diverisity!