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 ?

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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!