Masayuki Yamanaka ( Kyoto Univ. )

1. Follow-up Observations of Supernovae using Optical & NIR telescopes Masayuki Yamanaka(Kyoto Univ.) SN & SNR 2012 @ Mitaka/NAOJ, 2012, Oct. 15 - 17

2. 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 !

3. in 21th in 20th Luminous Ic 07bi-like Hybrid Ia-IIn Luminous Type IIL 02cx-like Revised version of Turatto+ 2007

4. You can see a“SN”in a beatiful galaxy using your eye Extragalactic (<100Mpc) : Point source CC Ia Composited byRyosukeItoh

5. 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。

6. Weather Problems 2012 Oct. 18 2012 Oct. 17

7. Altitudes of OISTER Targets

8. What we can see in optical and NIR observations ? Spectrum Light Curve ~a few weeks > 100-200d ~a few weeks 56Ni(6.07d) emission emission 56Co(~77d) P Cyg profile Late-phase ( > 100-200d ) absorption ~a few weeks > 100-200d Outer layer Timescales of Light Curve ～ 56Ni or 56Co decay ～ 56Ni mass, Mej, EK -> progenitor mass Photosphere receision Si, S, Ca etc. (for SNeIa) thin thick Photosphere Spectra → Line velocity Free-expandsv ∝ r → line velocity -> structure → explosion mecanism 56Ni → 56Co → 56Fe γ γ

9. Methods Direct 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)

10. Today’s Topics Faint Type IIL SN 2010gi : Low-mass ejecta ? (Okushima, Kawabata, et al. in prep) Extremely Luminous Type IaSN 2009dc : Super-Chandrasekhar SN ? (Yamanaka, et al. 2009, Yamanaka et al. in prerp)

11. CC SNe : Diversity from outer layer Type IIn Type Ic H H He outer layer +wind(H > 5M◎) O, C, Ne progenitor mass M > 5M◎ O, Ne Mg H Ejecta interact with CSM Fe Type Ib Type IIL H Progenitor mass M > 2.5M◎ (H ~ 2-3M◎ ) H more stripped-envelope ✓ initial mass ✓ binarity ✓ rapidly-rotation →Diversity H H Type IIb (H < 1M◎ ) Nomoto et al. 1996

12. SN 2010gi (Type IIborIIL ?) Okushima, Kawabata, et al. in prep Discovered at 2010/07/18.51(UT) Z=0.004146 (~20Mpc) Box-liked profile in H-alpha : peculiar ? Spectra exhibit both H and H : Type IIb? Recent survey ・faint galaxy = low metal ? host : IC 4660 (Lower metallicity than SNeIb/c) At least, SN 2010gi woud be a more-stripped envelope SN

13. Template Subtraction Method SN contaminated by host Hosttemplate ✔ The focus of the PSF scaled to that of template

14. I – 2.4 R－1.2 V B + 1.2 BVRcIc-band Light Curves Faster decline than other IIb/Ib/IcSNe . The decline rateafter 30 days was inconsistent with that from 56Co decay Very slowly rising (shock breakout ?) These are inconsistent with that Type IIb!

15. Light curve comparing with Type IIL Faster decline than other Type IIL The light curve shape is comparable of that of SN 1980K? First event that exhibits slowly-rising phase?

16. Discussion (progenitor) We estimated the 56Ni and ejected mass from luminosity and timescale. The progenitor mass would be lower than that of SN 1993J Is the progenitor system binary?

18. Type Ia SN : distance indicator Single Degenerate ? More luminou Double Degenerate Altavilla et al. 2004 Slower decline ✔ More luminous events are more slowly fading ✔ Well reproduced by the hydrodynamial “Chandrasekhar model” ⇒ However、progenitor(SD or DD)& explosion model (Defralgrationv.s. Delayed Detonation)remain unresolved problem.

19. SuperNova2009dc Discovered at 16.5 mag on Apr. 9.31(ＵＴ). Distance89.3Mpc UGC 10064(CBET 1762) Spectroscopy at Apr.16 Similar to super-Chandrasekhar SN Ia. Show the CII absorption (CBET1768)。 Really Super-Chandrasekhar SNe ? Closer than other super-Chandrasekhar event

20. Optical Light Curves ⊿m15(B): magnitude difference between the peak and 15 days after its peak. 03fg 06gz ● 09dc ×06gz － 05cf Very slow decline Ic Rc V B 09dc(0.65) Decline rate indicates the luminosity ⇒SN 2009dc is expected to be intrinsically extremely luminous

21. Absolute magnitude 03fg Corrections of host extinction ⇒ intrinsic luminosity 06gz Galaxy host 09dc(0.65) 06gz:Mv=-19.90+/-0.21 If we ignore the extinction, SN 2009dc is one of the most luminous Type Ia SN.

22. Quasi-Bolometric luminosity and 56Ni mass ● 09dc(吸収あり) Assumption：optical flux is 60%.of total(c.f.Stritzinger et al. 2006) Rising-time is 23 day (Silverman et al. 2010) ×09dc(吸収なし) ― 06gz -- 05cf 56Ni mass is strongly related to the luminosity Yamanaka et al. 2009 No extinction: 56Ni mass is estimated to be 1.3 +/- 0.3 M8 Extinction : 2.0+/- 0.5 M8 c.f. typical SN 2005cf : 0.8M8 Ever largest 56Ni mass in SNeIa

23. Light curves fitting model Basical model; Arnett (1982) 09dc 06gz 03du Decay time 56Ni 8.8 day 56Co 113.5 day Estimatedthe MejandEK 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 ) We can explain the light curves in its early phase

24. Spectra: remarkable CII SN 2009dc C Typical SN Ia Ni,Fe Ni,Fe Yamanaka et al. 2009 CII is see until 5.6d ⇒very thick C layer C : direct origin of WD ⇒ very massive WD Si,S,Ca

25. Structure of ejecta Carbon (unburnt material) Si,S,Ca,etc (burnt material) Ni(Fe) CO CO CO Ni(Fe) Ni(Fe) normal 06gz 09dc 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 2009dccould be a Super-Chandrasekhar SN!

26. Late-phase Obs.Yamanaka et al. 2013, in prep

27. Motivations of late-phase As ejecta expands, it will be more optically-thin. Light Curves 56Co decay → 56Ni mass Independly estimate its mass Spectra emission line ⇒We can see the inner-structure Doppler shift : Distribution of in ner-ejecta elements

28. Late-phase Light Curves More fading in the optical than those of Typical SN 2003du. Become redder color SED is dominated in NIR region

29. Quasi-bolometric luminosity Similar to absolute luminosity of 03du Fading is real! ⇒ dust formation ??

30. Late-phase Spectrum : ID of [Ca II] SN 2009dc Ni(Fe) Ca in inner region ⇒strongly mixing Fe, Ni [Fe II]λ 7155、[NiII]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?? Unseen in Typical SN Late-phase spectra of SN 2006gz ⇒SN 2009dcでは明らかに確認できた

31. Summary Carbon (unburn material) Early-phase Late-phase Si,S,Ca,etc (burnt material) Dust?? Fe,Ni Fe,Ni Ni(Fe) Ni(Fe) Dust?? CO CO Dust?? normal Ca?? SN 2009dc SN 2009dc will be reproduced by massive white dwarf (see Kamiya-san’s poster)

32. Open Question 1. Explosion model Ropke+ 2007 Kasen+ 2009, Nature 遅延爆轟波 爆燃波 ✓ 熱源の56Niを大量生成　 ✓ 層状構造をつくる ✓暗い光度を予言 ✓全体的にmixing 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。

33. Open Question 2. progenitor candidate Rapidly-rotating Merger Pakmor+ 2010 Pfannes+ 2010 ⇒ 56Ni mass ~ 0.1M、 total mass ~1.9M ⇒ 56Ni mass ~ 1.5M、 total mass ~2.1M SN 2009dc 56Ni mass ~ 2.0M, 2.4M Faint Type SN Iais well reproduced (Pakmor+)

34. 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!