!"#$%&%'()*%+),#-."/(0)+1,-.%'"#,$%+)* 2%$3-,-4+)4()$0,$%+)-+) 56",$%+)-+7-.$,$(-859.:

Transcription

1 !"#$%&%'()*%+),#-."/(0)+1,-.%'"#,$%+)* 2%$3-,-4+)4()$0,$%+)-+) 56",$%+)-+7-.$,$(-859.: Kei Kotake!National Astronomical Observatory of Japan" Smith college, Northampton 18 th June 2011

2 The supernova shocks reach to the stellar surface!"#$%"&'(&)*%()*!(+),-(.("/( ($67(8 SN!"#$A Progenitor: %&Msun Before After!"#$%&'%()*+#%"*(',-#.*(%#/'%0'1/.*2-0%)3% explosion over these 40 years! (the supernova problem)

3 Neutrino heating mechanism Best-studied and most promising way to explode stars(> 10Msun).

4 Looking back 20+ Years of Modeling & Theory #Neutrino-heating mechanism spherical symmetry fails to explode massive stars with iron cores. Shock Radius VERTEX AGILE Oakledge ~20 years Sumiyoshi + 05 Shock stalls. (Liebendoefer et al. 2003) Doing-best simulations, but.. Time SN1987A 'CC SNe are generally aspherical. (Wang+.01,02) ' Multidimensional explosions are favorable for reproducing the synthesized elements. 9BC7C*C+)D-EF?(GC$HCD-1I?(J)/",)H)K!D-1F?GC$HCD1='A Multidimensional modeling is crucial!

5 2D neutrino-driven explosion (Garching): Marek and Janka (09) (Ray-by-Ray accurate Boltzmann transport) (15Ms by Woosley & Weaver (95) ) EOS table Based on liquid drop model Based on RMF(relativisitic mean field) + Thomas Fermi K(MeV) 'Nuclear experiment 240)20 Shlomo et al. (06) (T he first success of neutrino-driven exp. in 2D ( Weak explosion (~10^{50}erg) at the end of simulations. (1-2 orders of magnitude less than obs.) ( only for a softer EOS. (Accurate nuclear EOS!!) Average shock position

6 A la carte of recent 2D exploding models (!"#$%&'()*+"+$,-./0.123, 2+").45*6'*7 density v/c * F undamental problems remained! Suwa, Kotake, Takiwaki, Whitehouse, Liebendoefer, Sato (10) Time evolution of explosion energy Rotating high resolution Low resolutio n Non-rotating ( The obtained explosion energies are typically (Explosion energy becomes larger underpowered by 1or 2-orders-magnitudes ( Low-modes SASI-induced explosion for the rotating model. compared to observation (SN kinetic energy of erg). ( 8*()*+"+$,-./9.123,.2+") All of the exploding models 4:"6.!$%-;7 assume a very soft nuclear Yaknin EOS et al. (2010) (K=180 MeV).

7 Two representative E OSs in recent supernova simulations +LC**)#$6(M(N&$!*O<E0A incompressibility K = 180,220,375 MeV K = 281 MeV 9N%$,($*(C;((<E=A PQ,R"#S6$!!)T);)*O(C,H(!O##$*6O($,$67OU is a key ingredient for the supernova dynamics!

8 Impacts of E OSs in 1D models core bounce Smaller K (K=281 MeV) (The central density becomes higher for softer EOSs with smaller K. ( The symmetry energy is also pivotal to determine the postbounce evolution of supernova cores.

9 4/.#%2-%,)5'%)3%6-700'#,7%'*',879%: core bounce (Ye(# of electrons /# of baryons) becomes larger for the Shen EOS!"#!$"#%$&#'()'$%*++)!'*$),)'(*$-./$0)12$!"#,$345%$-6/$0)127

10 Dynamics near bounce Iron core = 1.4 Ms Inner core ~ 0.7 Ms (unshocked core) (The initial shock position is given ~ ( During the shock-passage in the iron core, the kinetic energy of the shock gets small due to the photo-dissociation at Mass outside the inner core ( Larger Ye leads to more massive inner core. ( Larger symm. energy can help to produce neutrino-driven explosions!

11 4/.#%2-%#/'%,)5'%)3%6;9%: Electron neutrino luminosity vs. postbounce time (Neutrino luminosity becomes higher with smaller compact to realize higher temperature inside.

12 Anti-electron neutrino luminosity vs. postbounce time Electron neutrino energy vs. postbounce time

13 To summarize the impacts of E OSs on SN dynamics Larger symmetry energy & Smaller incompressibility is the best combination to blow up massive stars! Demorest et al. Nature; Volume: 467,; Pages: 1081V1083 Final question is the symmetry energy! (As soon as you get the answer, let me know!) M ns

14 Our 2D model with K =180MeV LS E OS (15M sun progenitor by Woosley et al. (2002) (After bounce, the bounce shock stalls. Right panel is zoom up in the central region ( PN*C,H),7(WRR6$*)",(N%"R+ Q,!*CT);)*O(9NWNQAU()!("T!$6X$H Y(P;"&-#"H$!U("!R);;C*)",!( of the stalled shock ( The traveling timescales of matter in the neutrino-heated regions become longer due to non-radial oscillations. ( At around 300 ms after bounce, the neutrino-driven explosion sets in. Entropy per baryon (color)

15 2D model with SH E N E OS ( The SASI continues. but.we have not observed the shock-revival yet. ( This model seems not *"(T$($ZS;"H),7(' Q,(>[?()*<!(#"6$($C!)$6(*"("T*C),($ZS;"!)",!(*%C,(0[- (because the non-radial motions can elongate the neutrino-heating timescales) In 3D, one might expect a more favorable situation! (because matter can travel freely in the azimuthal9\a(h)6$r*)",8a

16 !"#$%&'()&#*+),#-.%/)01(#2#)013&.40) (Takiwaki, KK in prep)!/0.12.#)*-;,$+*)!"#$#%#&'&()*+,$#%#&-../! 83<;)$="&.!;2*&3+$*, 'D)*=;22*)2?9/B.4E.0.<*,+F27. '8*,()*+"+$,-.="2;

17 Easy to obtain explosions in 3D?( Yes or No!)!For working the neutrino-heating mechanism Suwa+(2010) The advection timescales become longer in 3D than in 2D.!For the hydrodynamic point of view, it may be more easier for 2D. (because matter motions can be concentrated along the special direction) Please stay tuned for our high resolution 3D simulations.

18 Conclusions $Larger symmetry energy & Smaller incompressibility is the best combination to blow up massive stars! $With currently available EOSs, only weak explosions have been obtained in the state-of-the-art 2D simulations. (e.g., Marek & Janka (2009), Suwa, KK et al. (2010)) * 3D supernova simulations equipped with accurate EOSs can be the only solution to understand the supernova mechanism. Thank you very much!