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Alessandro Chieffi INAF – Istituto di Astrofisica e Planetologia Spaziale Italy

 The evolution of massive stars: what we know and what we would like to know. Alessandro Chieffi INAF – Istituto di Astrofisica e Planetologia Spaziale Italy Centre for Stellar and Planetary Astrophysics Monash University – Australia

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Alessandro Chieffi INAF – Istituto di Astrofisica e Planetologia Spaziale Italy

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  1.  The evolution of massive stars: what we know and what we would like to know Alessandro Chieffi INAF – Istituto di Astrofisica e Planetologia Spaziale Italy Centre for Stellar and PlanetaryAstrophysicsMonashUniversity – Australia Institut d’Astronomie et Astrophysique - ULB – Bruxelles alessandro.chieffi@inaf.it In collaboration with: Marco Limongi INAF –Osservatorio Astronomico di Roma, Italy Institute for the Physics and Mathematics of the Universe, Japan Centre for Stellar and PlanetaryAstrophysicsMonashUniversity – Australia marco.limongi@inaf.it Our models may be found in our webpage O.R.F.E.O. : http://orfeo.iaps.inaf.it

  2. Massive stars play a key role in the physical and chemical evolution of the universe because are responsible for: the synthesis of a large number of nuclear species (including long living radioactive nuclei presently detected in the disk of our galaxy) the injection in the environment of a large amount of kinetic energy and neutrinos leave compact remnants (neutron stars and black holes) A large number of “phenomena” we do observe in the sky are connected to the evolution of massive stars: Blue and Red Supergiants, WR stars, a variety of core collapse supernovae, masses of the remnant, Cosmic rays, Gamma ray burst. Etc..

  3. PRESUPERNOVA EVOLUTION Allmodelscomputed with the FRANEC (Frascati RAphson Newton Evolutionary Code) 6.0 (CHIEFFI & LIMONGI) • FULL COUPLING of: Physical Structure - Nuclear Burning - Chemical Mixing (convection, semiconvection) • INCLUSION OF ROTATION: • - Shellular Rotation (Meynet & Maeder 1997) • - Transport of Angular Momentum: shear and meridional circulation • - Rotation and Mass Loss coupled • (wind carries angular momentum and mechanical mass loss due to rotation) - TWO NUCLEAR NETWORKS: - 200 isotopes from n to 209Bi (500 reactions) H/He Burning - 320 isotopes from n to 209Bi (3000 reactions) Advanced Burning - MASS LOSS: - OB: Vink et al. 2000,2001 - RSG: de Jager 1988+Van Loon 2005 (Dust driven wind) - WR: Nugis & Lamers 2000 - Supra Eddington Mass Loss - Mechanical mass loss due to rotation

  4. Explosion and Nucleosynthesis (LIMONGI) Propagation of the shock wave followed by means of a code, developed by us, that solves the fully compressible reactive hydrodynamic equations using the piecewise parabolic method (PPM - Colella & Woodward 1984) in the Lagrangean form. Chemical evolution of the matter computed by coupling the same nuclear network adopted in the hydrostatic calculations to the system of hydrodynamic equations.

  5. GRID OF MODELS INITIAL MASSES: 13, 15, 20, 25, 30, 40, 60, 80 and 120 M INITIAL EQUATORIAL ROTATIONAL VELOCITIES: 0, 150, 300 km/s 4 INITIAL CHEMICAL COMPOSITIONS:

  6. Massive Stars O burn e+ + e- Ne burn C burn He burning H burning

  7. Massive Stars O burn e+ + e- Ne burn C burn He burning H shell H burning He shell C/O shell Ne/O shell mantle O shell Si shell “Fe” core

  8. remnant

  9. Fe Z=N H burning Mn Cr He burning V Ti C burning Sc Ca CNex burning K Siix & Ox burning Ar Cl Ox burning S P Si Protons Al Mg Na Ne F O N C Neutrons

  10. Z=N Ge Ga Zn Cu Ni Co Fe Mn Cr V Ti Six + Heburn burning Cshell+(C&Ne)x Six burning Siix burning Siix & Ox burning

  11. Ti = 48Ti = 48Cr (Siix) V = 51V = 51Mn (Siix) Cr = 52Cr = 52Mn (Siix) Mn = 55Mn = 55Co (Siix) Fe = 56Fe = 56Ni (Six+Siix) Co = 59Co = 59Cu (Six) Ni = 58Ni (Six) Cu = 63Cu = 63Ge (Six+Heburn) Zn = 64Zn (Six+Heburn) + 66Zn (Six+Heburn,Cburn) + 68Zn(Heshell+Cshell) Z=N Ge Ga Zn Cu Ni Co Fe Mn Cr V Ti Six + Heburn burning Cshell+(C&Ne)x Six burning Siix burning Siix & Ox burning

  12. [Fe/H]=0 PF= Xejected/Xinitial

  13. [Fe/H]=-2 PF= Xejected/Xinitial

  14. Massive Stars: Kippenhahn diagram M < 25/30 M⦿ M > 25/30 M⦿ He He C C O C Si O C O H He Si He H Ne Si O C O Si Ne

  15. SHEAR INSTABILITY Maeder & Zahn (1998) – Meynet and Maeder (2003) (𝛠2 , 𝑣2) 𝚫z 0 (𝛠1 , 𝑣1) The strict application of the Richardson criterion basically does not activate the Shear.

  16. Massive stars Mass loss rate: Vink (BSG) & De jager (RGB) & Van Loon (dust) [Fe/H]=0 [Fe/H]=-2

  17. CORE COLLAPSE SUPERNOVAE: ENERGETICS ndiffusion Combining all the energy required to explain the SN display with all the energy lossess we get n n n-sphere There isplenty of energy to drive a succesfulexplosion! n n Neutrino Trapping Stalled Shock n n Energy Losses 1 x 1051 erg/0.1M n n “Prompt”shockseventuallystall!

  18. CORE COLLAPSE SUPERNOVAE: EXPLOSION In spite of the many efforts, just a few successful explosions have been obtained up to now, but only towards the lower end of the massive stars: 9-10 M⦿. Gain region Escamotage: Just assume that the shock wave comes out of the Fe core deposit by hand energy to trigger the shock wave Cooling region Different techniques adopted: - The piston (Woosley + ) - The thermal bomb (Nomoto +) - The kinetic bomb (Limongi & Chieffi) - The calibration of the energy returned by the neutrino sea to the star (Suckbold, Ertl) 100 50 200 km

  19. All stars eject 0.07 M☉ of 56Ni M&FB + all stars eject 0.07 M☉ of 56Ni Recommended scenario

  20. Our current recommended scenario is: 13 ≤ M(M⊙) ≤ 25 Mixing and fall back as suggested by Umeda & Nomoto (2002): Inner border fixed by requiring [Ni/Fe]=0.2 Outer border fixed at the base of the Oxygen burning shell Mass of the remnant fixed by requiring the ejection of 0.07 M⊙ of 56Ni 25 < M(M⊙) ≤ 120 Mass of the remnant equal to the current mass at the core bounce

  21. The interplaybetween He and H burnings in Core He Burning Primary Nitrogen Primary Neutrons H burning 12C 14N – 13C He burning

  22. The interplaybetween He and H burnings in Core He Burning H burning 12C 14N – 13C 14N(α,γ)18F(β+)18O(p,α)15N(α,γ)19F Goriely, S., Jorissen, A., Arnould, M. 1989 He burning 14N(n,p)14C 13C(α,n)16O

  23. v=0 v=300 km/s M=15 MO – [Fe/H]=0 Hec=0 Hec=0 He 14N 13C 14N Log10(X) Log10(X) X(He) X(He) He 13C 19F 19F mass mass Core collapse He Core collapse 14N 19F Log10(X) Log10(X) X(He) X(He) 13C 13C 19F 14N He mass mass

  24. [Fe/H]=0 V=0 V=300 km/s

  25. [Fe/H]=-2 V=0 V=300 km/s

  26. [Fe/H]=0 [Fe/H]=-1 [Fe/H]=-2 [Fe/H]=-3

  27. [Fe/H]=0 [Fe/H]=-1 [Fe/H]=-2 [Fe/H]=-3 X 13C solid 18O dashed

  28. If I could ask for three wishes to the genie of the lamp I would ask:

  29. If I could ask for three wishes to the genie of the lamp I would ask: 1) To know everything about “instabilities”

  30. If I could ask for three wishes to the genie of the lamp I would ask: 1) To know everything about “instabilities” 2) To know the nuclear cross sections for all processes

  31. Summary We have a new very extended grid of models and associated yields that range in mass between 13 and 120 solar masses, in [Fe/H] between 0 and -3, and extend in initial rotational velocity up to 300 km/s At solar metallicity the effect of rotation (for v up to 300 km/s) is modest As the metallicity reduces, the effect of rotation on the yields increases and affects mainly N, F and the S-process elements due to the interplay between the He core and H burning shell. At the lowest metallicities nuclear species up to Pb are produced in significant amount By combining the currently observed upper limit of Ekin = 3 FOE for the kinetic energy of the ejecta of the Type IIP supernovae and the relation between compactness of a star and its capability of exploding we obtain that only stars less massive than 30 M☉ my explode These constraints also imply that remnant masses in excess of 30 or more solar masses may be routinely produced in a collapse

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