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INTERMEDIATE MASS STARS

INTERMEDIATE MASS STARS. Luciano Piersanti. Oscar Straniero. INAF – Osservatorio Astronomico di Teramo. CLAUS2009 - Anacapri, May 14th - 16th. e-Capture SNe. CO White Dwarfs. Explode as CC-SNe. Classification. Criterion:.

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INTERMEDIATE MASS STARS

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  1. INTERMEDIATE MASS STARS Luciano Piersanti Oscar Straniero INAF – Osservatorio Astronomico di Teramo CLAUS2009 - Anacapri, May 14th - 16th

  2. e-Capture SNe CO White Dwarfs Explode as CC-SNe Classification Criterion: Onset of a given nuclear burning and/or physical conditions at the ignition NO C-burning Ignition C-burning Ignition Low Mass Stars Intermediate Mass Stars SuperAGBStars Massive Stars They form a ONeMg degenerate core He-flash at the RGB tip Quiescent ignition of He-burning After C-burning, they ignite O-, Ne-, Si-burning CLAUS2009 - Anacapri, May 14th - 16th

  3. Leading Parameter The final fate of single stars is determined by their MS mass! For a fixed initial chemical composition Increasing the initial mass… • The central temperature increases in the MS phase • The He core produced via H-burning increases • The mass extension of the convective He-core in He-burning is larger • The CO core after central He-burning increases • The CO core after central He-burning increases CLAUS2009 - Anacapri, May 14th - 16th

  4. Mass Limit I/1 LOW MASS STAR H 4He 16O 12C 14N M=1.2 M Z=0.0149 Y=0.2645 CLAUS2009 - Anacapri, May 14th - 16th

  5. H 4He 16O 12C 14N Mass Limit I/2 INTERMEDIATE MASS STAR M=3.5 M Z=0.0149 Y=0.2645 CLAUS2009 - Anacapri, May 14th - 16th

  6. The off MS evolution is not controlled by the growth of the He core (Dominguez et al. 1999) The He-core mass at the He-ignition is comparable with the mass of the convective core in H-burn. Mass Limit I/3 CLAUS2009 - Anacapri, May 14th - 16th

  7. H 4He 16O 14N 12C Mass Limit II/1 M=3.5 M Z=0.0149 Y=0.2645 CLAUS2009 - Anacapri, May 14th - 16th

  8. Observational Evidence 20 Type IIp SNe The lower limit for SNe IIp is ~8 M The upper limit for SNe IIp is ~16.5 M

  9. H 4He 16O 20Ne 12C Mass Limit II/2 M=8.5 M Z=0.0149 Y=0.2645 CLAUS2009 - Anacapri, May 14th - 16th

  10. 4He H 20Ne 16O 12C Mass Limit II/3 M=11.0 M Z=0.0149 Y=0.2645 CLAUS2009 - Anacapri, May 14th - 16th

  11. Mass Limit II/3 The value of Mup is determined by: The Physics of stellar plasma (EOS) The plasma neutrino production The rate of the 12C+12C reaction CLAUS2009 - Anacapri, May 14th - 16th

  12. Beyond the Central He-Burning CLAUS2009 - Anacapri, May 14th - 16th

  13. M=2M 12C Z=Z 13C 14N 22Ne 23Na H The Formation of the 13C Pocket CLAUS2009 - Anacapri, May 14th - 16th

  14. TDU episodes The AGB Phase M=2M Z=Z CLAUS2009 - Anacapri, May 14th - 16th

  15. The High Mass Tail For M> 3.5 M  TCE > 2x107 K Hot Bottom Burning Activation of CNO, NeNa, MgAl cycles O, Na, Mg, Al anomalies in GCs Production of primary N in low metallicity stars Self pollkution of He-rich material in GCs CLAUS2009 - Anacapri, May 14th - 16th

  16. (Prada Moroni & Straniero 2007) White Dwarfs Initial-to-final mass relation CLAUS2009 - Anacapri, May 14th - 16th

  17. The core is fully degenerate The external layers are very cool Neutrino energy losses are negligible (Prada Moroni & Straniero 2007) The WD Cooling Sequence The evolution is driven by the heat capacity of the core and the opacity in the external layers O (later on C) cristallizes Latent heat is released in the core External convection joints zones where thermal conduction is very efficient CLAUS2009 - Anacapri, May 14th - 16th

  18. IMS in Binary Systems Roche Geometry CLAUS2009 - Anacapri, May 14th - 16th

  19. The Accretion Scenario Single Degenerate System Double Degenerate System CLAUS2009 - Anacapri, May 14th - 16th

  20. Type Ia Supernovae are produced by the thermonuclear disruption of CO WDs which approach MCh due to mass accretion from their companions in binary systems He C/O Hoyle & Fowler (1960) H Type Ia Supernovae SD Scenario DD Scenario CLAUS2009 - Anacapri, May 14th - 16th

  21. (Gallagher et a. 2005) Type Ia Supernovae CLAUS2009 - Anacapri, May 14th - 16th

  22. MASSIVE STARS M=11.0 M Z=0.0149 Y=0.2645 CLAUS2009 - Anacapri, May 14th - 16th

  23. ‘ The value of Mup CF88 M=8.5 M Z=0.0149 Y=0.2645 NEW RATE CLAUS2009 - Anacapri, May 14th - 16th

  24. 9 10 The Theoretical Scenario Heger et al. 2003 CLAUS2009 - Anacapri, May 14th - 16th

  25. Observational Evidence 20 Type IIp SNe The lower limit for SNe IIp is ~8 M The upper limit for SNe IIp is ~16.5 M

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