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Evolution and Fate of Intermediate Mass Stars: A Stellar Astrophysics Study

Explore the classification, ignition processes, and evolutionary outcomes of Intermediate Mass Stars. Understand the role of nuclear burning, observational evidence of supernovae, and the formation of white dwarfs in binary systems. Dive into high-mass star phenomena and supernova scenarios. Unveil the mysteries of stellar plasma physics and core evolution.

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Evolution and Fate of Intermediate Mass Stars: A Stellar Astrophysics Study

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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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