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Characteristic initial masses

Characteristic initial masses. Chang, Seo-Won. Magic Numbers?. 6563, 4861, 3968, 3933, …. 1100, 3000, 0, 2.73 4, 19, 26, 27, 30, 42 0.08, 1.1, 1.8-2.2, 8 , 60. (1) Lotto = Chance & Probability (2) Physics = Meaning & interpretation (3) Astronomy = Experience & Feeling &

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Characteristic initial masses

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  1. Characteristic initial masses Chang, Seo-Won

  2. Magic Numbers? • 6563, 4861, 3968, 3933, …. • 1100, 3000, 0, 2.73 • 4, 19, 26, 27, 30, 42 • 0.08, 1.1, 1.8-2.2, 8 , 60 (1) Lotto = Chance & Probability (2) Physics = Meaning & interpretation (3) Astronomy = Experience & Feeling & (1) & (2) & ….

  3. Stellar structure & Evolution • T • P • M • E

  4. MH ~ 0.08 M⊙ on MS • ‘H’ means Hydrogen • Less massive than MH : never burn H • Brown dwarf & Black dwarf

  5. Mconv ~ 1.1 M⊙ on MS • ‘conv’ means Convection • More massive than Mconv : Have Convective cores (engulfs the core only ~ @1.5 M⊙) • Why they have convective cores?

  6. MHeF ~ 1.8-2.2 M⊙ on MS • ‘HeF’ means Helium Flash • Depending on the X, Y, Z • Less massive than MHeF : experience HeF (explosive ignition of He core ~ 0.45 M⊙) • More massive than MHeF : Fig 5-5.

  7. Mup ~ 8 M⊙ on MS • ‘up’ means … • C ignite quiescently in the core (~50 M⊙ -> Fe-peak nuclei) • Core implodes leads to the formation of either a neutron star or a black hole (Fig 5.6).

  8. Mee ~ 60 M⊙ on MS • ‘ee’ means e-e+ (pair-production instability) • Unstable before forming Fe core (largely O core @ instability) • Te ~ 2 x 107 K • Several Pulsations

  9. Mi ~ Mr • Remnant-mass-initial-mass relation (Fig 5.7). • Stellar Evolution • Mi > 0.8 M⊙ : climbs slowly (WD) • Mi = 8 M⊙ : Transition (WD -> NS), Mr = 1.4 • Mi = 60-90M⊙ : Uncertain (NS -> BH), 1.4 < Mr < 3M⊙ Mr Mi

  10. In particular.. • It makes clear that stars eventually return most of their mass to the ISM.

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