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Stellar Evolution and Nucleosynthesis Stellar Evolution and Nucleosynthesis Miklós Kiss Berze High School Gyöngyös Károly Róbert Campus, Eszterházy Károly University Gyöngyös, Hungary Lovas István (1931-2014) Thanks to István Lovas, who encouraged and helped me get started with the research work. I learned a lot from him about particles, gravity as well. 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 2. What makes stars hot? (The gravitational contraction.) What keeps a star shining (radiating)? (Nuclear fusion energy.) What is a star? (An object in which energy from nuclear reactions balances the radiation energy losses.) Gravitational contraction is the driver of stellar evolution. 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 3. HRD Absolute magnitude – Spectral type Luminosity – Temperature (Color) Stages of evolution Main sequence Red-giant branch White-dwarf branch Snapshot: evolutionary states of many stars 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 4. Interstellar medium Gas about 90% hydrogen by number about 9% helium remaining 1% heavier elements and some dust 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 5. Star formation I. Collapsing of an interstellar molecular cloud Jeans criteria (energy, mass, length, density) E tot = Ek + Egr < 0 The temperature - density diagram ( T −ρJ ) For a given Jeans mass 1 2 3 1 2fm 4πM 3 T = ρ⋅ J k3 3 Cooling or heating Opacity, infrared radiation Fragmentation 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 6. Star formation II. Infrared 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 7. Initial Mass Function (IMF) IMF is an empirical function that describes the distribution of initial masses for a population of stars. ∆N = f (m) ⋅ ∆m −α f (m) = K ⋅ m , where ;3,0 m < ,0 08 α = ,0;3,1 08 ≤ m < 5,0 ,2 35 5,0; m ≤ m (Thanks to Szalai Tamás, University of Szeged) 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 8. Mass and Evolution Minimum mass and maximum mass Mmin ≈ ,0 08⋅ MSun Mmax ≈100⋅ MSun (S. G. Ryan, A.J. Norton: Stellar Evolution and Nucleosynthesis, Cambridge 2010) Star states main sequence star red-giant star white-dwarf star neutron star supernovae: SNI, SNII black hole and some other 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 9. Mass depending stellar evolution 11 M ☉- - 8 M ☉ 11 M ☉ 0,5 M ☉-8 M ☉ 0,08 M ☉-0,5 M ☉ 0,0125 M ☉-0,08 M ☉ 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 10. Nucleosynthesis 1. Big Bang Nucleosynthesis 2. Stellar Nucleosynthesis a, fusion b, neutron capture nucleosynthesis 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 11. Big Bang Nucleosynthesis H, He p:n = 8:1 so H:He= 14:2 that is YHe~0,22. Recently YHe ~0,23. All hydrogen is from BBN and the vast majority of helium. 4He, D, 3He and 7Li They were produced during the first 20 minutes of the Universe when it was dense and hot enough for nuclear reactions to take place. Besides these isotopes, some minute traces of 6Li, 9Be, 11 B and CNO are produced by BBN. (Alain Coc: arXiv:1208.4748v1) 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 12. Stellar Nucleosynthesis: Fusion He: p-p CNO Heavier nuclei: 3α Formation of 12 C: crucial step: Beryllium dynamic equilibrium (life-time ~ 10 -16s) 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 13. Neutron Capture Nucleosynthesis Processes: s-process r-process and m-process (i-process) There is band instead of path! The beginning of the neutron capture nucleosynthesis 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 14. The profile of neutron capture band at tin isotopes 8 −3 ( n8 =10 cm ) 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 15. Neutron source and mass The two main processes: and The first process occurs in massive helium burning stars and in AGB TP, the second occurs in AGB stars at the TDU following the TP 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 16. Individual abundance Change the nucleon identification from the usual (Z,A) to (Z,N). This will allow us to read new information from the various measured abundances. Charts with isotopic and individual abundance notation For example 96 Zr has 2.80 percents isotopic abundance and 98 Mo has 24.13 percents. But individual abundances are 0,32 and 0,605. So such way one can see the real ratio between them. 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 17. Rate Analysis 1. Traditional approach "The success of any theory of nucleosynthesis has to be measured by comparison with the abundance patterns observed in nature." say Käppeler, Beer and Wisshak , that is, we need to create such model that gives back the observed abundance. (F. Käppeler, H. Beer and K. Wisshak, s-process nucleosynthesis-nuclear physics and the classical model: Rep. Prog. Phys. 52 (1989) 945-1013.) 2. New point of view It seems that the reverse approach is also useful: the abundance is the preserver of the nuclei’s formation conditions. So instead investigating whether the theoretical model fits the observed abundance, we look for the circumstances when the observed abundance is available. 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 18. Isotopic case 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 19. Isotonic case 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 20. The existence of 60 Fe radioisotope The 59 Co and 60 Fe abundance at different neutron density. The figure shows the difference between PFR and the branching factor PFR: Partial Formation Ratio (M. Kiss, Rate Analysis or a Possible Interpretation of Abundances PoS(NIC XIII)110) 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 21. Paths 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 22. AGB All experienced isotope ratios can be obtained both at 108 K temperature and at 3⋅108 K temperature at intermediate neutron density 12 14 −3 n n =10 −10 cm so the m-process and the AGB stars are probably one of the main places of nucleosynthesis. 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 23. WD initial mass – final mass estimation For a WD the minimal mass is 0,4 M☉, the maximal mass less than M Ch . MCh .= 1,4 M☉ M(final) = ,0 0988⋅M(initial) + ,0 4087 M☉ 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 24. How much matter (mass) was in an AGB star? How many stars are between m1 and m2 ? About IMF: m m2 m2 1−α 2 m K 1−α 1−α ∆N = f (m)dm = K ⋅ m−α dm = K = ()m − m ∫ ∫ 1−α 1−α 2 1 m1 m1 m1 But, how much mass is between m1 and m2 ? m m2 m2 2−α 2 m K 2−α 2−α m = g(m)dm = K ⋅ m1−α dm = K = ()m − m ∫ ∫ 2 −α 2 −α 2 1 m1 m1 m1 About these and the WD initial – final mass estimation: From the whole initial mass 64% were in an AGB star, and during the mass loss 37% mass returned into the ISM. At SNII from the initial mass only 19% mass returned into the ISM. 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 25. SNI SNII before SN after SN light curves are different for SNI and SNII 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 26. SNII SN 1987a “Approximately two to three hours before the visible light from SN 1987A reached Earth, a burst of neutrinos was observed at three separate neutrino observatories. This is likely due to neutrino emission, which occurs simultaneously with core collapse, but preceding the emission of visible light. Transmission of visible light is a slower process that occurs only after the shock wave reaches the stellar surface. At 07:35 UT, Kamiokande II detected 12 antineutrinos ; IMB, 8 antineutrinos; and Baksan, 5 antineutrinos; in a burst lasting less than 13 seconds. Approximately three hours earlier, the Mont Blanc liquid scintillator detected a five-neutrino burst, but this is generally not believed to be associated with SN 1987A" (https://en.wikipedia.org/wiki/SN_1987A) 10 th Bolyai-Gauss-Lobachevsky conference 08. 24. 2017. KRC EKU Gyöngyös Miklós Kiss, Berze High School Gyöngyös 27.
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