Topics in Nuclear Astrophysics

Transcription

1 Topics in Nucea Astophysics Michae Wiesche Univesity of Note Dame Hydogen buning in Sun xposive eactions in the SN shock font Heium buning in Red Giants Note Dame JINA ectues, Fa 003 p-pocess on acceting white dwafs Nova o neuton stas X-ay bust

2 Out-Line Genea concept and definitions Hydogen buning sequences Nuceosynthesis in ate stea evoution Nuceosynthesis in exposive buning in supenova xposive buning in catacysmic binay systems Nuceosynthesis in Big Bang and Cosmic Rays

3 Topics in Nucea Astophysics I Nucea Signatues & Nucea Physics Obsevationa Signatues Abundances Light-cuves & adioactivity Nucea enegy poduction ate Nucea eaction coss sections Nucea eaction mechanisms Techniques fo detemining coss sections

4 Signatues of Nuceosynthesis gaactic abundance distibution nuceosynthesis pocesses nuceosynthesis histoy of ou univese cosmic chemica evoution Abundance stea H-, He, C, O, Si-buning cosmic ays stas, supenovae s-pocess He-buning in AGB stas, massive stas p-pocess site disputed -pocess type II supenovae, meging neuton stas A

5 Refeences Chemica voution of Gaaxies J Audouze, B M Tinsey Annua Review of Astonomy and Astophysics. Voume 4, Page 43-79, Sep 976 ement Poduction in the ay Univese D N Schamm, R V Wagone Annua Review of Nucea Science. Voume 7, Page 37-74, Dec 977 ementa and Isotopic Composition of the Gaactic Cosmic Rays J A Simpson Annua Review of Nucea and Patice Science. Voume 33, Page 33-38, Dec 983 Nuceosynthesis J W Tuan Annua Review of Nucea and Patice Science. Voume 34, Page 53-97, Dec 984 NUCLOSYNTHSIS IN ASYMPTOTIC GIANT BRANCH STARS: Reevance fo Gaactic nichment and Soa System Fomation M. Busso, R. Gaino, G. J. Wassebug Annua Review of Astonomy and Astophysics. Voume 37, Page , Sep 999

6 Site-Specific Specific Nuceosynthesis Patten Nova Chanda Meta-Poo Hao Sta HST Mg Ne O On-ine obsevation of nuceosynthesis poducts!

7 Meteoites Chondites: Chondues - sma ~mm size spheica incusions in matix Meteoitic incusions ae eay condensates of nuceosynthesis eecta supenovae, novae, stea winds AGB stas STLLAR NUCLOSYNTHSIS AND TH ISOTOPIC COMPOSITION OF PRSOLAR GRAINS FROM PRIMITIV MTORITS nst Zinne, Annua Review of ath and Panetay Sciences. Voume 6, Page 47-88, May 998

8 Cosmo-Chemisty Chemisty of Meteoites Chondue AGB-Stas Supenovae Novae

9 Light and Light-Cuves Light intensity coeates with enegy-output Light cuve foows the adioactive decay aw 56 Ni, 56 Co, 44 Ti

10 Gaactic Radioactivity - γ-radiation Gamma-Ray Astonomy; R Ramaty, R Lingenfete, Annua Review of Nucea and Patice Science. Voume 3, Page 35-69, Dec 98 MeV-30 MeV γ-radiation in Gaactic Suvey 44 Ti in Supenova Cas-A Location.57 MeV γ-adiation Haf ife: 60 yeas

11 Nucea Reactions in Stas geneate enegy ceate new isotopes and eements γ Cp,γ 3 N eaction pobabiity σ: eaction coss section

12 Coss Section Coss Section a eminde! a eminde! coss section aea! [ ] fm A nuceus 3.6 σ poectie obita momentum D h D h h D h h b L b k b p b p b L k p ; obita momentum in σ b b F D D σ σ σ

13 Tansmission though the baie Tansmission though the baie,,, R G R F R P R P ϕ ϕ G B F A V V d d R e Z Z R V e Z Z nuc h h < ϕ ϕ µ µ R 0 F, G ae the Couomb wave functions

14 Coss section fo chaged patices xponentia decine towads owe enegy due to Couomb baie

15 Resonant Reaction Mechanism Resonant Reaction Mechanism esonance captue: popuation of unbound state in compound nuceus S in Sout x int C em gs L C s R out out in T s C in i f i H H P H P H P ψ ψ ψ ψ ψ ψ ψ ψ ψ ψ γ γ Γ Γ Γ Γ Γ Γ Γ T p out in J ω ω σ D

16 Diect Captue Mechanism one-step eaction mechanism though e-m inteaction σ P ψ H ψ ψ f em p T S in P is the penetabiity though the Couomb and obita momentum baie γ enegy changes with patice enegy

17 coss section fo neuton captue coss section fo neuton captue 0 d d h h ϕ µ µ no Couomb baie, ust obita momentum tem! k k k P k k P k P R P λ ϕ ϕ

18 Coss section fo neuta patices 0 0, s-wave foows /v aw,, p-wave expeiences obita momentum baie

19 Hause Feshbach Appoach Hause Feshbach Appoach assumption of many esonances! high eve density ρ in patice unbound egion of compound nuceus :,,,,,,,, T J T J T J T J m o i J tot o i i i δ σ D tansition pobabiity Smooth Couomb baie detemined enegy dependence!

20 invese eactions A a B b o B b A a

21 detaied baance theoem I A a C J B b ϕ H ϕ Bb ϕ H ϕ Bb identica matix eements fo tansition though same compound configuation σ σ Bb D D Bb A B J J a b ϕ ϕ Bb H ϕ H ϕ Bb

22 detaied baance theoem II A a C J B b theoem aows to cacuate eaction coss section fom known coss section of the invese eaction pocess! λ µ ; µ m m A A m m a a cm σ σ Bb B A b a m m B A m m b a Bb Ab

23 Concusion obsevationa indication fo nucea pocesses in the past and pesent univese! ow enegy eaction pocesses though esonant and non-esonant eaction channes coss section detemination though singe esonance fomaism diect captue o tansfe fomaism statistica mode fomaism detaied baance appoach