Classical Novae at the Crossroads of Astrophysics, Nuclear Physics and Cosmochemistry

Transcription

1 at the Crossroads of Astrophysics, Nuclear Physics and Cosmochemistry Jordi José Dept. Física i Enginyeria Nuclear, Univ. Politècnica de Catalunya (UPC) & Institut d Estudis Espacials de Catalunya (IEEC), Barcelona

2 Novae have been observed in all λ (detected in γ-rays for E>100 MeV) Moderate rise times (<1 2 days): 8 18 magnitude increase in brigthness L Peak ~ L Stellar binary systems: WD + MS (often, K-M dwarfs) Recurrence time: ~ 10 yr (RNe) 10 5 yr (CNe) Frequency: 30 ± 10 yr -1 [Obs.; ~ 5 yr -1 ] E ergs Mass ejected: M (~10 3 km s -1 )

3 Observational Astronomy Theoretical Astrophysics Nuclear & Atomic Theory Nuclear Experiments Conservation eqs. Hydrodynamics Energy transport Shell model Optical potentials Plasma properties Astrophysical Models Observables: light curves, spectra, abundances... Reaction rates, EOS, opacities... ~10 m ~1 10 μm Cosmochemistry Spectroscopy, photometry

4 Current Challenges for Classical Novae The amount of mass ejected predicted by 1-D models is somewhat smaller than that *inferred* observationally The mixing mechanism at work at the core-envelope interface during nova outbursts is not fully understood

5 H Model 1.35 M (50% ONe enrichment) T = K ρ = g cm -3 ε nuc = erg g -1 s -1 ΔM env = M He C B Be Li O N Ne F Al Mg Na Negligible contribution from any (n,γ) or (α,γ) reaction (that also applies Z to 15 O(α,γ)!) Fuel (H) is not fully consumed in the explosion T peak Si 9 10 P 11 S Ar Cl 8 Main 7 nuclear path 6 N close to the valley of stability, and driven by (p,γ), (p,α) and β + interactions K Ca Endpoint ~ Ca No heavy metals produced! (p,γ) (p,α) (β + ) T = 1 x 10 7 K Log (Reaction Fluxes) : -2 : -3 : -4 : -5 : -6 : -7

6 Degeneracy Lifting T T ψ ρ ρ T base = K T T ψ ρ ρ T ψ T JJ (2014), in preparation ψ ρ ρ

7 Nuclear Symphony Observational Constraints Multidimensional Models Nuclear Uncertainties See talks, this afternoon by: L. Sergi [ 17 O(p, α)] M. Gulino [ 18 F(p, α)] W. Richter [ 25 Al(p, γ)] Main nuclear uncertainties: [ 18 F(p,α) 15 O, 25 Al(p,γ) 26 Si, 30 P(p,γ) 31 S]

8 Nuclear Symphony Observational Constraints Multidimensional Models V838 Her

9 Nuclear Symphony Observational Constraints Multidimensional Models Observational Constraints Andrëa et al. (1994) PW Vul 1984 H He C N O Ne Na-Fe Z Observation Theory (JJ & Hernanz 1998)

10 Nuclear Symphony Observational Constraints Multidimensional Models Presolar Grains 1E+4 1E+3 1E+2 1E+1 1E+0 KFB1a-161 KJGM4C KJC112 KFC1a-551 KJGM4C AF15bC Mainstream ~93% A+B grains 4-5% X grains ~1% Y grains ~1% Z grains ~1% Nova grains (SiC) Nova grains (graphite) Solar 1E+0 1E+1 1E+2 1E+3 1E+4 12C/ 13 C KJGM4C KJGM4C AF15bC Solar KFC1a-551 Mainstream A+B grains X grains Y grains Z grains AF15bB Nova grains (SiC) Nova grains (Graphite) δ 30 Si/ 28 Si ( )

11 Nuclear Symphony Observational Constraints Multidimensional Models γ-ray Emission from Classical Novae Isotope Lifetime Disintegration Nova type 17 F 93 sec β + -decay CO & ONe 14 O 102 sec β + -decay CO & ONe 15 O 176 sec β + -decay CO & ONe 13 N 862 sec β + -decay CO & ONe 18 F 158 min β + -decay CO & ONe 7 Be 77 day e capture CO 22 Na 3.75 yr β + -decay ONe 26 Al 1.0 Myr β + -decay ONe * 14,15 O, 17 F ( 13 N): Expansion and ejection stages * 13 N, 18 F: Early gamma-ray emission (511 kev plus continuum) * 7 Be, 22 Na, 26 Al: Gamma-ray lines

12 Nuclear Symphony Observational Constraints Multidimensional Models 18 F * γ-ray signature: 18 F decay (T 1/2 ~ 110 min) provides a source of gamma-ray emission at 511 kev and below (related to electronpositron annihilation). But! Uncertainties in the rates translate into a factor 5-10 uncertainty in the expected fluxes! 1.15 M o CO Gómez-Gomar, Hernanz, JJ, & Isern (1998), MNRAS D= 1 kpc

13 MareNostrum II (BSC, 2006), Tflops/s, 10,240 processors MareNostrum III (BSC, Jan. 2013), >1 Petaflop/s, 48,000 processors [6,000 Intel SandyBridge chips (2,6 GHz), each with 8 cores]

14 Nuclear Symphony Observational Constraints Multidimensional Models 3D Models of Mixing Z mean ~

15 Thank you for your attention! Classical Novae at the Crossroads of Astrophysics, Nuclear Physics and Cosmochemistry XXVII Texas Symp. on Relativistic Astrophysics Dallas (Texas), Dec. 8 13, 2013