Classical Novae 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

Moderate rise times (<1 – 2 days): 8 – 18 magnitude increase in brigthness LPeak ~ 104 – 105 L Stellar binary systems: WD + MS (often, K-M dwarfs) Recurrence time: ~ 10 yr (RNe) – 105 yr (CNe) Frequency: 30 ± 10 yr-1

[Obs.; ~ 5 yr-1]

E ∼ 1045 ergs

Mass ejected: 10-4 – 10-5 M

(~103 km s-1)

Novae have been observed in all λ (detected in γ-rays for E>100 MeV)

J. José Classical Novae

Theoretical Astrophysics

Observational Astronomy

Nuclear & Atomic Theory

Nuclear Experiments

Conservation eqs. Hydrodynamics Energy transport

Shell model Optical potentials Plasma properties

Reaction rates, EOS, opacities...

Astrophysical Models

Cosmochemistry

Spectroscopy, photometry

Observables: light curves, spectra, abundances...

~1 – 10 μm

~10 m

J. José Classical Novae

J. José

Current Challenges for Classical Novae

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

H He

Li Be B C

0 1 2

3 4 5

6 7

8 9 10

11

N O

F Ne

Na Mg Al

Si P

S Cl Ar

K Ca

N

Z 12

13 14

15 16

17 18 20 19

T = 1 x 107 K

Model 1.35 M (50% ONe enrichment)

(p,γ)

(p,α) (β+)

Log (Reaction Fluxes) : -2 : -3 : -4

: -6 : -5

: -7

T = 3.2×108 K ρ = 5.1×102 g cm-3

εnuc = 4.3×1016 erg g-1 s-1

ΔMenv = 5.4×10-6 M

Endpoint ~ Ca No heavy metals produced!

Negligible contribution from any (n,γ) or (α,γ) reaction (that also applies to 15O(α,γ)!)

Main nuclear path close to the valley of stability, and driven by (p,γ), (p,α) and β+ interactions

Tpeak

Fuel (H) is not fully consumed in the explosion

T

T

T

T

T

T

ρ

ρ

ρ

ρ

ρ

ρ ψ

ψ

ψ

ψ

Tbase = 3×107 K

JJ (2014), in preparation

Degeneracy Lifting

Nuclear Uncertainties

Main nuclear uncertainties: [18F(p,α)15O, 25Al(p,γ)26Si, 30P(p,γ)31S]

J. José Classical Novae Nuclear Symphony || Observational Constraints || Multidimensional Models

See talks, this afternoon by: L. Sergi [17O(p, α)] M. Gulino [18F(p, α)] W. Richter [25Al(p, γ)]

J. José

V838 Her

Classical Novae Nuclear Symphony || Observational Constraints || Multidimensional Models

Andrëa et al. (1994)

PW Vul 1984 H He C N O Ne Na-Fe Z Observation 0.47 0.23 0.073 0.14 0.083 0.0040 0.0048 0.30 Theory 0.47 0.25 0.073 0.094 0.10 0.0036 0.0037 0.28 (JJ & Hernanz 1998)

J. José Classical Novae Nuclear Symphony || Observational Constraints || Multidimensional Models

Observational Constraints

-400

-200

0

200

-200 0 200 400 600 800 1000 1200δ30Si/28Si (‰)

Mainstream

Y grainsX grainsA+B grains

Nova grains (Graphite)Nova grains (SiC)Z grains

Solar

AF15bC-126-3

AF15bB-429-3

KFC1a-551

KJGM4C-311-6

KJGM4C-100-3

1E+0

1E+1

1E+2

1E+3

1E+4

1E+0 1E+1 1E+2 1E+3 1E+412C/13C

Mainstream ~93%A+B grains 4-5%

Nova grains (graphite)Nova grains (SiC)Z grains ~1%Y grains ~1%X grains ~1%

Solar

KJGM4C-311-6

KJGM4C-100-3

KJC112 AF15bC-126-3

KFC1a-551

KFB1a-161

J. José

Presolar Grains

Classical Novae Nuclear Symphony || Observational Constraints || Multidimensional Models

* 14,15O, 17F (13N): Expansion and ejection stages * 13N, 18F: Early gamma-ray emission (511 keV plus continuum) * 7Be, 22Na, 26Al: Gamma-ray lines

Isotope Lifetime Disintegration Nova type 17F 93 sec β+-decay CO & ONe 14O 102 sec β+-decay CO & ONe 15O 176 sec β+-decay CO & ONe 13N 862 sec β+-decay CO & ONe 18F 158 min β+-decay CO & ONe 7Be 77 day e—capture CO

22Na 3.75 yr β+-decay ONe 26Al 1.0 Myr β+-decay ONe

γ-Ray Emission from Classical Novae

J. José Classical Novae Nuclear Symphony || Observational Constraints || Multidimensional Models

* γ-ray signature: 18F decay (T1/2 ~ 110 min) provides a source of gamma-ray emission at 511 keV and below (related to electron-positron annihilation). But! Uncertainties in the rates translate into a factor ∼ 5 - 10 uncertainty in the expected fluxes! 1.15 Mo CO

D= 1 kpc Gómez-Gomar, Hernanz, JJ, & Isern (1998), MNRAS

J. José Classical Novae Nuclear Symphony || Observational Constraints || Multidimensional Models

18F

MareNostrum II (BSC, 2006), 94.21 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]

J. José

Zmean ~ 0.2 – 0.3

3D Models of Mixing

Classical Novae Nuclear Symphony || Observational Constraints || Multidimensional Models

Classical Novae at the Crossroads of Astrophysics, Nuclear Physics and Cosmochemistry XXVII Texas Symp. on Relativistic Astrophysics

Dallas (Texas), Dec. 8 – 13, 2013

Thank you for your attention!