1

NucleosynthesisNucleosynthesis in in ClassicalClassical NovaeNovae

Jordi JoséDept. Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya

& Institut d’Estudis Espacials de Catalunya, Barcelona

Stellar Explosions: Classical Novae, SNIa, & XRBsStellar ExplosionsStellar Explosions: : Classical NovaeClassical Novae, , SNIaSNIa, & , & XRBsXRBs

MS Companion

WD/NS Star

Mass transfer:

Roche lobe overflow (L1)

Close Binary System

Type Ia (or thermonuclear) Supernovae [SN Ia]

Classical Nova Outbursts [CN]

X-Ray Bursts [XRBs]:

Type Ia (or thermonuclear) Supernovae [SN Ia]

Classical Nova Outbursts [CN]

X-Ray Bursts [XRBs]:

WD

NS

2

Classical Nova OutburstsClassicalClassical Nova Nova OutburstsOutbursts

Discovered more than 2.000 years ago... Observed in all wavelengths

(but never detected so far in γ-rays)

Discovered more than 2.000 years ago... Observed in all wavelengths

(but never detected so far in γ-rays)

CNe:

Moderate rise times (<1 – 2 days):

8 – 18 magnitude increase in brigthness

LPeak ~ 104 Lo

Recurrence time: ~ 104 – 105 yr

Frequency: 30 ± 10 yr-1

E ∼ 1045 erg

Mass ejected: 10-4 – 10-5 Mo

(102 – 103 km s-1)

CNeCNe::

Moderate rise times (<1 – 2 days):

8 – 18 magnitude increase in brigthness

LPeak ~ 104 Lo

Recurrence time: ~ 104 – 105 yr

Frequency: 30 ± 10 yr-1

E ∼ 1045 erg

Mass ejected: 10-4 – 10-5 Mo

(102 – 103 km s-1)

Pioneering TNR models: Starrfield et

al. 1972; Prialnik, Shara, & Shaviv

1978

Pioneering TNR models: Starrfield et

al. 1972; Prialnik, Shara, & Shaviv

1978

Nova Cygni 1992

Nova NucleosynthesisNova Nova NucleosynthesisNucleosynthesis

* Classical Novae: ~ 100 relevant isotopes (A<40) & a

(few) hundred nuclear reactions (Tpeak ~ 100 – 400 MK)

“Novae as unique stellar explosions for which the nuclear

physics input is/will be soon primarily based on

experimental information” (José, Hernanz & Iliadis 2006)

* Classical Novae: ~ 100 relevant isotopes (A<40) & a

(few) hundred nuclear reactions (Tpeak ~ 100 – 400 MK)

“Novae as unique stellar explosions for which the nuclear

physics input is/will be soon primarily based on

experimental information” (José, Hernanz & Iliadis 2006)

3

TTpeakpeak

1.35 Mo ONe

Endpoint of (classical) nova nucleosynthesis ~ CaEndpoint of (classical) nova nucleosynthesis ~ Ca

Negligible contribution from any (n,γ) or (α,γ) reaction: No 15O(α,γ), please!Negligible contribution from any (n,γ) or (α,γ) reaction: No 15O(α,γ), please!

The Nuclear Physics of Classical NovaeThe Nuclear Physics of Classical Novae

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

(p,α) and β+ reactions

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

(p,α) and β+ reactions

Relevant nucleosynthesis involves ~ 100 isotopes (Z ~ 20) & a (few)

hundred nuclear reactions (based primarily on experimental information)

Relevant nucleosynthesis involves ~ 100 isotopes (Z ~ 20) & a (few)

hundred nuclear reactions (based primarily on experimental information)

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

4

Triggering reaction: 12C(p,γ)13N

As T increases: τ(p,γ)[13N] < τ(β+)[

13N] 13N(p,γ)14O (hot CNO)14N(p,γ)15O16O(p,γ)17F

Triggering reaction: 12C(p,γ)13N

As T increases: τ(p,γ)[13N] < τ(β+)[

13N] 13N(p,γ)14O (hot CNO)14N(p,γ)15O16O(p,γ)17F

13N(β+)13C(p,γ)14N (cold CNO)

Sudden release of energy from these short-lived species powers the

expansion and ejection stages [Starrfield et al.1972]:15N, 17O (13C)

Sudden release of energy from these short-lived species powers the

expansion and ejection stages [Starrfield et al.1972]:15N, 17O (13C)

Critical role of convection: carrying the short-lived, β+-unstable

nuclei 14, 15O, 17F (13N) to the outer, cooler layers of the envelope

(escaping deadly p-capture reactions)

Critical role of convection: carrying the short-lived, β+-unstable

nuclei 14, 15O, 17F (13N) to the outer, cooler layers of the envelope

(escaping deadly p-capture reactions)

Without convection, there’s no nova outburst!

Hydrodynamic nova models Mass ejection (~ 2 x 10-5 Mo)

Since Tpeak ~ (2 - 3) x 108 K Nuclear processed material

Which is the role of nova outbursts in the

Galactic chemical puzzle?

Novae scarcely contribute to the Galactic abundances, but they

can be likely sites for the synthesis of individual nuclei with

overproduction factors, f = Xi / Xi, solar > 1000

Novae scarcely contribute to the Galactic abundances, but they

can be likely sites for the synthesis of individual nuclei with

overproduction factors, f = Xi / Xi, solar > 1000

Galactic nova rate: ~ 30 events.yr-1

Galaxy’s lifetime: ~ 1010 yr

Mean ejected mass per outburst: ~ 2 x 10-5 Mo

~ 6 x 106 Mo (~ 1/3000 of the Galactic

disk’s gas & dust component)

5

1.15 Mo ONe

José & Hernanz (1998), ApJ

1.35 Mo ONe

1.15 Mo CO

Classical novae are likely sites for the

synthesis of a significant fraction of

the Galactic 13C, 15N & 17O, and

contribute to the Galactic content of

other species like 7Li, or 26Al

Classical novae are likely sites for the

synthesis of a significant fraction of

the Galactic 13C, 15N & 17O, and

contribute to the Galactic content of

other species like 7Li, or 26Al

Main radioactive species synthesized during nova outbursts

* 14, 15O, 17F (13N): Expansion and ejection stages

* 13N, 18F: Early gamma-ray emission (511 keV plus continuum)

* 7Be, 22Na, 26Al: Gamma-ray lines

ONeONeβ+-decay1.0 Myr26Al

ONeONeβ+-decay3.75 yr22Na

COCOe--capture77 day7Be

CO & CO & ONeONeβ+-decay158 min18F

CO & CO & ONeONeβ+-decay862 sec13N

CO & CO & ONeONeβ+-decay176 sec15O

CO & CO & ONeONeβ+-decay102 sec14O

CO & CO & ONeONeβ+-decay93 sec17F

NovaNova typetypeDisintegrationDisintegrationLifetimeLifetimeIsotopeIsotope

Nova Radioactivities: 18F, 22Na, 26AlNova Radioactivities: 1818F, F, 2222Na, Na, 2626AlAl

6

* Clayton & Hoyle (1974): potential role of 22Na for diagnosis of

nova outbursts

1.275 MeV

τ ~ 3.75 yr22Na 22Ne

* Iyudin et al. (1995): upper limit of 3.7 x 10-8 Mo of22Na ejected

by any novae in the Galactic disk

Constraints on pre-existing theoretical models!

22Na22Na

22Na cumulative emission

1.15 Mo ONe

D= 1 kpc

Peak fluxes for the 1275 keV γ-ray line (22Na decay) might be

detectable by near future gamma-ray satellites (i.e.

INTEGRAL: d<0.5 kpc)

Peak fluxes for the 1275 keV γ-ray line (22Na decay) might be

detectable by near future gamma-ray satellites (i.e.

INTEGRAL: d<0.5 kpc)

Gómez-Gomar, Hernanz, José,

& Isern (1998), MNRAS

Jean, Hernanz, Gómez-Gomar,

& José (2000), MNRAS

7

Main contributor to the prompt gamma-ray emission

Nuclear uncertainties: 18F(p,γ)19Ne, 18F(p,α)15O, 17O(p,γ)18F,17O(p,α)14N (Hernanz, José, Coc, Gómez-Gomar, Isern 1999;

Coc, Hernanz, José, Thibaud 2000)

Recent improvements:

de Séréville et al. (2003), Bardayan et al. (2003),

Kozub et al. (2004), Chae et al. (2006): 18F(p,α)15O

Fox et al. (2004, 2005), Chafa et al. (2005, 2007): 17O(p,α), 17O(p,γ)

18F decay (τ ~ 158 min) provides a source of gamma-ray emission

at 511 keV and below (related to electron-positron annihilation).

But! Uncertainty in the predicted fluxes (nuclear physics origin)

18F18F

In situ observations (highly risky...)In situ observations (highly risky...)

Constraining theoretical predictions of Classical Nova ModelsConstraining theoretical predictions of Classical Nova Models

8

Models vs. Observations for Some Classical Nova SystemsModels vs. Observations for Some Classical Nova Systems

H He C N O Ne Na-Fe Z

V693 CrA 1981

Vanlandingham et al. (1997) 0.25 0.43 0.025 0.055 0.068 0.17 0.058 0.32

ONe3 (JH98) 0.30 0.20 0.051 0.045 0.15 0.18 0.065 0.50

Andreä et al. (1994) 0.16 0.18 0.0078 0.14 0.21 0.26 0.030 0.66

ONe4 (JH98) 0.12 0.13 0.049 0.051 0.28 0.26 0.10 0.75

Williams et al. (1985) 0.29 0.32 0.0046 0.080 0.12 0.17 0.016 0.39

ONe5 (JH98) 0.28 0.22 0.060 0.074 0.11 0.18 0.071 0.50

V1370 Aql 1982

Andreä et al. (1994) 0.044 0.10 0.050 0.19 0.037 0.56 0.017 0.86

ONe7 (JH98) 0.073 0.17 0.051 0.18 0.14 0.24 0.14 0.76

Snijders et al. (1987) 0.053 0.088 0.035 0.14 0.051 0.52 0.11 0.86

ONe7 (JH98) 0.073 0.17 0.051 0.18 0.14 0.24 0.14 0.76

PW Vul 1984

Andreä et al. (1994) 0.47 0.23 0.073 0.14 0.083 0.0040 0.0048 0.30

CO4 (JH98) 0.47 0.25 0.073 0.094 0.10 0.0036 0.0017 0.28

QU Vul 1984

Austin et al. (1996) 0.36 0.19 ...... 0.071 0.19 0.18 0.0014 0.44

ONe1 (JH98) 0.32 0.18 0.030 0.034 0.20 0.18 0.062 0.50

A rare variety of SiC grains (<1%),

together with a couple of graphite

grains, have been atributed to

classical nova outbursts (Amari et

al. 2001, Amari 2002).

A rare variety of SiC grains (<1%),

together with a couple of graphite

grains, have been atributed to

classical nova outbursts (Amari et

al. 2001, Amari 2002).

Supernovae

C stars?AGBs

AGBsPresolar Grains: Gifts from HeavenPresolarPresolar GrainsGrains: : GiftsGifts fromfrom HeavenHeaven

9

Five SiC and two graphite grains, whose isotopic ratios point toward

a nova origin: low 12C/13C and 14N/15N ratios, high 30Si/28Si, and

close-to-solar 29Si/28Si. 26Al/27Al and 22Ne/20Ne ratios have been

determined for some of these grains, with values compatible with

nova model predictions. (

Five SiC and two graphite grains, whose isotopic ratios point toward

a nova origin: low 12C/13C and 14N/15N ratios, high 30Si/28Si, and

close-to-solar 29Si/28Si. 26Al/27Al and 22Ne/20Ne ratios have been

determined for some of these grains, with values compatible with

nova model predictions. (

But...But...

Can nova explosions lead to Ti synthesis? Can nova explosions lead to Ti synthesis?

Yes, if we manage to produce slightly more violent outbursts:

* Explosions in lower L (colder) WDs or in low-accretion rate

episodes: José & Hernanz 2007, Meteor. & Planet. Sci., in press

* Primordial novae: José, García-Berro, Hernanz, & Gil-Pons

2007, ApJL, in press

Yes, if we manage to produce slightly more violent outbursts:

* Explosions in lower L (colder) WDs or in low-accretion rate

episodes: José & Hernanz 2007, Meteor. & Planet. Sci., in press

* Primordial novae: José, García-Berro, Hernanz, & Gil-Pons

2007, ApJL, in press

A new type of explosion,

halfway between a Nova

and a Supernova!_________

primordial

10

Primordial Novae: the First Nova ExplosionsPrimordial Novae: the First Nova Explosions

Primordial Novae = Nova-like, stellar explosions on white dwarfs

evolved in a cataclysmic primordial binary (Zzams ~ 0).

Primordial Novae = Nova-like, stellar explosions on white dwarfs

evolved in a cataclysmic primordial binary (Zzams ~ 0).

Solar [Fe/H] = -5.3

José, García-Berro, Hernanz, & Gil-Pons (2007) José, García-Berro, Hernanz, & Gil-Pons (2007)

11

Jordi JoséJordi José

NucleosynthesisNucleosynthesis in in Classical Novae Classical Novae XIX Rencontres de Blois “Matter and Energy in the Universe: from Nucleosynthesis

to Cosmology”, Château Royal de Blois, France, May 20-25, 2007

Margarita Hernanz, Jordi Gómez-Gomar

(IEEC, Barcelona)

Enrique García-Berro, Pilar Gil-Pons

(UPC, Barcelona)

Alain Coc (CSNSM, Orsay)

Christian Iliadis (UNC, Chapel Hill)

Sachiko Amari, Ernst Zinner, Katharina

Lodders (WUSL, St. Louis)

Steve Shore (Univ. Pisa)

Margarita Hernanz, Jordi Gómez-Gomar

(IEEC, Barcelona)

Enrique García-Berro, Pilar Gil-Pons

(UPC, Barcelona)

Alain Coc (CSNSM, Orsay)

Christian Iliadis (UNC, Chapel Hill)

Sachiko Amari, Ernst Zinner, Katharina

Lodders (WUSL, St. Louis)

Steve Shore (Univ. Pisa)