NICXII, July Pre-SN Evolution & Nucleosynthesis in. Massive Stars. & Key Nuclear Physics Uncertainties. Raphael HIRSCHI

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NICXII, July 2012 Pre-SN Evolution & Nucleosynthesis in Massive Stars & Key Nuclear Physics Uncertainties Raphael HIRSCHI in collaboration with: G. Meynet, A. Maeder, S. Ekström (Geneva, CH), C.

1 NICXII, July 2012 Pre-SN Evolution & Nucleosynthesis in Massive Stars & Key Nuclear Physics Uncertainties Raphael HIRSCHI in collaboration with: G. Meynet, A. Maeder, S. Ekström (Geneva, CH), C. Georgy (Lyon, F) and C. Chiappini (IAP, D) F.-K. Thielemann, U. Frischknecht, T. Rauscher, M. Pignatari (Basel, CH) P. Crowther (Sheffield), O. Schnurr (IAP), N. Yusof, H. Kassim (Uni. Malaya, KL, Malaysia) M. Bennett, S. Jones (Keele, UK), K. Nomoto, T. Suda (IPMU, J), T. Fischer (TUD, D) NUGRID: F. Herwig (Victoria, Canada), LANL MESA: B. Paxton (KITP), F. X. Timmes, Arizona (US)

2 Plan - Introduction + physics ingredients - Boosted s process in low-z rotating massive stars - Key recent nuclear physics uncertainties/studies: - 17O(, ), 26Al, 3,12C(, ),12C-12C, weak rates - Conclusions & outlook

3 Massive Stars Massive stars: M > 8 solar masses Main sequence: hydrogen burning WR After Main Sequence: LBV BSG RSG MS Helium burning Supergiant stage (red or blue) Wolf-Rayet (WR): M > Mo WR without RSG: M > 40 Mo Advanced stages: carbon, neon, oxygen, silicon burning iron core Core collapse bounce supernova explosion 3 Raphael Hirschi Keele University (UK)

4 How massive can stars be? Do very massive stars (VMS: M>100Mo) exist? - Star formation: already difficulties with 30 Mo stars but 2/3D simulations are promising (Kuiper et al 11) - Stellar evolution: possible up to ~ 1,000 Mo (BUT mass loss/rad.) (Baraffe et al 01) Can we see them? - Rare and short-lived - Need to look at youngest and most massive clusters: - Arches: M<~150 Mo (Figer 05, Martins et al 08) - NGC 3603 & R136: new Mmax=320Mo! (Crowther et al 10, MNRAS) R136 cluster SEE TALK by Yoshida & POSTER 275 Yusof et al concerning fate

enhanced and anisotropic Mixing: meridional circ. & shear Mass loss dep.

5 Geneva Stellar Evolution Code 1.5D hydrostatic code (Eggenberger et al 2008) Ω Rotation: (Maeder & Meynet 2008) Centrifugal force Mass loss: enhanced and anisotropic Mixing: meridional circ. & shear Mass loss dep. on Z & Ω Convection: Schwarzschild HP Large+flexible nuclear reaction network: rates from NACRE/reaclib B-fields (Spruit 02, Maeder 05) SEE POSTER 269: Tout & Potter Models ZAMS until Silicon burning Meynet & Maeder 2000

6 Massive Stars: Evolution of the chemical composition Burning stages (lifetime [yr]): Hydrogen (106-7): 1H 4He & 12C, 16O 14N Helium (105-6): 4He 12C, 16O &14N 18O 22Ne Carbon (102-3):12C 20Ne, 24Mg Neon (0.1-1): 20Ne 16O, 24Mg Oxygen (0.1-1): 16O 28Si, 32S Silicon (10-3): 28Si, 32S 56Ni, 54,56Fe 6 Raphael Hirschi Keele University (UK)

7 What changes at low Z? Stars are more compact: R~R(Zo)/4 (lower opacities) at Z=10-8 Rotation at low Z: stronger shear, weaker mer. circ. Mass loss weaker at low Z: faster rotation M Z = M Z o Z/Z o - α = (Kudritzki & Puls 00, Ku02) (Nugis & Lamers, Evans et al 05) - α = (Vink et al 00,01,05) Z(LMC)~Zo/2.3 => Mdot/1.5 Mdot/2 Z(SMC)~Zo/7 => Mdot/2.6 - Mdot/5 Which elements dominate Mdot? O* & WR: Z dep. / Fe dom. & plateau at low Z for WR (Vink et al 05) CNO-driven wind at low Z for WR? Graefener & Hamann 08 RSG (and LBV?): no Z-dep.; CNO? (Van Loon 05)

8 Rotation induced low Z Before H-shell boost end of He burning Hirschi et al 07 --> s process??? Hirschi et al 08

9 S Process in Massive Stars Weak s process: (slow neutron capture process) during core He- and shell C-burning (T > 2.5 x 10 K) 8 Kaeppeler, et al, 2011, RvMP, 83, 157 N-source: 22Ne(a,n) Seed: iron Poisons: - He-b.: 22Ne, 16 O, 12 O, 20 Mg, C - C-b.: 24Mg, Mg, Ne At solar Z: rotating models may produce up to 3x more s process How much s process do massive rotating stars produce at low Z?

10 S Process in Massive Stars, Nuclear Physics Uncertainty Hirschi et al 2008, NICX Pignatari et al 08, ApJ letter, 687,95 O: poison or absorber? 16 Measurement of 17O(a,g)21Ne at TRIUMF 17 O(a,g) lower than CF88! Taggart et al NICXI: But higher than Descouvemont 1993! Best et al 2011 Notre Dame): TALK by Laird 10 Raphael Hirschi Keele University (UK)

11 New S Process Models of Massive Rotating Stars Z=10-5, rotating models with different 17O(a,g) rates; Vini Frischknecht et al, A&A letter 2011 STELLAR EVOLUTION CALCULATIONS WITH 600/700-ISOTOPE NETWORK! Ne production almost primary but still varies with Z & especially Vini. Mini Secondary seeds (Fe) limit production (22Ne cannot act as seed) Strong variations in [Sr,Y/Ba] up to 2 dex dep. on Z,V ini, and 17O(a,g) 22 Possibility of explosive n-capture process in He-shell

New S Process Models Compared to EMP * & Bulge GC Bulge GC * Chiappini et al, Nature Letter, 2011 EMP * Strong variations in [Y/Ba] >~ 2 dex matches well observed range!

12 New S Process Models Compared to EMP * & Bulge GC Bulge GC * Chiappini et al, Nature Letter, 2011 EMP * Strong variations in [Y/Ba] >~ 2 dex matches well observed range! (EMP *: Frebel et al 2010) New models also explain abundances in one of the oldest clusters in galactic bulge TALK by Cescutti Other processes cannot explain all the observed stars in bulge GC NGC6522

13 26 Al Production: sensitivity study by Illiadis et al 2011 ~70 rates studied! 1-zone trajectories (temp., density) for core H, shell C/Ne, expl. C/Ne Key uncertain rates (still uncertain & important for 26Al):

14 3, 12C(, ): sensitivity studies by Tur et al 07,09,10 Full stellar evolution models required! Impact on s process: Tur et al 07/09; 26Al, 60Fe, 44Ti Tur et al 10 Study shows important impact of these two rates Results affected by C/Ne/O shell mergers need for 3D simulations as in TALK by Stancliffe

15 Constraints from stellar evolution: 12C 12C rate, 3 Full stellar models + post-processing using MPPNP (Nugrid) Very high rate ruled out!! (Terrasi et al. 2007) Bennett et al 2011 See Suda et al 2011 for a study constraining 3 reaction

16 Massive/AGB Stars Transition 7-12 Mo models MESA stellar evolution code: Si-b. Ne-b. C-b. He-b. O-b. Massive??? SAGB (off-centre C-ign.) AGB (no C-b.) Jones et al in prep; see also Mueller et al 12, Umeda et al 12

17 Weak interaction rates Current rate tables (Oda et al 1994) are far too sparse!! 17 Raphael Hirschi Keele University (UK)

18 Conclusions Rotation changes low Z: Strong mixing between helium & hydrogen burning zones Large s process, primary 14N,13C prod. over entire Z range helps reproduce chem. comp. of EMP * & oldest bulge GC Multiple approaches used to produce sensitivity studies are very promising: - approx. evolution study many rates (Illiadis et al 2011) - full stellar models full impact of a few rates (energy generation) (Tur et al 07,09,10, Bennett et al 11, Suda et al 11) Weak rate tables need to be denser!

19 Stellar HYdrodynamics Nucleosynthesis & Evolution (SHYNE) Project ERC Starting grant: 5 year; 2 Postdocs; 2 PhDs; 1280-CPU cluster TOOL SUITE DATASETS Nuclear Physics: (FAIR, GSI) Priority List Monte Carlo INPUT IMPACT Post-processing Constraints Impact Studies Constraints Predictions Stellar Evolution Constraints INPUT + Constraints Constraints +New Prescriptions GRIDS of models Predictions Yields Progenitors 3D HYDRO Efficient pipeline: nuclear/hydro/astro Observations: GAIA-ESO survey GAIA satellite INPUT Gal. Chem. Evol. models Supernova Simulations

20 Keele is Not Kiel (Germany) But Where is it? West Midlands: Keele Keele area is famous for pottery: Wedgwood,... and football: Stoke city fc in premier league

FOE, Raleigh, May 13. SN Progenitors:

FOE, Raleigh, May 13. SN Progenitors: FOE, Raleigh, May 13 SN Progenitors: Evolution and Uncertainties Raphael HIRSCHI in collaboration with: SHYNE team @ Keele: C. Georgy, N. Nishimura, S. Jones, M. Bennett (Keele, UK) GVA code: G. Meynet,