r-Process nucleosynthesis in neutron star mergers and GW170817 - PowerPoint PPT Presentation

r-Process nucleosynthesis in neutron star mergers and GW170817 Jonas Lippuner July 18, 2018 FRIB and the GW170817 Kilonova FRIB/NSCL/MSU, East Lansing MI Operated by Los Alamos National Security, LLC for the U.S. Department of Energy’s NNSA Los Alamos National Laboratory UNCLASSIFIED LA-UR-18-21867

Outline 1. r-Process nucleosynthesis overview 2. r-Process in neutron star mergers 3. Observational signature and first detection Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 2

Solar system abundances Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 3

Solar system abundances Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 3

The s-process slow neutron capture 90Zr 91Zr 92Zr τ β − ≪ τ n ∼ 10 2 − 10 5 yr 89Y 84Sr 86Sr 87Sr 88Sr 85Rb 87Rb 78Kr 80Kr 82Kr 83Kr 84Kr 86Kr 79Br 81Br 74Se 76Se 77Se 78Se 80Se 82Se 75As 70Ge 72Ge 73Ge 74Ge 76Ge 69Ga 71Ga 66Zn 67Zn 68Zn 70Zn 65Cu closed neutron shell Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 4

The s-process slow neutron capture 90Zr 91Zr 92Zr τ β − ≪ τ n ∼ 10 2 − 10 5 yr 89Y 84Sr 86Sr 87Sr 88Sr 85Rb 87Rb 78Kr 80Kr 82Kr 83Kr 84Kr 86Kr 79Br 81Br 74Se 76Se 77Se 78Se 80Se 82Se 75As 70Ge 72Ge 73Ge 74Ge 76Ge 69Ga 71Ga 66Zn 67Zn 68Zn 70Zn 65Cu closed neutron shell Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 4

The r-process rapid neutron capture 90Zr 91Zr 92Zr τ n ≪ τ β − ∼ 10 ms – 10 s 89Y 84Sr 86Sr 87Sr 88Sr 85Rb 87Rb 78Kr 80Kr 82Kr 83Kr 84Kr 86Kr 79Br 81Br 74Se 76Se 77Se 78Se 80Se 82Se 75As 70Ge 72Ge 73Ge 74Ge 76Ge 69Ga 71Ga 66Zn 67Zn 68Zn 70Zn 65Cu neutron drip line closed neutron shell Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 5

The r-process rapid neutron capture 90Zr 91Zr 92Zr τ n ≪ τ β − ∼ 10 ms – 10 s 89Y 84Sr 86Sr 87Sr 88Sr 85Rb 87Rb 78Kr 80Kr 82Kr 83Kr 84Kr 86Kr 79Br 81Br 74Se 76Se 77Se 78Se 80Se 82Se 75As 70Ge 72Ge 73Ge 74Ge 76Ge 69Ga 71Ga 66Zn 67Zn 68Zn 70Zn 65Cu neutron drip line closed neutron shell Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 5

Double peaks due to closed neutron shells s-process: τ β − ≪ τ n ∼ 10 2 − 10 5 yr 90Zr 91Zr 92Zr r-process: τ n ≪ τ β − ∼ 10 ms – 10 s 89Y 84Sr 86Sr 87Sr 88Sr 85Rb 87Rb 78Kr 80Kr 82Kr 83Kr 84Kr 86Kr 79Br 81Br 74Se 76Se 77Se 78Se 80Se 82Se 75As 70Ge 72Ge 73Ge 74Ge 76Ge 69Ga 71Ga 66Zn 67Zn 68Zn 70Zn 65Cu neutron drip line closed neutron shell Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 6

Double peaks due to closed neutron shells s-process: τ β − ≪ τ n ∼ 10 2 − 10 5 yr 90Zr 91Zr 92Zr r-process: τ n ≪ τ β − ∼ 10 ms – 10 s 89Y 84Sr 86Sr 87Sr 88Sr 85Rb 87Rb 78Kr 80Kr 82Kr 83Kr 84Kr 86Kr 79Br 81Br 74Se 76Se 77Se 78Se 80Se 82Se 75As 70Ge 72Ge 73Ge 74Ge 76Ge 69Ga 71Ga 66Zn 67Zn 68Zn 70Zn 65Cu neutron drip line closed neutron shell Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 6

Double peaks due to closed neutron shells s-process: τ β − ≪ τ n ∼ 10 2 − 10 5 yr 90Zr 91Zr 92Zr r-process: τ n ≪ τ β − ∼ 10 ms – 10 s 89Y 84Sr 86Sr 87Sr 88Sr 85Rb 87Rb 78Kr 80Kr 82Kr 83Kr 84Kr 86Kr 79Br 81Br 74Se 76Se 77Se 78Se 80Se 82Se 75As 70Ge 72Ge 73Ge 74Ge 76Ge 69Ga 71Ga 66Zn 67Zn 68Zn 70Zn 65Cu neutron drip line closed neutron shell Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 6

Double peaks due to closed neutron shells s-process: τ β − ≪ τ n ∼ 10 2 − 10 5 yr 90Zr 91Zr 92Zr r-process: τ n ≪ τ β − ∼ 10 ms – 10 s 89Y 84Sr 86Sr 87Sr 88Sr 85Rb 87Rb 78Kr 80Kr 82Kr 83Kr 84Kr 86Kr 79Br 81Br 74Se 76Se 77Se 78Se 80Se 82Se 75As 70Ge 72Ge 73Ge 74Ge 76Ge 69Ga 71Ga 66Zn 67Zn 68Zn 70Zn 65Cu neutron drip line closed neutron shell Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 6

Solar system abundances Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 7

SkyNet Sky Net b i t b u c k e t . o r g / j l i p p u n e r / s k y n e t • General-purpose nuclear reaction network • ∼ 8000 isotopes, ∼ 140,000 nuclear reactions • Evolves temperature based on nuclear reactions • Input: ρ ( t ) , initial composition, entropy • Open source Lippuner, J. and Roberts, L. F., ApJS 233, 18 (2017) Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 8

SkyNet features Science • Extended Timmes equation of state (EOS) • Calculate nuclear statistical equilibrium (NSE) • NSE evolution mode • Calculate inverse rates from detailed balance to be consistent with NSE • Electron screening with smooth transition between weak and strong screening (reactions and NSE) Code • Adaptive time stepping • Python bindings • Modularity • Extendible reaction class (currently REACLIB, table, neutrino) • Make movies Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 9

Outline 1. r-Process nucleosynthesis overview 2. r-Process in neutron star mergers 3. Observational signature and first detection Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 10

Merger ejecta: Dynamical Tidal tails or collision interface NS–NS: M ej ∼ 10 − 4 − few × 10 − 2 M ⊙ , Y e ∼ 0 . 05 − 0 . 45 NS–BH: M ej ∼ 0 − 10 − 1 M ⊙ , Y e � 0 . 2 Bauswein+13, Hotokezaka+13, Foucart+14, Sekiguchi+15, Kyutoku+15, Radice+16 From Price+06 From Bauswein+13 Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 11

Merger ejecta: Disk outflow Neutrino driven wind or outflow due to viscous heating and α recombination M ej ∼ few × 10 − 3 M ⊙ , Y e ∼ 0 . 2 − 0 . 45 Surman+08, Wanajo+11, Fern´ andez+13, Perego+14, Just+15, Foucart+15 From Perego+14 From Fern´ andez+13 Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 12

Movie http://jonaslippuner.com/skynet/SkyNet_Ye_0.010_s_010.000_tau_007.100.mp4 http://jonaslippuner.com/skynet/SkyNet_Ye_0.250_s_010.000_tau_007.100.mp4 Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 13

r-Process abundances vs. electron fraction 10 − 2 Y e = 0 . 01 Observed solar r-process Y e = 0 . 19 10 − 3 Y e = 0 . 25 Y e = 0 . 50 10 − 4 Abundance 10 − 5 10 − 6 10 − 7 10 − 8 10 − 9 0 25 50 75 100 125 150 175 200 225 250 Mass number A JL, Roberts 2015, ApJ 815, 82, arXiv:1508.03133 Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 14

Full binary neutron star merger simulations From Wanajo+14 From Wanajo+14 See also Goriely+15 Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 15

Nucleosynthesis in HMNS disk outflow • 3 M ⊙ central HMNS or BH, 0 . 03 M ⊙ accretion disk • Variable HMNS lifetime, neutrino leakage, α viscosity Figure from Metzger & Fern´ andez (2014) Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 16

Final abundances 10 − 2 Observed solar r-process 10 − 3 Final abundance M ej Y A 10 − 4 10 − 5 10 − 6 10 − 7 τ = 0 ms τ = 100 ms τ = 10 ms τ = 300 ms 10 − 8 τ = 30 ms τ = ∞ 10 − 9 0 25 50 75 100 125 150 175 200 225 250 Mass number A JL, Fern´ andez, Roberts, et al. 2017, MNRAS 472, 904, arXiv:1703.06216 Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 17

Black hole–neutron star merger Roberts, JL, Duez, et al. 2017, MNRAS 464, 3907, arXiv:1601.07942 1. Full GR simulation of BH–NS Francois Foucart (UNH), Foucart et al. , Phys. Rev. D 90, 024026 (2014) 2. Evolve ejecta in SPH code Matt Duez (WSU) 3. Nucleosynthesis with varying neutrino luminosity JL and Luke Roberts (MSU) Figure credit: F. Foucart Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 18

BHNS: Final abundances vs. neutrino luminosity 10 − 2 L ν e , 52 = 0 . 2 L ν e , 52 = 25 L ν e , 52 = 1 Solar r-process 10 − 3 Relative final abundance 10 − 4 10 − 5 10 − 6 10 − 7 10 − 8 0 50 100 150 200 250 Mass number A Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 19

Neutrino driven wind in core-collapse supernovae • Neutrinos emitted from hot proto-neutron star can drive outflow of n and p • Neutrino driven wind is mildly neutron-rich → r-process? Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 20

Jet in MHD-driven supernova • Requires very high magnetic field ( B ∼ 10 12 − 10 13 G) and rapid rotation • Maybe 0 . 1 − 1% of all core-collapse supernovae Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 21

Jet in MHD-driven supernova Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 22

Outline 1. r-Process nucleosynthesis overview 2. r-Process in neutron star mergers 3. Observational signature and first detection Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 23

Observational signature of r-process: Kilonova Metzger & Berger, 2012, ApJ 746, 48 Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 24

Impact of lanthanides 10 − 2 10 − 2 Y e = 0 . 01 Observed solar r-process Y e = 0 . 19 Lanthanides Y e = 0 . 25 Actinides 10 − 3 10 − 3 Y e = 0 . 50 10 − 4 10 − 4 Abundance Abundance 10 − 5 10 − 5 10 − 6 10 − 6 10 − 7 10 − 7 10 − 8 10 − 8 10 − 9 10 − 9 0 0 25 25 50 50 75 75 100 100 125 125 150 150 175 175 200 200 225 225 250 250 Mass number A Mass number A Los Alamos National Laboratory UNCLASSIFIED 3/19/2018 | 25