From supernovae to neutron stars Yudai Suwa 1,2 1 Yukawa Institute - PowerPoint PPT Presentation

From supernovae to neutron stars Yudai Suwa 1,2 1 Yukawa Institute for Theoretical Physics, Kyoto University 2 Max Planck Institute for Astrophysics, Garching

Introduction: what is supernova? Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 2 /25

Supernova before after SN 2011fe

Supernovae make neutron stars Baade & Zwicky 1934 Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 4 /25

Key observables characterizing supernovae Explosion energy: ~10 51 erg =10 44 J measured by fj tting Ejecta mass: ~ M ⦿ =1.989 × 10 30 kg SN light curves Ni mass: ~0.1M ⦿ measured by NS mass: ~1 - 2M ⦿ binary systems fj nal goal of fj rst-principle ( ab initio ) simulations Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 5 /25

Fe Standard scenario of core-collapse supernovae Final phase of stellar Neutron star formation Neutrinosphere formation evolution (core bounce ） （ neutrino trapping ） Neutron Fe Neutrinosphere Star Si O,Ne,Mg C+O HeH ρ c ~10 14 g cm -3 ρ c ~10 11 g cm -3 ρ c ~10 9 g cm -3 shock stall shock revival Supernova! HOW? NS Si O,Ne,Mg C+O HeH Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 6 /25

Current paradigm: neutrino-heating mechanism heating region shock cooling region absorption neutron staremission Energy is transferred by neutrinos Most of them are just escaping from the system, but are partially absorbed In gain region, neutrino heating overwhelms neutrino cooling Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 7 /25

Numerical simulations Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 8 /25

Physical ingredients In these violent explosions, all known interactions are involving and playing important roles; Strong Weak - nuclear equation of state - neutrino interactions σ ν ~10 -44 cm 2 (E ν /m e c 2 ) 2 - structure of neutron stars R NS ~10-15 km - ~99% of energy is emitted by ν ’s max(M NS )> 2 M ⊙ - cooling of proto-neutron star - nucleosynthesis - heating of postshock material Electromagnetic Gravitational - energy budget - Coulomb collision of p and e E G ~3.1x10 53 erg(M/1.4M ⊙ ) 2 (R/10km) -1 - fj nal remnants are ~0.17M ⊙ c 2 pulsars ( B~10 12 G) - inducing core collapse magnetars ( B~10 14-15 G) - making general relativistic objects magnetic fj elds a fg ect dynamics (NS/BH) Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 9 /25

What do simulations solve? Numerical Simulations Hydrodynamic equations Neutrino Boltzmann d ρ equation dt + ρ ∇ · v = 0 , Solve 1 − µ 2 � ∂ f � � d ln ρ � � � cdt + µ ∂ f df + 3 v + 1 ρ d v ∂ r + µ simultaneously cdt cr r ∂ µ dt = −∇ P − ρ ∇ Φ , � � d ln ρ � � + 3 v − v E ∂ f µ 2 + cdt cr cr ∂ E de ∗ e ∗ + P �� � � dt + ∇ · = − ρ v · ∇ Φ + Q E , E 2 v = j (1 − f ) − χ f + c ( hc ) 3 dY e � � � � Rf ′ dµ ′ − f dt = Q N , � 1 − f ′ � dµ ′ (1 − f ) R . × △ Φ = 4 π G ρ , ρ : density , v : velocity , P : pressure , Φ : grav. f : neut. dist. func, µ : cos θ , E : neut. energy, potential, e * : total energy, Y e : elect. frac., j : emissivity, χ : absorptivity, R : scatt. Q : neutrino terms kernel Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 10 /25

1D simulations fail to explode Rammp & Janka 00 Liebendörfer+ 01 By including all available physics to simulations, we concluded that the explosion cannot be obtained in 1D! (The exception is an 8.8 M ⦿ star; Kitaura+ 06) Thompson+ 03 Sumiyoshi+ 05 Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 11 /25

Neutrino-driven explosion in multi-D simulation We have exploding models driven by neutrino heating with 2D/3D simulations [Suwa+ PASJ, 62 , L49 (2010); ApJ, 738 , 165 (2011); ApJ 764 , 99 (2013); PASJ, 66 , L1 (2014); arXiv:1406.6414] comparison between 1D and 2D entropy [k B /baryon] Müller, Janka, Marek (2012) Brruenn et al. (2013) 800 ms 6000 3000 0 3000 6000 -9000 -6000 -3000 0 3000 6000 9000 ymmetry axis [km] Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 12 /25

Dimensionality and numerical simulations ※ grid-based codes only, not completed Only simulations in this region can judge the neutrino-driven explosion scenario Dimension Blondin+, 07 Iwakami+, 08 Takiwaki, Kotake, & Suwa, 12 3D Mikami+, 08 Hanke+, 13 Scheidegger+, 08 Lentz+, 15 Nordhaus+, 10 Hanke+, 12 Müller, 15 Couch, 13 Handy+, 14 2D Kotake+, 03 Burrows+, 06 Yamada & Sato, 94 (axial-sym.) Buras+, 06 Blondin & Mezzacappa, 03 Ohnishi+, 06 Ott+, 08 Obergaulinger+, 06 Murphy+, 08 Suwa+, 10 Takiwaki+, 09 Müller+, 12 Sekiguchi+, 11 Bruenn+, 13 Obergaulinger+,14 Pan+, 15 1D Rampp & Janka, 00 (spherical-sym.) Liebendörfer+, 01 Thompson+, 03 Sumiyoshi+, 05 O’Connor+, 13 Transport cooling only Adiabatic or Neutrino Treatment ��������������������������������������������������������� heat by hand Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 13 /25

3D simulation with spectral neutrino transfer [Takiwaki, Kotake, Suwa, ApJ, 749 , 98 (2012); ApJ, 786 , 83 (2014)] M ZAMS =11.2 M ⊙ 384(r)x128( θ )x256( φ )x20(E ν ) XT4 T2K-Tsukuba K computer Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 14 /25

Dimensionality and initial perturbation [Takiwaki, Kotake, Suwa, ApJ, 786 , 83 (2014)] 2D 3D 1D Note) explosion energy is still too small ( ~10 50 erg) compared to observations ( ~10 51 erg) Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 15 /25

Equation of state dependence Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 16 /25

List of SN EOS Courtesy of M. Hempel Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 17 /25

Finite temperature EOSs Lattimer & Swesty (LS) (1991) Hillebrandt & Wol fg (1985) based on compressible liquid drop model Hartree-Fock calculation G.Shen et al. (2010, 2011) variants with K=180, 220, and 375 MeV relativistic mean fj eld theory (NL3, FSUGold) H.Shen et al. (1998, 2011) Hempel et al. (2012) relativistic mean fj eld theory (TM1, TMA, FSUGold) relativistic mean fj eld theory (TM1) More recently, Steiner+ (2013), Furusawa+ (2013), etc. including hyperon component (~2011) incompressibility symmetry energy slope of symmetry energy K [MeV] J (S) [MeV] L [MeV] LS 180, 220, 375 29.3 --- HShen 281 36.9 111 HW 263 32.9 --- 271.5 (NL3) 37.29 (NL3) 118.2 (NL3) GShen 230.0 (FSU) 32.59 (FSU) 60.5 (FSU) [Fischer, Hempel, Sagert, Suwa, Scha fg ner- 318 (TMA) 30.7 (TMA) 90 (TMA) Hempel Bielich, EPJA, 50 , 46 (2014)] 230 (FSU) 32.6 (FSU) 60 (FSU) Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 18 /25

Shock radius evolution depending on EOS [Suwa, Takiwaki, Kotake, Fischer, Liebendörfer, Sato, ApJ, 764 , 99 (2013)] maximum average minimum LS180 and LS375 succeed the explosion HShen EOS fails Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 19 /25

Radius of neutron star [Suwa, Takiwaki, Kotake, Fischer, Liebendörfer, Sato, ApJ, 764 , 99 (2013)] 100 LS180 LS375 Radius of Neutron Star [km] Shen 90 Faster contraction is better for the 80 explosion! 70 60 50 0 100 200 300 400 500 600 500 km 1000 km Time after Bounce [ms] → 5000 km Pressure perturbation Radius Time Radius Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 20 /25

From supernovae to neutron stars Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 21 /25

From SN to NS-1 [Suwa, Takiwaki, Kotake, Fischer, Liebendörfer, Sato, ApJ, 764 , 99 (2013); Suwa, PASJ, 66 , L1 (2014)] entropy [k B /baryon] ejecta NS mass ~1.3 M � NS Progenitor: 11.2 M ⊙ (Woosley+ 2002) Successful explosion! (but still weak with E exp ~10 50 erg) The mass of NS is ~1.3 M ⊙ The simulation was continued in 1D to follow the PNS cooling phase up to ~70 s p.b. Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 22 /25

From SN to NS-2 [Suwa, PASJ, 66 , L1 (2014)] ν Crust formation! Z=50 Γ xThermal energy (C)NASA = Coulomb energy Z=70 Z=26 Γ ≡ ( Ze ) 2 rk B T = Coulomb energy Thermal energy ∼ 200 Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 23 /25

Implications Crust formation time should depend on EOS (especially symmetry energy?) We may observe crust formation via neutrino luminosity evolution Cross section of neutrino scattering by heavier nuclei or pasta is much larger than that of neutrons and protons Neutrino luminosity may suddenly drop when we have heavier nuclei! Magnetar (large B- fj eld NS) formation competitive process between crust formation and magnetic fj eld escape from NS Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 24 /25

Summary Supernova explosions by neutrino-heating mechanism have become possible Consistent modeling from iron cores to (cold) neutron stars (i.e. until NS crust formation) is doable now related to neutrino observations, magnetar formation, NS pasta, nuclear EOS... Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 25 /25

Announcement A long-term workshop at Yukawa Institute for Theoretical Physics in Kyoto University “Nuclear Physics, Compact Stars, and Compact-star Mergers” (NPCSM2016) Oct. 17 (Mon.) -- Nov. 18 (Fri.), 2016 Please join us! Yudai Suwa, NUFRA2015 @ Kemer, Turkey 6/10/2015 26 /25