Systematic Features of CCSN neutrinos Ko Nakamura (Fukuoka Univ.) - PowerPoint PPT Presentation

Systematic Features of CCSN neutrinos Ko Nakamura (Fukuoka Univ.) T. Takiwaki (NAOJ) , S. Horiuchi (Virginia Tech.), M. Tanaka (Tohoku Univ.), K. Kotake (Fukuoka Univ.) International Symposium on Revealing the history of the universe with underground particle and nuclear research @ Tohoku Univ. Mar. 7-9, 2019

How to create a Core-collapse SN (CCSN) Final stage of a Supernova massive star H,He He C,O � Ne,Mg Si Fe Basic equations � Ø Neutrino from SN 1987A d ρ dt + ρ ∇ · v = 0 , ρ d v dt = −∇ P − ρ ∇ Φ , ∂ e ∗ ∂ t + ∇ · [( e ∗ + P ) v ] = − ρ v · ∇ Φ + Q E , dY e Energy and electron fraction change dt = Γ N , due to neutrino interactions. � EOS. △ Φ = 4 π G ρ ,

Explosion mechanism of CCSN � • Core-collapse supernova – Final fate of massive stars � >~10Mo � – Unclear mechanism of explosion Shock � – Neutrino heating mechanism – Convection, SASI Entropy � R [km] Bounce and Shock Formation $ $ 2 o ) (t ~ 0.11s, < c % R Fe R Fe radius of Density � ! e shock PNS � formation Si ~ 10 ~ 10 ! e Fe, Ni ! e (Janka+’06) � M(r) [M ] 0.5 1.0 nuclear matter nuclei $ $ ( & ) > ex.) % Si − burning shell M = 17 Mo ν e + n → p + e - , ν e + p → n + e + , etc. � Z = Zo �

Explosion mechanism of CCSN � • Core-collapse supernova – Final fate of massive stars � >~10Mo � – Unclear mechanism of explosion Convective – Neutrino heating mechanism motions � – Convection, SASI Entropy � R [km] Bounce and Shock Formation $ $ 2 o ) (t ~ 0.11s, < c % R R Fe Fe radius of Density � ! e shock Spherical inflow � formation Si ~ 10 ~ 10 ! e Fe, Ni ! e Mixing � (Janka+’06) � M(r) [M ] 0.5 1.0 nuclear matter nuclei $ $ ( & ) > ex.) % Si − burning shell M = 17 Mo ν e + n → p + e - , ν e + p → n + e + , etc. � Z = Zo �

Explosion mechanism of CCSN � • Core-collapse supernova Development of SASI – Final fate of massive stars � >~10Mo � – Unclear mechanism of explosion – Neutrino heating mechanism – Convection, SASI Entropy � R [km] Bounce and Shock Formation $ $ 2 o ) (t ~ 0.11s, < c % R Fe R Fe radius of Density � ! e shock formation Si ~ 10 ~ 10 ! e Fe, Ni ! e (Janka+’06) � M(r) [M ] 0.5 1.0 nuclear matter nuclei $ $ ( & ) > ex.) % Si − burning shell M = 17 Mo ν e + n → p + e - , ν e + p → n + e + , etc. � Z = Zo �

Explosion mechanism of CCSN � Neutrino transport from interior of PNS to outside of the shock • Core-collapse supernova Energy distribution – Final fate of massive stars � >~10Mo � to solve energy-dependent reactions � – Unclear mechanism of explosion – Neutrino heating mechanism – Convection, SASI Entropy � / 2D / R [km] Bounce and Shock Formation $ $ 2 o ) (t ~ 0.11s, < with appropriate resolution c % R R Fe Fe radius of Density � ! e shock formation Si ~ 10 ~ 10 ! e Fe, Ni ! e (Janka+’06) � M(r) [M ] 0.5 1.0 nuclear matter nuclei $ $ ( & ) > ex.) % Si − burning shell M = 17 Mo ν e + n → p + e - , ν e + p → n + e + , etc. � Z = Zo �

Time evolution of neutrino luminosity ü Showing 101 models with solar metallicity. The other models with lower metallicity have a similar trend (not shown here). ü The difference of L ν is more than double . 2-6 � 10 52 erg/s @ t = 200 ms. ZAMS mass [ M ⊙ ] ZAMS mass [ M ⊙ ] 8 40.0 8 40.0 ν e ν e neutrino luminosity [10 52 erg/s] neutrino luminosity [10 52 erg/s] 6 6 30.0 30.0 4 4 20.0 20.0 2 2 � smoothed over Δt = 20 ms. 0 10.0 0 10.0 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 time after bounce [s] time after bounce [s]

Compactness parameter What determines the CCSN properties is ... (*Not too much) Mass accretion � mass accretion onto the PNS! →PNS mass � → n luminosity � →Explosion energy � * Too much accretion leads to BH formation and/or failed explosion. → 56 Ni mass � 3.0 Compactness parameter ξ 1.5,cb compactness parameter ξ M (O’Connor & Ott ’11) 3 × ξ 2.0 3 × ξ 2.5 M/ M ⊙ 2.0 ξ ≡ R ( M ) / 1000km 1.0 0.0 10 15 20 25 30 35 40 ZAMS mass [ M ⊙ ]

Time evolution of neutrino luminosity ü Showing 101 models with solar metallicity. The other models with lower metallicity have a similar trend (not shown here). ü The difference of L ν is more than double . Compactness parameter 2-6 � 10 52 erg/s @ t = 200 ms. � O’Connor & Ott 2011 � M/M ⊙ ü The compactness-colored lines show a R ( M ) / 1000km . ξ M ≡ monotonic trend . ZAMS mass [ M ⊙ ] ZAMS mass [ M ⊙ ] 8 ξ 2.5 8 ξ 2.5 8 40.0 8 40.0 ν e ν e 0.4 0.4 neutrino luminosity [10 52 erg/s] neutrino luminosity [10 52 erg/s] neutrino luminosity [10 52 erg/s] neutrino luminosity [10 52 erg/s] 6 6 6 6 0.3 0.3 30.0 30.0 4 4 4 4 0.2 0.2 20.0 20.0 2 2 2 2 0.1 0.1 � smoothed over Δt = 20 ms. 0 10.0 0 10.0 0 0.0 0 0.0 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 time after bounce [s] time after bounce [s] time after bounce [s] time after bounce [s]

CCSN properties as a function of the compactness e-neutrino lumi. [10 52 erg/s] e-neutrino lumi. [10 52 erg/s] 2.2 2.2 4.5 4.5 remnant mass [ M ⊙ ] remnant mass [ M ⊙ ] 2.0 2.0 4.0 4.0 1.8 1.8 1.6 1.6 3.5 3.5 1.4 1.4 3.0 3.0 1.2 1.2 10 15 20 25 30 35 40 0.0 0.2 0.4 0.6 0.8 0.0 10 15 0.2 20 25 0.4 30 0.6 35 40 0.8 ZAMS mass [ M ⊙ ] compactness parameter ξ 2.0 compactness parameter ξ 2.0 ZAMS mass [ M ⊙ ] explosion energy [10 51 erg] explosion energy [10 51 erg] 0.8 0.8 6.0 6.0 nickel mass [10 -2 M ⊙ ] nickel mass [10 -2 M ⊙ ] 0.6 0.6 4.0 4.0 0.4 0.4 2.0 2.0 0.2 0.2 0.0 10 15 0.2 20 25 0.4 30 0.6 35 40 0.8 0.0 10 15 0.2 20 25 0.4 30 0.6 35 40 0.8 compactness parameter ξ 2.0 ZAMS mass [ M ⊙ ] compactness parameter ξ 2.0 ZAMS mass [ M ⊙ ]

Compilation of CCSNe Simulations for 101 Solar-metallicity Progenitors @t=t 400 @t=t fin. dia. [10 51 erg s -1 ] 1.6 (a) (d) 0.3 ⑤ . s -1 ] ① High neutrino luminosity results in 1.2 Compact progenitor suffers from 0.2 [M o an energetic explosion. high mass accretion rate, 0.8 0.1 M . E 0.4 . 5.0 L ν e [10 52 erg s -1 ] 2.5 (b) (e) . ] ③ M PNS [M o ④ .. and leaves a massive remnants 4.0 Accreted matter releases grav. energy 2.0 at the center. which is carried away by neutrinos. 3.0 1.5 800 . ] 4.0 (c) (f) M Ni [10 -2 M o ⑥ ② t 400 [ms] 600 3.0 so that it takes longer time Strong shock heating produces 400 to revive a stalled shock ejecta rich in nickel. 2.0 200 1.0 0.0 0.1 0.2 0.3 0.4 0.0 0.1 0.2 0.3 0.4 KN+’15, PASJ compactness parameter ξ 2.5

Neutrino signals & detectors ü Water-Cherenkov detector - Super Kamiokande (-Gd) - Hyper Kamiokande ü Reaction channels - inverse beta decay - electron scattering Gd-loaded SK can drastically suppress the background noise ( Beacom & Vagins '04 ). "Delayed coincidence"

Neutrino signals & detectors ZAMS mass [ M ⊙ ] ü Water-Cherenkov detector 8 40.0 ν e - Super Kamiokande (-Gd) - Hyper Kamiokande neutrino luminosity [10 52 erg/s] 6 30.0 ü Reaction channels 4 - inverse beta decay - electron scattering 20.0 2 ü Observed event rate: 0 10.0 0 0.1 0.2 0.3 0.4 0.5 time after bounce [s] Number of targets

Galactic event @ 8.5 kpc ü Water-Cherenkov detector - Super Kamiokande (-Gd) s17.0 - Hyper Kamiokande ü Reaction channels - inverse beta decay - electron scattering KN+’16, MNRAS ü Observed event rate: ü Timing information (via IBD): the bounce time within � 3.0 ms (HK) at 95% confidence level. Number of targets ü Pointing information (via e - scattering): ~ 6˚ (SK), ~ 3˚ (SK-Gd), ~ 2˚ (HK) ~ 0.6 � (HK-Gd)

Probability (%) 9.8% 15.6% 15.5% 13.5% 11.5% 9.4% 7.4% Field of views (FOV) of optical telescopes 15 10 5 KN+’16, MNRAS 1.2% 16.1% 0 Naked eye 1-2m 4m >8m Evryscope 100 FOV diameter (deg) 10 ASAS-SN SK ZTF SK-Gd LSST Pan-STARRS Blanco Subaru 1 CFHT 0.1 -5 0 5 10 15 20 25 30 ←bright Optical magnitude dark→

Time sequence of observations (pre-SN neutrino) Red Supergiant (RSG) progenitor Wolf-Rayet (WR) progenitor → Type II SN → Type Ib/c SN neutrino burst R* ~ 10 13-14 cm, shock velocity ~ 10 9 cm/s R* ~ 10 11 cm → Δt ~ R*/v ~ 10 4-5 s (a few hours - a day) → Δt ~ R*/v ~ 100 s (a few minutes) ! Distribute ALERT ! (SN Early Warning System; SNEWS) SBO Smith+’11, MNRAS

Pinning down the progenitor compactness Template of neutrino light curves Expected detection events from numerical simulations KN+’16, MNRAS 8 ξ 2.5 ν e 40 0.4 140 Electron scattering Events per 2ms 30 Inverse-beta decay Events @ HK [per 1ms bin] neutrino luminosity [10 52 erg/s] 120 8.5 kpc 20 6 10 0.3 100 0 0 10 20 30 40 t pb [ms] 80 4 0.2 60 40 2 0.1 20 0 0.001 0.01 0.1 1 10 Post-bounce time [s] 0 0.0 0 0.1 0.2 0.3 0.4 0.5 time after bounce [s]