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
International Symposium on Revealing the history of the universe with underground particle and nuclear research @ Tohoku Univ. Mar. 7-9, 2019
Ø Neutrino from SN 1987A
H,He He C,O Ne,Mg Si Fe
massive star
Basic equations EOS.
dρ dt + ρ∇ · v = 0, ρ dv dt = −∇P − ρ∇Φ, ∂e∗ ∂t + ∇ · [(e∗ + P)v] = −ρv · ∇Φ + QE, dYe dt = ΓN, △ Φ = 4πGρ,
Energy and electron fraction change due to neutrino interactions.
– Final fate of massive stars >~10Mo – Unclear mechanism of explosion – Neutrino heating mechanism – Convection, SASI
e
!
e
! !
e
Fe, Ni 0.5 1.0 Si R [km] M(r) [M ] Si−burning shell ( $
> %
$
&)
RFe
$
c
2
%
$
<
formation shock radius of ~ 10
Fe
R
Bounce and Shock Formation
nuclear matter ~ 10 nuclei
(t ~ 0.11s,
(Janka+’06)
νe + n → p + e-, νe + p → n + e+, etc. Entropy Density PNS Shock ex.) M = 17 Mo Z = Zo
– Final fate of massive stars >~10Mo – Unclear mechanism of explosion – Neutrino heating mechanism – Convection, SASI
e
!
e
! !
e
Fe, Ni 0.5 1.0 Si R [km] M(r) [M ] Si−burning shell ( $
> %
$
&)
RFe
$
c
2
%
$
<
formation shock radius of ~ 10
Fe
R
Bounce and Shock Formation
nuclear matter ~ 10 nuclei
(t ~ 0.11s,
(Janka+’06)
νe + n → p + e-, νe + p → n + e+, etc. Entropy Density Spherical inflow Convective motions Mixing ex.) M = 17 Mo Z = Zo
– Final fate of massive stars >~10Mo – Unclear mechanism of explosion – Neutrino heating mechanism – Convection, SASI
e
!
e
! !
e
Fe, Ni 0.5 1.0 Si R [km] M(r) [M ] Si−burning shell ( $
> %
$
&)
RFe
$
c
2
%
$
<
formation shock radius of ~ 10
Fe
R
Bounce and Shock Formation
nuclear matter ~ 10 nuclei
(t ~ 0.11s,
(Janka+’06)
νe + n → p + e-, νe + p → n + e+, etc. Entropy Density Development
ex.) M = 17 Mo Z = Zo
– Final fate of massive stars >~10Mo – Unclear mechanism of explosion – Neutrino heating mechanism – Convection, SASI
e
!
e
! !
e
Fe, Ni 0.5 1.0 Si R [km] M(r) [M ] Si−burning shell ( $
> %
$
&)
RFe
$
c
2
%
$
<
formation shock radius of ~ 10
Fe
R
Bounce and Shock Formation
nuclear matter ~ 10 nuclei
(t ~ 0.11s,
(Janka+’06)
νe + n → p + e-, νe + p → n + e+, etc. Neutrino transport from interior of PNS to outside of the shock Energy distribution to solve energy-dependent reactions /2D/ with appropriate resolution Entropy Density ex.) M = 17 Mo Z = Zo
ü Showing 101 models with solar metallicity. The other models with lower metallicity have a similar trend (not shown here). ü The difference of Lν is more than double. 2-6 1052 erg/s @ t = 200 ms. smoothed over Δt = 20 ms.
2 4 6 8 0.1 0.2 0.3 0.4 0.5 ZAMS mass [M⊙] neutrino luminosity [1052erg/s] time after bounce [s] 10.0 20.0 30.0 40.0 2 4 6 8 0.1 0.2 0.3 0.4 0.5 ZAMS mass [M⊙] neutrino luminosity [1052erg/s] time after bounce [s] 10.0 20.0 30.0 40.0
(*Not too much) Mass accretion →PNS mass →n luminosity →Explosion energy →56Ni mass Compactness parameter ξ ≡ M/ M⊙ R(M)/1000km
0.0 1.0 2.0 3.0 10 15 20 25 30 35 40 compactness parameter ξM ZAMS mass [M⊙]
ξ1.5,cb 3 × ξ2.0 3 × ξ2.5
(O’Connor & Ott ’11) What determines the CCSN properties is ... mass accretion onto the PNS!
*Too much accretion leads to
BH formation and/or failed explosion.
2 4 6 8 0.1 0.2 0.3 0.4 0.5 ξ2.5 neutrino luminosity [1052erg/s] time after bounce [s] 0.0 0.1 0.2 0.3 0.4 2 4 6 8 0.1 0.2 0.3 0.4 0.5 ξ2.5 neutrino luminosity [1052erg/s] time after bounce [s] 0.0 0.1 0.2 0.3 0.4
ü Showing 101 models with solar metallicity. The other models with lower metallicity have a similar trend (not shown here). ü The difference of Lν is more than double. 2-6 1052 erg/s @ t = 200 ms. smoothed over Δt = 20 ms. Compactness parameter O’Connor & Ott 2011 ξM ≡ M/M⊙ R(M)/1000km.
2 4 6 8 0.1 0.2 0.3 0.4 0.5 ZAMS mass [M⊙] neutrino luminosity [1052erg/s] time after bounce [s] 10.0 20.0 30.0 40.0 2 4 6 8 0.1 0.2 0.3 0.4 0.5 ZAMS mass [M⊙] neutrino luminosity [1052erg/s] time after bounce [s] 10.0 20.0 30.0 40.0
ü The compactness-colored lines show a monotonic trend.
3.0 3.5 4.0 4.5 10 15 20 25 30 35 40 e-neutrino lumi. [1052erg/s] ZAMS mass [M⊙] 1.2 1.4 1.6 1.8 2.0 2.2 10 15 20 25 30 35 40 remnant mass [M⊙] ZAMS mass [M⊙] 0.2 0.4 0.6 0.8 10 15 20 25 30 35 40 explosion energy [1051erg] ZAMS mass [M⊙] 2.0 4.0 6.0 10 15 20 25 30 35 40 nickel mass [10-2M⊙] ZAMS mass [M⊙] 3.0 3.5 4.0 4.5 0.0 0.2 0.4 0.6 0.8 e-neutrino lumi. [1052erg/s] compactness parameter ξ2.0 0.2 0.4 0.6 0.8 0.0 0.2 0.4 0.6 0.8 explosion energy [1051erg] compactness parameter ξ2.0 2.0 4.0 6.0 0.0 0.2 0.4 0.6 0.8 nickel mass [10-2M⊙] compactness parameter ξ2.0 1.2 1.4 1.6 1.8 2.0 2.2 0.0 0.2 0.4 0.6 0.8 remnant mass [M⊙] compactness parameter ξ2.0
0.1 0.2 0.3 M . [Mo
. s-1]
3.0 4.0 5.0 Lνe [1052 erg s-1]
200 400 600 800 0.0 0.1 0.2 0.3 0.4 t400 [ms] compactness parameter ξ2.5
0.4 0.8 1.2 1.6 E .
1.5 2.0 2.5 MPNS [Mo
.]
0.0 0.1 0.2 0.3 0.4 1.0 2.0 3.0 4.0 MNi [10-2 Mo
.]
Strong shock heating produces ejecta rich in nickel.
⑥
Compact progenitor suffers from high mass accretion rate,
①
so that it takes longer time to revive a stalled shock
②
.. and leaves a massive remnants at the center.
③
Accreted matter releases grav. energy which is carried away by neutrinos.
④
High neutrino luminosity results in an energetic explosion.
⑤
@t=t400 @t=tfin. KN+’15, PASJ
"Delayed coincidence"
ü Water-Cherenkov detector
ü Reaction channels
Gd-loaded SK can drastically suppress the background noise (Beacom & Vagins '04).
ü Water-Cherenkov detector
ü Reaction channels
Number of targets
ü Observed event rate:
2 4 6 8 0.1 0.2 0.3 0.4 0.5 ZAMS mass [M⊙] neutrino luminosity [1052erg/s] time after bounce [s] 10.0 20.0 30.0 40.0
ü Water-Cherenkov detector
ü Reaction channels
Number of targets
ü Observed event rate: ü Timing information (via IBD): the bounce time within 3.0 ms (HK) at 95% confidence level. ü Pointing information (via e- scattering): ~ 6˚ (SK), ~ 3˚ (SK-Gd), ~ 2˚ (HK) ~ 0.6 (HK-Gd)
KN+’16, MNRAS
s17.0
0.1 1 10 100
5 10 15 20 25 30 FOV diameter (deg) Optical magnitude 5 10 15 Probability (%)
9.8% 15.6% 15.5% 13.5% 11.5% 9.4% 7.4% 16.1% 1.2%
LSST Subaru Blanco CFHT ZTF Pan-STARRS Evryscope ASAS-SN
SK SK-Gd 1-2m 4m >8m
Naked eye
dark→ ←bright
KN+’16, MNRAS
Red Supergiant (RSG) progenitor → Type II SN Wolf-Rayet (WR) progenitor → Type Ib/c SN SBO (pre-SN neutrino) neutrino burst R* ~ 1011 cm → Δt ~ R*/v ~ 100 s (a few minutes) ! R* ~ 1013-14 cm, shock velocity ~ 109 cm/s → Δt ~ R*/v ~ 104-5 s (a few hours - a day) Distribute ALERT ! (SN Early Warning System; SNEWS)
Smith+’11, MNRAS
2 4 6 8 0.1 0.2 0.3 0.4 0.5 ξ2.5 neutrino luminosity [1052erg/s] time after bounce [s] 0.0 0.1 0.2 0.3 0.4
0.001 0.01 0.1 1 10
Post-bounce time [s]
20 40 60 80 100 120 140
Events @ HK [per 1ms bin]
Electron scattering Inverse-beta decay
10 20 30 40
tpb [ms]
10 20 30 40
Events per 2ms
8.5 kpc
Template of neutrino light curves from numerical simulations Expected detection events
KN+’16, MNRAS
ü Observed event rate depends on the distance to SN.
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 2 4 6 8
N200-250ms/N0-50ms
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
Compactness
2 4 6 8
N200-250ms/N0-50ms
0.0 0.2 0.4 0.6 0.8 1.0 2 4 6 8 10 12
t @sD NΝ @eventsê1 ms binsD
@SK,$PRELIMINARY$ @SK$ @HK$ ξ2.5$$0.005$$$$$$$$$$$$$$$$$$$$$$$$$$$0.42$$ 101$models$
Horiuchi, KN+’17, J. Phys. G The ratio can be a distance- independent indicator.
2 3 4 5 6 0.2 0.4 0.6 0.8 1 Nutrino luminosity [1052erg/s] time after bounce [s] Ω0=0.0 1.1 1.2 1.3 1.4 1.5 2.0 2.5
4 6 8 10 12 14 16 18 0.2 0.4 0.6 0.8 1 Anti-Neutrino average energy [MeV] time after bounce [s] Ω0=0.0 1.1 1.2 1.3 1.4 1.5 2.0 2.5
ü Core rotation affects SN neutrino properties. 2D simulations for s20.0 progenitor with initial Ω0 = 0.0 - 2.5 rad/s. Lnueb <Enueb>
400 600 800 1000 1200 100 200 300 400 500 600 700 800 Neutrino event rate [1/100ms] time after bounce [ms] Ω0=0.0 1.1 1.2 1.3 1.4 1.5 2.0 2.5
ü Systematic study of CCSN properties (neutrino, explosion energy, etc.):
(10.8 - 75 Msun, ~400 models) are demonstrated.
ü Neutrinos from a Galactic CCSN:
ü Possible uncertainties in pinning down the compactness: