Supernovae and Nucleosynthesis

Shigehiro Nagataki

21-27 August 2014, RIKEN, JAPAN The 13th CNS International Summer School (CNSSS14)

1st Lecture on 22nd Aug.

Massive Stars Explode.

たいよう

A Supernova that may happen tomorrow ～Betelgeuse～

If Betelgeuse will explode as a supernova,…

Estimated by Nomoto’s Group (IPMU).

3 hours later

It can be seen by naked eyes at a daytime even three months later.

Orion will lose Betelgeuse four years later.

1000yrs later：Supernova Remnant

It contains lots of heavy elements. Origin of Life.

Human beings experienced such a great sky-show in the past!

Supernova Remnant 1006 (A.D.1006)

A record on SN1006 in Meigetsu-Ki by T. Fujiwara.

フラックス

Blue：X-ray Red: Radio

No Supernova, No Life.

Carbon Iron Magnesium

Cupper Silver Gold

F

A stellar Structure. From NASA HP

Heavy Elements are produced In Massive Stars

From NASA HP

Birth of Earth & Moon

From NASA HP & BBC

Summary of Introduction

• Massive Stars Explode as Supernovae.

• Nucleosynthesis in Massive Stars & Supernovae.

• No Supernova, No Life.

Massive Stars Explode. Why?

Simulation by T. Takiwaki (RIKEN)

The Mystery Lasting Over 80 Years

Neutrino Heating

１９３４

Outline of Explosion Mechanism

core collapse

H

He C+O

Si

Fe

ν ν

ν

ν

ν trapping core bounce

ν

ν ν

ν

ν

ν ν

ν

NS

shock propagation in core shock in envelope SN explosion

From S. Yamada

Key Process I: EOS and Shock Formation Entropy:T^3/ρ It’s a good measure for the shock. At the shock, kinetic energy is converted to heat and temperature increases(i.e. entropy also increases.)

Nuclear Physics for the Dynamics ～Equation of State in Dense Matter～

From F. Weber 2005

Theoretical Nuclear Physics Groups in RIKEN

Dr. T. Hatsuda

Dr. E. Hiyama

A New Table for EOS for Dense Matter can be Provided.

Dr. T. Nakatsukasa

Key Process II: Neutrino Mechanism Shock

Radius

Radial Velocity

Pressure

Ram Pressure (RHS) is determined by stellar structure(density profile).

Ram Pressure

The shock stalls. Pressure behind it and ram pressure from outside balances.

Entropy~T^3/ρ

Proto Neutron Star

Fe=>n, p Pressure (LHS) is determined by two effects. (1) Photo-dissociation (2) Neutrino Heating

Cooled by Photo-dissociation

Heated by neutrino

Postshocked n,p

Preshocked Fe

Post Shock

Balance between Cooling and Heating From T. Janka 01

～ Const

～

i.e.

Also.

So, Cooling Dominates at small r, while Heating Dominates at large r.

An Example of a Failed Supernova…

T. Takiwaki (RIKEN)

EoS： LS-K220 resolution： 384(r)x1(θ)x1(φ) The finest grid Neutrino Trasport： Ray-by-Ray:IDSA +Leakage Hydro: HLLE, 2nd order

K-Computer in RIKEN & Post-K-Computer Project

K-Computer’s Speed is 10 Peta Flops (Fastest in the World in Jun. –Nov. 2011. Now 4th ranked). The Post-K-Project （Exa-Flops, 2020-） has already started in RIKEN.

京(KEI) = 10 Peta=10^16.

Supernova as a Source of Neutrinos and GWs

Neutrinos

Gravitational Waves

SN1987A

Super-Kamiokande （Kamioka, Japan）

KAGRA (2017-) （Kamioka, Japan）

Prof. M. Koshiba, Awarded the Nobel Prize in Physics (2002).

Neutrino/GW Signals from a SN

Time Evolution of Neutrino Luminosity

Signal of Gravitational Wave in Freq. Space

T. Takiwaki (RIKEN).

Effects of Rotation

Spiral wave transfer the energy to the outer regon. Finally explosion is found! T. Takiwaki

(RIKEN).

Related with Asymmetry of Ejecta？

Strong Explosion is Found on Equatorial Plane.

The mass of the progenitor and rotation make various type of Explosion(or Non Explosion).

Observation of SN1987A: Asymmetric Explosion!

Futher Mystery: Gamma-Ray Bursts

Our Road Map • 2017: K-Computer Up-Graded (～100PFlops). • 2017: KAGRA Full Operation (GW). • 2020: Post K-Computer Full Operation (Exa-Flops). • 2020: 6D Supernova Simulation Done. • 2025: 6D Gamma-Ray Burst Simulation Done. • 203X: A SN Explodes in Milky Way (Betelgeuse?). Neutrinos & GWs Detected. Our Theory Confirmed. EOS for Dense Matter Determined. • 204X: Lots of Nobel Prize Winners from Japan. • … Our Dreams Will Continue…

Researches on Explosion Mechanism of CC-SN in the World

3D self-consistent simulation by Florian Hanke (Max Planck Institute for Astrophysics)

Summary • Massive Stars Explode. Why? This is a Mystery

Lasting over 80 years. • Key Process I : Equation of State for Dense Matter. • Key Process II : Neutrino Heating • 3-Dimension for Space & Momentum-Space is

Crucial: Super-Computing. • No Supernova, No Life. • Further Mystery: Gamma-Ray Bursts.

Back Up

Summary: Why are Supernova Simulation Difficult? • Energy Source is Gravitational Binding

Energy：～10＾53 erg. • 99% of the energy is lost in the form of Neutrinos. • Through weak interactions, 1% of neutrino’s energy is transferred to Matter Explosion Energy：～10^51 erg. • The Spectrum of Neutrinos are not thermal. • Convections and some hydro-instabilities are also

important for heating efficiency. • So, 6D simulations with lots of physics (EOS, Neutrinos,

Gravity, MHD…) are necessary for complete understanding. • Simulation by K（3D in Space, 1D in Neutrino）：Exploded！ • Simulation by Post-K（6D）：For Complete Understanding！

Gravity PNS ～10km

Neutrinos

Iron Core ～1000km