Multi-D Simulations of Pulsational
Pair-Instability Supernovae

Ke-Jung (Ken) Chen
Academia Sinica Institute of Astronomy and Astrophysics (ASIAA)
MIAPbP Workshop, 02/27/2023

The Explosion Group at ASIAA
Since Sep. 2018 ~The Explosion Group at ASIAA
Since Sep. 2018 ~Eruptive Mass Loss and SNe of Massive Stars(The story began when I was a PhD student at Minnesota)

Ofek, E. O., et al. Nature (2013)

3

The engine of eruptions

Fate of Very Massive Stars
Star > 80 M⊙

We have a better understanding ofThermonuclear explosion

Fate of Very Massive Stars
Star > 80 M⊙

We have a better understanding ofThermonuclear explosion

Fate of Very Massive Stars
Star > 80 M⊙

We have a better understanding ofThermonuclear explosion

𝞬

Fate of Very Massive Stars
Star > 80 M⊙< 4/3

We have a better understanding ofThermonuclear explosion

𝞬

Fate of Very Massive Stars
Star > 80 M⊙< 4/3

We have a better understanding ofThermonuclear explosion

𝞬

Fate of Very Massive Stars
Star > 80 M⊙< 4/3

We have a better understanding ofThermonuclear explosion

𝞬

Fate of Very Massive Stars
Star > 80 M⊙< 4/3

We have a better understanding ofThermonuclear explosion

Central oxygen
depletion
Based on Stan’s Model
Woosley+ 2007, Woosley+ 2017
Woosley Priv. Comm.

80 M⊙ Helium core 35.7 M⊙
Pulsational instability
begins shortly after central
oxygen depletion when thestar has about one day left
to live (t = 0 here is ironcore collapse).
Pulses occur on ahydrodynamic time scale
for the helium and heavy
element core (~500 s).
For this mass, there areno especially violent single
pulses before the starcollapses. Nevertheless,there may be mass ejection.

90 M⊙
Helium core 41.3 M⊙
2 daysPulses commence again
after central oxygen
depletion, but become
more violent. Two strong
pulses send shock waves
into the envelope.
Two days later theiron core collapses.

For still larger helium cores, thepulses become more violent andthe intervals between themlonger. Multiple supernovae
occur but usually just one ofthem is very bright.

Total ejected mass from 0.1 M⊙ to 8 M⊙ depending on thehelium core mass !!

Core of 110 M⊙ stars（cm/s）

9Core of 110 M⊙ stars（cm/s）

9

Core of 110 M⊙ stars（cm/s）

9Eruption History of a 110 M⊙ star
The star produces three violent outbursts.The rst, P1, ejects most of the hydrogenenvelope, making a faint Type II supernova and leaving a residual of 50.7 Msun, just a
bit more than the helium core itself. After 6.8 yr, the core again contracts andencounters the pair instability, twice in rapid succession. The total mass of the second
and third pulses (P2 and P3) is 5.1 Msun and their kinetic energy is 6e50 erg. P3
collides with P2 at large optical depths that are not visible to an external observer.
These combined shells then overtake P1 at 1e15 cm and speeds of a few 1000 km/s.

fi ˘Chen+ ApJ 792 28 (2014)

Physical Properties of Colliding Shells

Chen+ (2014)

Physical Properties of Colliding Shells

Chen+ (2014)

Physical Properties of Colliding Shells

Chen+ (2014)

1D Transport Simulations of PPSNeMultidimensional Radiation Transport Simulations of PPSNe
Chen+ (astro-ph1904.12873)

Multidimensional Radiation Transport Simulations of PPSNe
Chen+ (astro-ph1904.12873)

Multidimensional Radiation Transport Simulations of PPSNe
Chen+ (astro-ph1904.12873)

Multidimensional Radiation Transport Simulations of PPSNe
Chen+ (astro-ph1904.12873)

Light Curves

Summary of (P)PISNe(Courtesy of Stan)