2023/02/27
Interacting Supernovae@MIAPbP, München

CHIPS: an open-source code formodelling supernovae interacting witha massive circumstellar medium
Yuki Takei and Team CHIPS: Daichi Tsuna, Naoto Kuriyama,
Takatoshi Ko, and Toshikazu Shigeyama
doi: 10.3847/1538-4357/ac60fe

https://github.com/DTsuna/CHIPS

What powers the supernova?
Ejecta powered

Central engine powered

Interaction powered
CSM

SNejecta

SNejecta

SNejecta

NS/BH

NS/BH

NS/BH

Internal energy/Ni56
inside SN ejecta(Type IIP/IIL, Type I)

Energy injection to ejecta
from inside. Powered bycentral compact object(Type I SLSN?)

Collision of ejecta &“wall”. Powered byejecta’s kinetic energy(SN IIn, Type II SLSN)How to make dense CSM?
Standard “stellar wind” seen inmassive stars: ≾ 10−4 𝑀⊙ /yr
Too low to explain Type IIn(LBV-like) mass eruption just before
core-collapse?

https://en.wikipedia.org/wiki/Eta_Carinae

Type IIn

Mass eruption modeling• Kuriyama & Shigeyama 2020
• Inject energy at the base of thestellar envelope (~few 10 % ofenvelope’s binding energy)• Assume that the injected energy
source is the nuclear burning.

Mass eruption modeling

Shock propagation in stellar envelope

Light curve of precursor

Why IIn LC modelling?
• Most of previous studies focus on SNe IIn interacting with dense CSM whose density
profile is proportional to 𝑟 −2 (steady wind) or single power-law profile (e.g. Moriya+11,
Chevalier & Irwin 11, Chatzopoulos+12, Ginzburg & Balberg 12, Moriya+13, Tsuna+19,
Takei & Shigeyama 20, Suzuki+20…)• CSM density structure affects the light curve (right figure)• More realistic modeling of CSM leads to better understanding of SNe IIn.

𝜌 ∝ 𝑟 −2 model𝜌 ∝ 𝑟 −1.5 model𝜌 ∝ 𝑟 −1.5

Tsuna, YT,+21

CHIPS Project

YT, Tsuna, Kuriyama, Ko, Shigeyama
https://github.com/DTsuna/CHIPS

Open-source code aimed to unveil theComplete History of Interaction-Powered Supernovae

Parameters (user option)• 𝑀 (𝑀⊙ ): Initial mass (we have sample models of 13, 14, …,26 solar masses)• 𝑓inj : Energy injected at the base of the stellar envelope,
scaled with the envelope’s binding energy (order of 0.1-1)• 𝑡inj (yr): Time from energy injection to core-collapse• 𝐸ej (ergs): Explosion energy of supernova

Parameters (user option)

Inject𝑓𝑖𝑛𝑗 = −𝐸𝑖𝑛𝑗 𝐸𝑏𝑖𝑛𝑑Explosion energy of 𝐸𝑒𝑗

After 𝑡𝑖𝑛𝑗 (yr)CSM mass

15𝑀⊙
model𝜌 ∝ 𝑟 −1.5

Dependence on 𝒕inj

Dependence on 𝒇inj
FBOTs

RETs

IIn

CHIPS can also reproduce the features of other interaction-powered transients such as:• Rapidly evolving transients (e.g., Drout+14, Arcavi+16, Pursiainen+18)• Fast blue optical transients (e.g., Prentice+18, Ho+20, Perley+21)

Dependence on 𝑬ej

RETsIInComparison with observation: SN 1998S• 𝑡rise ~20 days, 𝐿peak ~2 × 1043 erg/s• Corresponding parameter space: 𝐸ej ∼ 1051 erg, 𝑡inj ∼ 10 yrs, 𝑓inj ∼ 0.8
SN 1998S

Elias-Rosa+18

Comparison with observation: SN 1998S• 𝑓𝑖𝑛𝑗 = 0.7, 𝑡𝑖𝑛𝑗 = 11 yr, 𝐸𝑒𝑗 = 2.5 × 1051 erg, 𝑀∗ = 20𝑀⊙
• Well reproduce each light curve (BVR, bolometric)• Tail: radioactive decay of 56Co with mass of 0.15Msun• Large explosion energy → large nickel mass (Hamuy 2003)

Summary• Previous works focus on simple CSM density profile of 𝜌 ∝ 𝑟 −𝑠
• Some massive stars are known to experience mass eruption(s), which forms
dense CSM.
• CHIPS code simulates both the creation of CSM from mass eruption andsubsequent SN light curve (https://github.com/DTsuna/CHIPS).
• We can reproduce LC features of interaction-powered transients by CHIPS.

Future work
• Spectral modeling (Ishii, YT+, in prep.)• Expand CHIPS code to Ibn modeling (YT+, work in progress)