Development for New SNII Feedback Treatment

清水 一紘 (大阪大学)

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Table of Contents
Supernova feedback
Traditional modelOur new SNII (SNIa) feedback modelResults
Summary

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Traditional SNII model

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Traditional SNII scheme
stargasi. Kick velocity (vkick) assignment to nearest particles← momentum or energy conservation← constant kick velocity of all kick particles
Effective SNII radius depends on the simulation resolution
Global value (not local value)

ii. Cooling and hydro-interaction turns off if the below conditions satisfies
or根拠？

iii. Cooling and hydro-interaction turns on again if below conditions satisfies
or4/19Beyond the traditional model Traditional model Wind velocity is proportional to virial velocity of host halo⇒ using global value (halo information) not local value Non physical motivated value of effective radius of SNII is not Non physical motivated value of no cooling and hydro-interaction time

In far future, each Star (not assumption IMFs) may be resolved.
Moreover, SNII bubble of each star particle may be resolved.
We need to develop beyond the traditional model for such future.
 New model Using physical motivated values for SN feedback
・ Effective SNII radius, wind velocity, no-cooling time
⇒ Analytic solution (Sedov-Taylor solution)⇒ Using local value not using halo information

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New SNII feedback treatment

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New SNII feedback treatment
Schematic picture

Based on master thesis of Todoroki 2014

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New SNII feedback treatment
Based on analytic solution of SN bubble evolution
1. Calculation shock radius (Rshock)(Estimation density and pressure around star particles
using gas particle around them)stargasChevalier 1974, Stinson et al.2006

2. Assignment SNII energy (kinetic, thermal) to gas particles in Rshock(fiducial model : EK=0.3, ET=0.7)

I assign gas and Metal mass by SNII in the same manner
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New SNII feedback treatment
3.Estimation Kick velocity (vshock) based on energy conservation

Analytic solution of shock velocity in Sedov-Taylor phase

Resolution of our simulation is not enough to resolve SN bubble.
This method does not satisfy energy conservation if all kick particles
have this analytic velocities.
4.Cooling turns off during Sedov-Taylor phase (adiabatic phase).
But, hydro-interaction always turns on.

Chevalier 1974, Stinson et al.2006 9/19

Simulation Results
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Test for Isolated disk galaxy

Simulation code: Gadget3-Osaka

radiative cooling (grackle package)/heating, Star formation,
time dependence feedback (early stellar feedback, SNII, SNIa),
Time dependence metal yield (SNII, SNIa, AGB: CELib package, Saitoh 2016),
DISPH method (Saitoh & Makino ‘13, Hopkins’13)
Isolated disk galaxy initial condition (AGORA project)
Initial Gas distribution

face-onedge-on
Kim et al. 201611/19Galaxy evolution of each model
ESFB+SNII+SNIa

No FBESFB only

SNII only

SNIa only

Const wind

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Galaxy evolution of each model
ESFB+SNII+SNIa

No FBESFB only

SNII only

SNIa only

Const wind

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Star formation history
ESFB+SNII+SNIa
No FBESFB only
SNII only
SNIa only
Const wind (SH03)

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Kennicutt–Schmidt Law (1Gyr)

ESFB+SNII+SNIa
No FBESFB only
SNII only
SNIa only
Const wind (SH03)

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Projected temperature map (1Gyr)
ESFB+SNII+SNIa

No FBESFB only

SNII only

SNIa only

Const wind

Hot bubble structure can be seen in our model!
This is the specific feature of our model

AGORA comparison project: Kim et al. 2016

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Projected stellar density (1Gyr)
ESFB+SNII+SNIa

No FBESFB only

SNII only

SNIa only

Const wind

The number of sub-clump is very small!
Smooth distribution of stars can be seen.

AGORA comparison project: Kim et al. 201617/19

ρ-T plane (1Gyr)
ESFB+SNII+SNIa

No FB

Cold (< 5000 K)
Warm (5000 K < T < 105 K)
Hot (> 105 K)

ESFB only

SNII only

SNIa only

Const wind

Hot gas due to SN feedback

SN feedback makes high-dense, high-temperature gas particles.

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Summary (Isolated galaxy)
We develop new SNII feedback treatment
 Physical motivated SNII bubble evolution (Analytic solution)
 Using physical motivated value⇒ shock radius, wind velocity, no-cooling time Using local values not global values (halo information)

 Strong suppression of fragmentation and star formation activity
 Gas heating in dense gas is dominant effect(Gas eject to outside of galaxy by wind is not so strong) Compact stellar structure Success to reproduce kennicutt-schmidt law
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