Y. Matsuo A), M. Hashimoto A), M. Ono A), S. Nagataki B), K. Kotake C), S. Yamada D) , K. Yamashita E)

Long Time Evolutionary Simulations in Supernova until SNR phase Included the Uncertainties of CSMs

A :Kyushu university 　 B : RIKEN 　 C : Fukuoka university 　 D : Waseda university 　 E : Yamanashi university

MMCOCOS December 2 – 6 , 2013

Cassiopeia A (Cas A)

Hwang et al. 2004

• Distance ： 3.4 kpc ( Reed et al. 1995)• Age ： ~330 yr ( Fesen 2006)• Forward shock --- 2.5 ±0.2 pc• Reverse shock --- 1.6 ±0.2 pc (Gothelf

2001)

• Progenitor: 20 ～ 35 M (Chevalier & Oishi 2003; Yong et al. 2006; Fesen & Becker 1991)

• Type IIb supernova ( krause et al. 2008 )• The progenitor has less H-

envelop• There is the emission line of Fe.

• It is likey that Fe exists outside Si in Cas A (Vink et al. 2004, Badenes 2010) .

This indicates the mixing between Si- and Fe-rich matters during the expansion. Badences 2010

• From the observations, …• There is the emission line of Fe in Cas A.• It is likely that Fe exist outside the Si.

• Nobody have simulated the evolution of the elements from the onset of SN explosion to SNR phase.

• So we try to simulate the SN shock expansion and trace the elements (in particular H,He,O,Si,Fe) from the onset of the explosion to SNR phase (330 yr).

• In this study, we investigate whether Fe collides with the reverse shock at which the fluid instability develops.

Motivation

• Progenitors• 6 M He core model (Hashimoto 1995) and 3.8 M CO core model

• Circumstellar mediums (CSMs)• We assumed that CSM consists of RSG wind and/or WR wind.• We adopted the several wind parameters ( for details, please see

my poster)

Initial models

Density profiles of the progenitor modelsDensity profiles of the CSM models

Results

• In the case of 6M He core models, Fe does not collide with the reverse shock in most CSM models.

• In the case of 3.8M CO core models, Fe collides with the reverse shock in slow wind models.

6.0M He core and slow wind (TWR = 4000 yr)

3.8M CO core and slow wind (TWR = 4000 yr)

Fe would be mixed because the fluid instability develops around the reverse shock region.

Red: H, green:He, blue:O, pink:Si, aqua:Fe

The position of shocks and Fe

RSG wind model

RFS (pc)

RRS (pc)

Slow RSG wind 2.2 1.5Middle RSG

wind2.6 1.9

Fast RSG wind 3.0 2.2

WR wind model RFS (pc)

RRS (pc)

Slow wind model (TWR=4000yr)

2.3 1.3

Slow wind model (TWR=8000yr)

2.4 1.2

Slow wind model (TWR=16000yr)

2.5 1.6

Middle wind model (TWR=2000yr)

2.7 1.8

Middle wind model (TWR=4000yr)

2.8 1.6

Middle wind model (TWR=8000yr)

2.7 1.8

Fast wind model (TWR=1000yr)

3.1 2.2

Fast wind model (TWR=2000yr)

3.2 2.0

Fast wind model (TWR=4000yr)

3.1 2.2

Fe ～ 1.2 pc

2D results of the slow wind modelSlow wind model ( TWR = 8000 yr)

RTI develops around the O-rich region.But Fe –rich matter are not mixed because … 1) the mixing time of Fe are not enough to mix 2) Fe are not mixed in the star before the shock pass through the stellar surface.

The expansion velocity of Fe is too slow.

• From the observations, Fe reaches at the reverse shock ( r = 1.6 pc )

• 1.6 pc / 330 yr = 4740 km/s ~ 5000 km/s• So, we need that the Fe-velocity is about 5000 km/s at

least.• Now, VFe in our models is 3000-3500 km/s at most.• We need to increase the expansion velocity of Fe

by a factor of ~ 1.5 at least.

• Fe need to be mixed up to the O-rich layers when the shock pass through the stellar surface.

How do we need the expansion velocity of Fe ?

Fluid element velocity (slow RSG wind)

• The ejecta expand at constant velocity after the ejecta reach the stellar surface.• Expansion velocities of …

• O ~ 4000 – 6000 km/s• Si ~ 3500 – 4000 km/s• Fe ~ 3000 – 3500 km/s

Red: H, green:He, blue:O, pink:Si, aqua:Fe

• From the observation, Fe reach at the reverse shock ( r = 1.6 pc )

• 1.6 pc / 330 yr = 4740 km/s ~ 5000 km/s• So, we need that the Fe-velocity is about 5000 km/s

• Now, VFe in our models is 3000-3500 km/s.• We need to increase the expansion velocity of Fe

by a factor of ~ 1.5 at least.

• Fe need to be mixed up to the O-rich layers when the shock pass through the stellar surface.

How do we need the expansion velocity of Fe ?

• We try to simulate the formation of SNR from onset of SN explosion and compare the results and the observation of Cas A.

• From the observation, Fe reaches at reverse shock and it is likely that Fe and SI mixed during the explosion.

• In all our models, Si and Fe are not mixed because the mixing between SI and Fe at SN explosion are not enough that Fe collides with the reverse shock.

• We find that expansion velocity of Fe need to be increased by a factor of ~ 1.5 at least and this problem is not solved if CSM distribution are changed.

• We should the estimate of growth rate of RTI to investigate the reason why Fe are not mixed in the star.

• So, we will try to mix Fe to O-shell artificially and investigate the possibilities that Fe would exist outside the Si.

Summary