Evolutions of stars just below the critical mass for iron core - - PowerPoint PPT Presentation

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Evolutions of stars just below the critical mass for iron core - - PowerPoint PPT Presentation

Dec 06, 2022 123 likes •316 views

Evolutions of stars just below the critical mass for iron core formation Koh Takahashi, Hideyuki Umeda, & Takashi Yoshida Department of Astronomy, University of Tokyo 9-11Mo Introduction 9-11Mo stars evolution

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SLIDE 1

Evolutions of stars just below the critical mass for iron core formation

Koh Takahashi, Hideyuki Umeda, & Takashi Yoshida

Department of Astronomy, University of Tokyo

9-11Moの恒星のコア進化

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SLIDE 2

Introduction

9-11Mo stars evolution ・Fe core formation → CCSNe Mcrit =??

・complex features

・Thermal Pulse (SAGB) ・ONeMg core ?? → ECSNe

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SLIDE 3

Introduction

9-11Mo stars evolution ・calculate with large nuclear reaction network

(282 species of nuclei : from n, H to Br)

and with fine initial mass grid

(ΔM = 0.01Mo)

1 1 79

・Poelarends et al. (2008) ・Nomoto & Hashimoto (1988)

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SLIDE 4

center T-rho diagram

Fe core O+Ne+Mg core

→・ONeMg WDs? ・ECSNe ? → CCSNe

Mcrit ?

TH ~10^7 yr TC ~10^4 yr THe ~10^6 yr He H C Ne+O+Si

7 7.5 8 8.5 9 9.5 10 2 4 6 8 10 log Tc [K] log !c [g/cc] M=9 Mo M=10 Mo

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SLIDE 5

7 7.5 8 8.5 9 9.5 10 2 4 6 8 10 log Tc [K] log !c [g/cc] M=9 Mo M=10 Mo

Mcrit ?

center T-rho diagram

Fe core O+Ne+Mg core

→・ONeMg WDs? ・ECSNe ? → CCSNe TH ~10^7 yr TC ~10^4 yr THe ~10^6 yr He H C Ne+O+Si

1e-05 0.0001 0.001 0.01 0.1 1 0.5 1 1.5 2 mass fraction mass[M/Mo] H He C O Ne Mg Si Fe

9Mo(beginning of TP) : ONeMg core

O Ne Mg He H

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SLIDE 6

7 7.5 8 8.5 9 9.5 10 2 4 6 8 10 log Tc [K] log !c [g/cc] M=9 Mo M=10 Mo

Mcrit ?

center T-rho diagram

Fe core O+Ne+Mg core

→・ONeMg WDs? ・ECSNe ? → CCSNe TH ~10^7 yr TC ~10^4 yr THe ~10^6 yr He H C Ne+O+Si

10Mo(before Core Collapse) : Fe core

1e-05 0.0001 0.001 0.01 0.1 1 0.5 1 1.5 2 mass fraction mass[M/Mo] H He C O Ne Mg Si Fe

Fe Si O He

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SLIDE 7

7 7.5 8 8.5 9 9.5 10 2 4 6 8 10 log Tc [K] log !c [g/cc] M=9 Mo M=10 Mo

center T-rho diagram

Fe core O+Ne+Mg core

→・ONeMg WDs? ・ECSNe ? → CCSNe TH ~10^7 yr TC ~10^4 yr THe ~10^6 yr He H C Ne+O+Si

degenerate core

Mcrit ?

・for Fe core formation, Mcrit = ? ・degenerate core evolution

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SLIDE 8

Results

7 7.5 8 8.5 9 9.5 10 2 4 6 8 10 log Tc [K] log !c [g/cc] M/Mo=9 9.5 9.7 9.8 9.78 9.79 9.9 9.81 10 11

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SLIDE 9

8.4 8.6 8.8 9 9.2 9.4 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 log Tc [K] log !c [g/cc] M/Mo=9 9.5 9.7 9.8 9.78 9.79 9.9 9.81 10 11

Results

Mcrit ~ 1.37 Mo(9.7 Mo) for Ne burning 1.71 1.27 1.49 1.40 1.40 1.38 1.370 1.369 1.33 1.29 1.373 Mcrit ~ 1.38 Mo(9.8 Mo) for Si burning

for Fe core formation, MCOcore > 1.38 Mo

・1.71 etc. : CO core mass [Mo] ・ : measure point (at the end of C burning)

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SLIDE 10

8.4 8.6 8.8 9 9.2 9.4 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 log Tc [K] log !c [g/cc] M/Mo=9 9.5 9.7 9.8 9.78 9.79 9.9 9.81 10 11

some features

②Ne+O+Si pulse

for 9.9Mo

① property change

for 9.8Mo

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SLIDE 11

8.4 8.6 8.8 9 9.2 9.4 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 log Tc [K] log !c [g/cc] M/Mo=9 9.5 9.7 9.8 9.78 9.79 9.9 9.81 10 11

some features

②Ne+O+Si pulse

for 9.9Mo

① property change

for 9.8Mo

9.8Mo : beginning of Ne burning

Si O Ne Mg

1e-05 0.0001 0.001 0.01 0.1 1 0.5 1 1.5 2 mass fraction mass[M/Mo] H He C O Ne Mg Si Fe

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SLIDE 12

8.4 8.6 8.8 9 9.2 9.4 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 log Tc [K] log !c [g/cc] M/Mo=9 9.5 9.7 9.8 9.78 9.79 9.9 9.81 10 11

some features

②Ne+O+Si pulse

for 9.9Mo

① property change

for 9.8Mo

9.8Mo : Ne burning termination

Si O Ne Mg

1e-05 0.0001 0.001 0.01 0.1 1 0.5 1 1.5 2 mass fraction mass[M/Mo] H He C O Ne Mg Si Fe

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SLIDE 13

・electron capture

  • n O products

MCh = 1.46(2Ye)^2 Mo

0.4 0.5 0.6 0.7 0.8 0.9 0.5 1 1.5 2 elec mole fraction mass[M/Mo]

① electron capture for 9.8Mo Ye ~ 0.48

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SLIDE 14

8.4 8.6 8.8 9 9.2 9.4 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 log Tc [K] log !c [g/cc] M/Mo=9 9.5 9.7 9.8 9.78 9.79 9.9 9.81 10 11

some features

②Ne+O+Si pulse

for 9.9Mo

① property change

for 9.8Mo

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SLIDE 15

8.4 8.6 8.8 9 9.2 9.4 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 log Tc [K] log !c [g/cc] M/Mo=9 9.5 9.7 9.8 9.78 9.79 9.9 9.81 10 11

some features

②Ne+O+Si pulse

for 9.9Mo

① property change

for 9.8Mo

9.9Mo : Ne+O+Si burning → Fe shell

Si O Ne Mg

1e-05 0.0001 0.001 0.01 0.1 1 0.5 1 1.5 2 mass fraction mass [M/Mo] H He C O Ne Mg Si Fe

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SLIDE 16

8.4 8.6 8.8 9 9.2 9.4 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 log Tc [K] log !c [g/cc] M/Mo=9 9.5 9.7 9.8 9.78 9.79 9.9 9.81 10 11

some features

②Ne+O+Si pulse

for 9.9Mo

① property change

for 9.8Mo

9.9Mo : Ne+O+Si burning → Fe shell

1e-05 0.0001 0.001 0.01 0.1 1 0.5 1 1.5 2 mass fraction mass[M/Mo] H He C O Ne Mg Si Fe

Fe Si O Ne Mg

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SLIDE 17

8.4 8.6 8.8 9 9.2 9.4 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 log Tc [K] log !c [g/cc] M/Mo=9 9.5 9.7 9.8 9.78 9.79 9.9 9.81 10 11

some features

②Ne+O+Si pulse

for 9.9Mo

① property change

for 9.8Mo

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SLIDE 18

Summary

・We have calculated the evolution for 9-11Mo stars with large nuclear reaction network. ・The critical mass for Ne ignition is 1.37Mo for CO core, 9.7Mo for ZAMS. ・The critical mass for Si ignition is 1.38Mo for CO core, 9.8Mo for ZAMS. ご清聴ありがとうございました ・In an electron degenerate core, effects of neutrino cooling and elec. capture are important.