1/12 E. T. Li 14th, Sep. 2018

The 26Al yields in single stars

Ertao Li

Shenzhen University, Shenzhen, China

Konkoly Observatory, Budapest, Hungary

14th Sep. 2018

2/12 E. T. Li 14th, Sep. 2018

RADIOSTAR: (PI Maria Lugaro)

For more info you can find here:

http://konkoly.hu/radiostar/index.html

3/12 E. T. Li 14th, Sep. 2018

Outline

• Motivations;

• 26Al yields in single stars;

• The influence of 26Al isomeric state;

• Conclusions.

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26Al in meteorites & the Galaxy

• A direct proof of the ongoing nucleosynthesis in our galaxy

• The total amount of live 26Al is 2.0 (± 0.3) solar mass

• The source of 26Al favor massive star R. Diehl et al., Nature 439(2006)45. A&A 298(1995)445.

Leoville carbonaceous meteorite

W. Stegmann et al., EPSL 55(1981)266. P. Hoppe et al., APJ430(1994)266.

Murchison Silicon carbide grains

MPE Garching/Roland Diehl

• Give more information about the birth of

the Solar System.

• The decay of 26Al in the ESS could

have important consequences to our

earth.

M. Lugaro, et al., 2018 PPNP 102, 1.

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Possible 26Al sources

• Hydrostatic H-burning

• Explosive H-burning

• Hydrostatic Ne/C-burning

• Explosive Ne/C-burning

• Spallation of cosmic rays

• Single stars

• Binary stars

R. Diehl et al., 1995 A&A 298, 445.

N. Prantzos et al., 1996, PR, 267, 1

R. Diehl et al., 1998, PASP, 110, 637

C. Iliadis et al., 2011 APJ 193, 16.

M. Lugaro, et al., 2018 PPNP 102, 1.

............

The 26Al sources are still debating……

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26Al yields in single stars

• The one-dimensional open source code: MESA is used to do the calculations

http://mesa.sourceforge.net/ (64 isotopes + 557 reactions, Z = 0.014)

M. Limongi et al., 2006, APJ 647,483

( )

( ) ( )

• The more initial stellar mass the

more 26Al production in stars.

• Above 30M⊙: the yields in winds

agree with Limogi’s, even if the

metallicities are different (Limogi’s:

Z = 0:02)

• At 10M⊙ & 20M⊙: the yields are

bigger than Limogi’s.

• At 5M⊙: the yields enhanced a lot?

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5M⊙ & 10M⊙ Kippenhann diagram

5M⊙ 10M⊙ • The 26Al in the outer

convection mixing is

bigger at 5M⊙;

• Dredge up appear at 5M⊙,

no dredge up at 10M⊙;

• The dredge up mixing

increase the yields in

winds.

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Reaction flux to determine the important reactions

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Reaction flux at 30M⊙

25Mg(p,γ)26Alg 25Mg(p,γ)26Alis 26Alg(n,α)23Na

Mg—Al cycle

22Ne(α, n)25Mg 25Mg(n, γ)26Mg 22Ne(α, γ)26Mg 24Na decay 23Na(α, p)27Mg

• The reaction sensitivity to the yields of 26Al are still going on.

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The influence of 26Al isomeric state

S. S. Gupta et al., Phys. Rev. C 64(2001)025805.

4 states

R. Rene et al., Int. J Mod. Phys. A 33(2018)9.

11 states

Weisskopf approximation

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The influence of 26Al isomeric state

5M⊙

Rene et al.

Gupta et al.

4%

50M⊙

Rene et al.

Gupta et al.

60%

• The new γ - decay rates between the ground and isomeric states of 26Al

increase the 26Al yields (in wind), 4% at 5M⊙ and 60% at 50M⊙.

• The effects at other stellar masses are still calculating.

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Conclusions

• The 26Al sources are still debating;

• In single stars, the more stellar mass the more 26Al production;

• The 26Al yields in winds agree with other works at above 30M⊙;

at 10M⊙ and 20M⊙ our results are higher;

• The dredge up mixing at 5M ⊙ enhance 26Al yields in winds;

• For the future sensitivity test he reaction flux is used to decide

which reaction is more important;

• The new γ - decay rates between the 26Al ground and isomeric

states increase the 26Al yields.

13/12 E. T. Li 14th, Sep. 2018

谢谢

Köszönöm

Thank you for your attention