Structure and Evolution of Massive Stars (and of the less massive ones also...) Ana Palacios, LUPM / Université de Montpellier

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1 Structure and Evolution of Massive Stars (and of the less massive ones also...) Ana Palacios, LUPM / Université de Montpellier

3 The Hertzsprung Russell diagram New reduction fo Hipparcos Catalog

4 The evolutionary path of stars Stars move from red to blue to red again The fate of low and intermediate mass stars and their evolutionary path are relatively well known and constrained. The evolutionary path and fate of massive stars is very uncertain Iben 1991

5 The evolution of massive stars Mass loss driven evolution Maeder et al., 2008, IAUS 250 normal evolution 60 M Groh et al. 2014

6 Standard structural evolution of a massive star Heger & Woosley

7 Standard structural evolution of a massive star Onion-skin structure of the core of an evolved massive star Kippenhahn & Weigert book new edition

8 Expected fate from standard stellar evolution models SNIIP, other SNII, SNIb/Ic Eldridge et al. 2013

9 Expected surface abundance variations in massive stars O: No variation expected BSG to RSG : 4 He H 14 N 12 C and 14 O C and N WC: WN : Ne and 16 O Mg 25 Meynet & Maeder, 2003, A&A 404, 975 N C and Ne 16 O

10 Standard structural evolution of an intermediate mass star (1) Evolution up to the e-agb Kippenhahn & Weigert book new edition

11 Expected surface abundance variations in IM stars 4 He 12C 13C 14N 3 He 7Li After the 2nd DUP, 4He and N appear 14 enhanced at the surface of the star 1.14 x 108

12 Expected surface abundance variations in IM stars H-burning (HBS+HBB) 14 N,13C,15N,23Na,25,26Mg, 26,27Al He-burning (HeBS+pulse) 12 C,16O,18O,19F,20Ne,22Ne,25,26Mg figure by M. Forestini

13 Standard structural evolution of an intermediate mass star (2) AGB and post-agb evolution Kippenhahn & Weigert book new edition

14 Expected fate of stars from standard stellar evolution models After Siess 2006

15 The drivers of evolution Nucleosynthesis through exothermic nuclear reactions Mass loss for massive or evolved stars See Talk by F. Martins

16 The drivers of evolution Nucleosynthesis through exothermic nuclear reactions Mass loss for massive or evolved stars See Talk by F. Martins What processes actually matter in shaping the structure and evolution of stars?

17 The drivers of evolution Nucleosynthesis through exothermic nuclear reactions Mass loss for massive or evolved stars See Talk by F. Martins What processes actually matter in shaping the structure and evolution of stars? Any process that will affect the internal chemical stratification and the surface opacities

18 The drivers of evolution Nucleosynthesis through exothermic nuclear reactions Mass loss for massive or evolved stars See Talk by F. Martins What processes actually matter in shaping the structure and evolution of stars? Any process that will affect the internal chemical stratification and the surface opacities It is the case of dynamical processes

19 The drivers of evolution Nucleosynthesis through exothermic nuclear reactions Mass loss for massive or evolved stars See Talk by F. Martins What processes actually matter in shaping the structure and evolution of stars? Any process that will affect the internal chemical stratification and the surface opacities It is the case of dynamical processes Rotation

20 The drivers of evolution Nucleosynthesis through exothermic nuclear reactions Mass loss for massive or evolved stars See Talk by F. Martins What processes actually matter in shaping the structure and evolution of stars? Any process that will affect the internal chemical stratification and the surface opacities It is the case of dynamical processes Rotation Waves

21 The drivers of evolution Nucleosynthesis through exothermic nuclear reactions Mass loss for massive or evolved stars See Talk by F. Martins What processes actually matter in shaping the structure and evolution of stars? Any process that will affect the internal chemical stratification and the surface opacities It is the case of dynamical processes Rotation Waves Magnetic fields

22 The drivers of evolution Nucleosynthesis through exothermic nuclear reactions Mass loss for massive or evolved stars See Talk by F. Martins What processes actually matter in shaping the structure and evolution of stars? Any process that will affect the internal chemical stratification and the surface opacities It is the case of dynamical processes Rotation Waves Magnetic fields Turbulent instabilities

23 Successes and caveats of present-day models of low and intermediate-mass stars Modern models including rotation and other non-standard transport processes have improved the comparison with observations in terms of surface abundances Charbonnel & Lagarde 2010.

24 Successes and caveats of present-day models of low and intermediate-mass stars Modern models including rotation and other non-standard transport processes have improved the comparison with observations in terms of surface abundances Palacios et al Vini = 110 km/s Charbonnel & Lagarde Vini = 110 km/s

25 Successes and caveats of present-day models of low and intermediate-mass stars Modern models including rotation and other non-standard transport processes have improved the comparison with observations in terms of surface abundances Palacios et al Michaud et al Vini = 110 km/s Charbonnel & Lagarde Vini = 110 km/s

26 Successes and caveats of present-day models of low and intermediate-mass stars Modern models including rotation and other non-standard transport processes give hints for improvement on the side of angular momentum evolution vzams = 50 km/s Ω/2π (μhz) vzams = 20 km/s Garcia et al., 2011 Internal solar rotation profile inversion using 4608 days of MDI and GOLF data. Eggenberger et al., 2005 Charbonnel & Talon, 2005

27 Successes and caveats of present-day models of low and intermediate-mass stars Asteroseismology with Kepler has revolutionized our view of red giant stars X RGB stars Δ Clump stars 2nd Clump stars Mosser et al. 2012, A&A 548, A10 27

28 Successes and caveats of present-day models of low and intermediate-mass stars SubGiant and Red Giant Branches / Clump Inversion of the rotation gradient in subgiant branch stars from the Kepler fields The direction of the arrows indicates increasing age Deheuvels et al

29 Successes and caveats of present-day models of low and intermediate-mass stars Modern models including rotation and other non-standard transport processes give hints for improvement on the side of angular momentum evolution Cantiello et al. 2014

30 Uncertainties due to constitutive physics Impact of physical inputs within one code STAREVOL MESA Martins & Palacios 2013

31 Uncertainties due to constitutive physics Differences between publicly available grids Martins & Palacios 2013

32 Uncertainties due to constitutive physics Jones et al. (2015)

33 Uncertainties due to nuclear physics Large uncertainties on the nuclear reaction rates associated to He and C burning impact on stellar yields Helium burning Carbon burning Bennet et al West et al West et al. 2013

34 Uncertainties due to nuclear physics Large uncertainties on the nuclear reaction rates associated to He and C burning impact on stratification of white dwarfs S. Charpinet

35 Uncertainties due to nuclear physics Large uncertainties on the nuclear reaction rates associated to He and C burning impact on stratification of white dwarfs S. Charpinet Asteroseismology can help here

36 Uncertainties due to nuclear physics Large uncertainties on the nuclear reaction rates associated to He and C burning impact on stellar yields Pignatari et al West et al. 2013

37 The dynamical drivers of evolution Rotation modification of the stellar structure (centrifugal forces, non-sphericity, gravity darkening) modification of the mass loss transport of angular momentum and chemicals (macroscopic movements and hydrodynamical instabilities) Magnetic Fields modification of the stellar structure (Lorentz torque, magnetic energy, ohmic diffusion) transport of angular momentum and chemicals (MHD instabilities) Internal Gravity Waves transport of angular momentum (and chemicals) Thermohaline mixing transport of chemicals

38 Impact of rotation on structure and evolution Modification of evolutionary paths and fate of massive stars Georgy et al. 2012

39 Impact of rotation on structure and evolution Modification of evolutionary paths and fate of massive stars Groh et al. 2013

40 Impact of rotation on the nucleosynthesis Georgy et al. 2012

41 Impact of rotation on structure and evolution Meynet et al The choice of prescriptions impacts the evolutionary tracks advection nuclear microscopic processes diffusion Turbulence + merid. circ.

42 Impact of rotation on structure and evolution Chieffi & Limongi 2013

43 Impact of magnetic fields on structure and evolution Small percentage of massive stars with detected surface large-scale magnetic fields MiMes collaboration

44 Impact of magnetic fields on structure and evolution Magnetic fields introduced by means of instabilities - Taylor-Spruit instability - MRI Suijs et al. 2008

45 Impact of magnetic fields on structure and evolution Wheeler et al. 2015

46 Impact of magnetic fields on structure and evolution Wheeler et al. 2015

47 Impact of magnetic fields on structure and evolution Magnetic fields introduced by means of the exerted torque through winds Propose to spin down the core of massive stars Georgy et al. 2012

48 Summary Stellar structure and evolution : zero order known for evoltuion not driven by mass loss Disparity between the massive stars and less massive ones concerning evolutionary path and fate Large uncertainties from the point of view of models Clear impact of rotation and angular momentum transport processes on structure and evolution Necessity to improve the description / understanding of the dynamical processes

Solar surface rotation

Stellar rotation Solar surface rotation Solar nearsurface rotation Surface Doppler Schou et al. (1998; ApJ 505, 390) Rotational splitting Inferred solar internal rotation Near solidbody rotation of interior