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Selma E. de Mink

Nate Bastian Rob Izzard Norbert Langer Onno Pols. Multiple populations in globular clusters. massive binaries and stellar rotation . Selma E. de Mink. Utrecht  Bonn (Jun 2010)  STScI (Nov 2010). Introduction. . .. not so simple as we thought they were .

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Selma E. de Mink

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  1. Nate Bastian Rob Izzard Norbert Langer OnnoPols Multiple populations in globular clusters massive binaries and stellar rotation Selma E. de Mink S.E. de Mink Utrecht  Bonn (Jun 2010) STScI (Nov 2010)

  2. Introduction ... notsosimple as we thoughttheywere... S.E. de Mink

  3. Evidence for multiple populations  review talk by S. Larsen • Multiple populations that differ in • composition • age (?) • Stellar abundances • e.g. Cohen+78, Gratton+04, Carretta+09ab • Color magnitude diagrams • e.g. Bedin+04, D’Antona+05, Piotto+07 S.E. de Mink

  4. Evidence for age spread ? • Multiple populations that differ in • composition • age (?) • Stellar abundances • e.g. Cohen+78, Gratton+04, Carretta+09ab • Color magnitude diagrams • e.g. Bedin+04, D’Antona+05, Piotto+07 • Stellar abundances • e.g. Cohen+78, Gratton+04, Carretta+09ab • Color magnitude diagrams • e.g. Bedin+04, D’Antona+05, Piotto+07 • Spread around turn-off in intermediate age clusters • age spread ~ 200 Myr? • (e.g. Goudfrooij+09, Mackey+08, Milone+09 ) •  stellar rotation? • Bastian & De Mink (2009) S.E. de Mink

  5. How to form multiple populations? 1. Initialcloudwith “normal” composition 6. The multiple populations we seetoday. S.E. de Mink

  6. Simplified formation scenario 1. Initialcloudwith “normal” composition 2. Formation of the firstgeneration of stars 6. The multiple populations we seetoday. S.E. de Mink

  7. Simplified formation scenario 1. Initialcloudwith “normal” composition 2. Formation of the firstgeneration of stars 3. “Massive ”stars ejectpro-cessedmaterial 6. The multiple populations we seetoday. S.E. de Mink

  8. Simplified formation scenario 1. Initialcloudwith “normal” composition 2. Formation of the firstgeneration of stars 3. “Massive ”stars ejectpro-cessedmaterial ? ? 4. Polluting the cluster 5. Forming a secondgeneration. 6. The multiple populations we seetoday. S.E. de Mink

  9. Who are thepolluters? They must eject material … Challenges Candidates • Composition • Amount • e.g. Gratton+04, D’Antona+Caloi08 • Massive AGB stars: • e.g. Cottrell+DaCosta+81, • Ventura+01 • Spin stars: • fast rotating massive stars • e.g. Decresin+07 • … at low velocity to remain within the potential well of the cluster • … processed by H-burning at high temperature • e.g. Prantzos+07 S.E. de Mink

  10. Mass budget Kroupa 2001 S.E. de Mink

  11. Anomalous IMF ? Strong preferential loss of normal stars ? External pollution ? Mass budget Alterative source? Assuming all 4-9 Msun stars are single and contribute Assuming all stars rotate fast! > 80% break-up Ciotti+91, D’Ercole+08 Prantzos+Charbonnel06, Decressin+07 S.E. de Mink

  12. Massivebinaries Bonn/Utrecht binary stellar evolution code • Stellar evolution, mass loss, extensivenucleosynthetic network, binary interaction,tides,magnetic fields, rotation, … Langer+9*, Heger+00, Petrovic+05, Yoon+06, De Mink, et al. (2009b) S.E. de Mink

  13. InteractingBinaries • The most massive star enrichesits inner layerswithproducts of proton capturereactions. S.E. de Mink

  14. De Mink et al. (2009a) InteractingBinaries He core Mg↓Al↑ “Strongly” processed O↓Na↑ “Mildly” processed C↓N↑ Unprocessed Li↓ • The most massive star enrichesits inner layerswithproducts of proton capturereactions. S.E. de Mink

  15. De Mink et al. (2009a) InteractingBinaries Unprocessed • The most massive star enrichesits inner layerswithproducts of proton capturereactions. • Whenitexpandsbeyond a critical radius, it is strippedfromitsentireenvelope. • The firstnon-enrichedlayers are accretedby the companion. S.E. de Mink

  16. De Mink et al. (2009a) Interacting Binaries Unprocessed Mildlyprocessed Stronglyprocessed • The most massive star enriches its inner layers with products of proton capture reactions. • When its expands beyond a critical radius, the is stripped from its entire envelope. • The first non-enriched layers are accreted by the companion. • Processed material is shedded from the system at low velocity. S.E. de Mink

  17. Observational evidence e.g. Iben+Livio93 Refsdal+74, Sarna93, deGreve+Linnell94, Figueiredo+94, vanRensbergen+06 De Mink, Pols, Hilditch (2007) • “Show case”: Massive interacting binary: RY Scuti • Circum-binary disk (1AU), Nebula (2000 AU) • Rich in He, N, Poor in O, C • Velocity 30-70 km/s • Dust and clumps Gehrz+01, Smith+01,02, Grundstrom+07 • Post-interaction • Cataclysmic variables, X-ray binaries, double white dwarfs, double neutron stars, Planetary nebulae with binary cores • Interacting binaries • Algol type systems • Tests from eclipsing binaries S.E. de Mink

  18. Observational evidence e.g. Iben+Livio93 Refsdal+74, Sarna93, deGreve+Linnell94, Figueiredo+94, vanRensbergen+06 De Mink, Pols, Hilditch (2007) • Evidenceformass loss frombinaries • comes from a widevariety of observedsystems • seems to be a commonphenomenon. • “Show case”: Massive interacting binary: RY Scuti • Circum-binary disk (1AU), Nebula (2000 AU) • Rich in He, N, Poor in O, C • Velocity 30-70 km/s • Dust and clumps Gehrz+01, Smith+01,02, Grundstrom+07 • Post-interaction • Cataclysmic variables, X-ray binaries, double white dwarfs, double neutron stars, Planetary nebulae with binary cores • Interacting binaries • Algol type systems • Tests from eclipsing binaries S.E. de Mink

  19. Theoretical “evidence” With courtesy of D. Bisikalo e.g. Nazarenko+Glazunova06, Zhilkin+Bisikalo09 S. Mohammed (thesis work) Ultich+Burger76, Flannery+Ulrich77, … Wellstein+01, De Mink + 2007 Packet81, Barai+04, Wellstein 00 Petrovic+05 • Hydro simulations • Evolutionary calculations • Expansion -> contact • Spin up S.E. de Mink

  20. Proof of principle De Mink et al. (2009a) Utrecht/Bonn binary code • Stellar evolution, mass loss, extensivenucleosynthetic network, binary interaction,tides,magnetic fields, rotation, … Surface abundance Typical massive binary - 20 Msun+15 Msun - Mass transfer starts during H-shell burning (Case B) • Transferred: 12 Msun, Accreted 1.5 Msun Ejecta are • enriched: He, N, Na, Al • depleted: C, O S.E. de Mink Ejected mass (Msun)

  21. Furtherevolution • Wat about the companion? •  spin star •  reverse mass transfer • Watabout the initial rotation rate? •  internal mixing even more ejecta even more enriched S.E. de Mink

  22. Mass Budget “back of the envelope” estimate S.E. de Mink

  23. Binary fraction • In nearby OB associations • close binary fraction ~ 50% among massive stars Mason+09, Sana+10 In the cores of proto globular clusters? even higher? • Initial/quick Mass segregation • Early core collapse • Dynamical interactions of stars and gas (dissipative!) collisions Sills+Glebbeek10 S.E. de Mink

  24. De Mink et al. (2009a) Binaries as sources of enrichment • Without commonly made assumptions • Normal IMF • No a very high fraction of veryfast rotators • No externalpollution • No extreme preferential loss of 1st generation stars S.E. de Mink

  25. De Mink et al. (2009a) Binaries as sources of enrichment MassiveBinaries: Assumingthat the complete envelope is processed and returned and that all stars above 10 Msun are in interactingbinaries S.E. de Mink

  26. De Mink et al. (2009a) Binaries as sources of enrichment MassiveBinaries: Assumingthat the complete envelope is processed and returned and that all stars above 10 Msun are in interactingbinaries Binaries can return more processed mass than AGB and spin stars together. S.E. de Mink

  27. De Mink et al. (2009a) Binaries as sources of enrichment Massive Binaries: Assuming that the complete envelope is processed and returned and that all stars above 10 Msun are in interacting binaries Intermediate mass binaries: Lower mass stars may also provide processed material showing some of the anticorrellations produced at lower T. Binaries can return more processed mass than AGB and spin stars together. S.E. de Mink

  28. Conclusion S.E. de Mink

  29. Conclusion Interacting stars are promisingsources forselfenrichment of globular clusters • Mass stripping due to binary: rather common in the center of massive young clusters • Interacting stars can eject material • processed by H-burning • at low velocities • in large amounts • More important than AGB stars and spin stars?? at least in terms of the amount of ejecta • Relieve of the need for extreme additional assumptions! • a top heavy IMF • extreme polution or preferential mass loss

  30. More information “The effect of stellar rotation CMD’s: on the apparent presence of multiple populations in intermediate age starclusters” Bastian &De MInk MNRAS 398, 11 (2009) “Massive binaries as the source of abundance anomalies in globular clusters” De Mink, Pols, Langer, Izzard A&A 507, 1 (2009) Acknowledgements: fruitful interaction with the star cluster & stellar evolution groups in Utrecht & Bonn (Cantiello, Chies-Santos, Decressin, Glebbeek, Kruijssen, Larsen, Silva-Villa, van Veelen) S.E.deMink@gmail.com S.E. de Mink

  31. Some thoughts on bimodal red clumps S.E. de Mink • Stellar properties during helium burning • Luminosity: <-> core mass <-> initial mass • Temperature/color: <-> details in internal chemical profile • “blue loops act as a magnifying glass” • Rotation • affects the internal chemical profile • increases the size of the core • increases the lifetime: about 10% longer Effect II + III enhance each other: more massive fast rotators (with larger core masses, 2x) will be at the same time at the red clump as less massive slow rotators (with smaller core masses)

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