Evolution of massive binary stars

Norbert Langer (Bonn University)

ESO Garching, July 5, 2017 – p. 1

mass ↑ −→ our ignorance ⇑

G stars√

low chance to bebinary productMoe

√

M ≃ 0√

high internal

stability (β = 1)√

B fields ubiquitous

O stars√

high chance to bebinary productSana

√

self-evaporate√

at verge ofinstability

(β → 0)√

B fields sporadicAlecian

massive stars are so relevant√

SNe, GRBs, NSs, BHs√

determine state of ISM√

dominate chemical evolution

ESO Garching, July 5, 2017 – p. 2

Rotational mixing: early BV stars

Brott, Evans, Hunter et al. 2011, A&A, 530, A116

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Overshooting: Galactic sHRD

600 stars: distance- and reddening-independent

Castro, Fossati, Langer, Simon-Diaz, Schneider, Izzard, 2014, A&A, 570, L13

ESO Garching, July 5, 2017 – p. 4

Mass loss rates

Bestenlehner, Gräfener, Vink et al., A&A 570, A38Gräfener, Vink, de Koter, Langer, 2011, A&A, 535, A56

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Binary evolution

√

tides√

mass transfer√

common envelopeevolution

√

merger

ESO Garching, July 5, 2017 – p. 6

Tidal friction

Massive stars: radiative envelopes⇒ radiative damping → dynamical tide Zahn 1975, A&A, 41, 329

But: (shear-induced) turbulent viscosity maydominate

Toledano, Moreno, Koenigsberger, Detmers, Langer 2007, A&A, 461, 1057Moreno, Koenigsberger, Toledano, 2005, A&A, 437, 641

→ closer to tides in convective envelopes Zahn 1977, A&A, 57, 383

ESO Garching, July 5, 2017 – p. 7

Tidally dominated MS evolution

de Mink, Cantiello, Langer, Pols, Brott, Yoon, 2009, A&A, 497, 243

massive merging BHs! de Mink, Mandel, 2016, MNRAS, 460, 3545Marchant, Langer, Podsiadlowski, Tauris, Moriya, 2016, A&A, 588, A50

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Tidal spin-up of WR stars

Detmers, Langer, Podsiadlowski, Izzard 2008, A&A, 484, 831

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Mass transfer: rejuvenation?

Petrovic, Langer, van der Hucht, 2005, A&A, 435, 1013

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Spin-up!

de Mink, Langer, Izzard, Sana, de Koter, 2013, ApJ, 764, 166ESO Garching, July 5, 2017 – p. 11

Spin-up!

Ramirez-Agudelo, Sana, de Mink, et al., 2015, A&A, 580, A92

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Mass stripping → SNe Ibc

Yoon, Woosley, Langer, 2010, ApJ, 725, 940

Goetberg

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Merger: > 20%: where are they?

e�ectivelysingle

envelopestrippingenvelopestripping

merge

accretion & spin up or CE

accretion & spin up or CE

~29%

~24%

~14%

~33%

Sana, de Mink, Koter, Langer, et al., 2012, Science, 337, 444

Ohlmann et al., in prep.Glebbeek, Gaburov, Portegies Zwart, Pols, 2013, MNRAS, 434, 3497

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HD 148937 O6.5f?p: a smoking gun?

Langer, 2012, ARAA, 50, 107Leitherer, Chavarria-K., 1987, A&A, 175, 208

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Merger productsMS merger: blue stragglers Mathieu

Petermann, Langer, Castro, Fossati, 2015, A&A, 584, A54Schneider, Podsiadlowski, Langer, Castro, Fossati, MNRAS, 2016 457, 2355

post-MS merger: blue supergiant

Justham, Podsiadlowski, Vink, 2014, ApJ, 796, 121Braun, Langer, 1995, A&A, 297, 483

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B-field decay

Fossati, Schneider, Castro, Langer, Simon-Diaz, Mueller, de Koter, Morel, Petit, Sana, Wade, 2016, A&A, 592, A84ESO Garching, July 5, 2017 – p. 17

B-field decay: mass dependent

Potter, Chitre, Tout, 2012, MNRAS, 424, 2358Fossati+ 2016

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Common envelope evolution: models

established for low-mass stars (CVs, ...)not much known for massive stars ...

√

theoretically, even low mass CE ejection difficult

Ohlmann, Röpke, Pakmor, Springel, 2016, ApJ, 816, L9Clayton, Podsiadlowski, Ivanova, Justham, arXiv170508457

√

massive stars: unclear core/envelope boundaryenvelope binding could be large, but also verysmall (LBV) Kruckow, Tauris, Langer, Szecsi, Marchant, Podsiadlowski, 2016, A&A, 596, A58

ESO Garching, July 5, 2017 – p. 19

Common envelope evolution:observations

CEE occurs in massive binaries!√

15 NS-NS binaries, 7 with Porbit < 1.2 d

Antoniadis, Breton, Champion, ApJ, arXiv:1706.09438Tauris, Kramer, Freire, Wex, Janka, Langer, Podsiadlowski, Bozzo, Chaty, Kruckow, van den Heuvel,

√

ultra-stripped supernovae Tauris, Langer, Podsiadlowski, 2015, A&A, 451, 2123

√

LMBHBs? Fragos, McClintock, 2015, ApJ, 800, 17

√

However: no CEE in Galactic WR binaries!Shara, Crawford, Vanbeveren, Moffat, Zurek, Crause, 2017, MNRAS, 464, 2066

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M − LEddington relation

ESO Garching, July 5, 2017 – p. 21

M − LEddington relation

ESO Garching, July 5, 2017 – p. 22

M − LEddington relation

ESO Garching, July 5, 2017 – p. 23

M − LEddington relation

ESO Garching, July 5, 2017 – p. 24

Very massive star models

5.6

5.8

6

6.2

6.4

6.6

6.8

7

7.2

0 10 20 30 40 50 60

log(

L/L ⊙

)

Teff [kK]

60 M⊙

70 M⊙

80 M⊙

100 M⊙

150 M⊙

200 M⊙

300 M⊙

400 M⊙

500 M⊙

HD limit

ZAMS

Köhler, Langer, de Koter, de Mink, et al. 2015, A&A, 573, A71

ESO Garching, July 5, 2017 – p. 25

Inflation

-12

-10

-8

-6

-4

-2

0

2

0 20 40 60 80 100 120 140

log

dens

ity [g

m/c

c]

Radius [R⊙

]

86.41M⊙

eqb. model, log Teff=4.24 K, log (L/L⊙

)=6.27

Inflated envelope

Menv=10-3 M⊙

Density inversion

Sanyal, Grassitelli, Langer, Bestenlehner, 2015, A&A, 580, A20

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The Galactic sHRD

600 stars: distance- and reddening-independent

Castro, Fossati, Langer, Simon-Diaz, Schneider, Izzard, 2014, A&A, 570, L13

ESO Garching, July 5, 2017 – p. 27

Summary

√

stellar models: the higher the mass, the larger theuncertainty

√

uncertainties in single star physics affects binaryevolution model: mixing and mass loss

√

rejuvenation of mass gainers?√

spin-up of mass gainers!√

merger: B-field?√

B-field decay in massive stars√

CE-evolution occurs massive stars√

CE-evolution occurs in VMS?√

VMS: inflation & LBV mass lossESO Garching, July 5, 2017 – p. 28