VLT-FLAMES Tarantula Survey Alex de Koter University of Amsterdam & KU Leuven C.J. Evans (PI), W.D. Taylor, V. Hénault-Brunet, H. Sana, A. de Koter (O-star coordinator), S. Simón- Díaz, G. Carraro, T. Bagnoli, N. Bastian, J.M. Bestenlehner, A.Z. Bonanos, E. Bressert, I. Brott, M.A. Campbell, M. Cantiello, J.S. Clark, E. Costa, P.A. Crowther, S.E. de Mink, E. Doran, P.L. Dufton (B-star coordinator), P.R. Dunstall, K. Friedrich, M. Garcia, M. Gieles, G. Gräfener, A. Herrero, I.D. Howarth, R. G. Izzard, N. Langer, D.J. Lennon, J. Maíz Apellániz, N. Markova, F. Najarro, J. Puls, O.H. Ramirez, C. Sabín-Sanjulián, S.J. Smartt, V.E. Stroud, J.Th. van Loon, J.S. Vink, N.R. Walborn VLT-FLAMES Tarantula Survey PI: C. Evans Main catalogues Dynamics of the central region 1. Observing campaign and YSOs (Evans+2011) 11. Evidence for cluster rotation 2. Spectral typing & special categories (Walborn+2014) (Hénault-Brunet+ 2012a) 20XX) 12. R136 is virialized (Hénault-Brunet+ 2012b) 20XX) Individual objects Population properties 3. VFTS 016: most massive runaway star (Evans+2010) 13-14. Spin of the single O & B stars 4. R139: most massive evolved O-star pair (Taylor+2011) (Dufton+ 2013, Ramírez-Agudelo+2013) 4. VFTS 102: fastest spinning O star (Dufton+2011) 15. Spin of O star primaries (Ramírez-Agudelo+ in prep) 4. VFTS 698: peculiar B[e] supergiant (Dunstall+2012) 16-17. Multiplicity of the O & B stars (Sana+2013, Dunstall+2015) 5. VFTS 682: a 150 M star in appartent isolation (Bestenlehner+2011) 18. Feedback (Doran+2013) 6. VFTS 822: candidate Herbig B[e] star (Kalari+2014) 20XX) 7. VFTS 352: most massive overcontact binary (Almeida+ in prep) 8. VFTS 399: X-ray bright emission line star (Clark+2015) VLT-FLAMES Tarantula Survey PI: C. Evans Interstellar Medium Single & binary evolution 19. DIBs and S I (van Loon+2013) 30. Bayesian tool for testing evolution (Schneider+ 2014) 20. Optical & NIR extinction law (Maíz Apellániz+2014) 31. Rotation of very massive stars (Köhler+ 2015) 32. Effects of binary interaction on rotation Sub-populations (de Mink+ 2013) 20XX) 21. Isolated high-mass stars (Bressert+2011) 22. Wind properties at top of main sequence (Bestenlehner+2014) 23. Nature of O Vz stars (Sabín-Sanjulián+2014 24-25. Properties of O stars (Sabín-Sanjulián+ in prep; Ramírez-Agudelo+ in prep) 26-27. Nitrogen abundances of O stars (Grin+ in prep., Sabín-Sanjulián+ in prep) 28. Classifications & RV of B stars (Evans+ 2015) 29. Properties of B supergiants (McEvoy+ 2015) VLT-FLAMES Tarantula Survey PI: C. Evans (Evans et al. 2011) I will tell you … what it is, what it is not, and what it never will be 185 x 146 pc VLT-FLAMES Tarantula Survey PI: C. Evans (Evans et al. 2011) • Multi-epoch spectroscopy of over 800 B stars, O stars, Wolf-Rayet stars massive stars in 30 Doradus 68 56 – 360 O-type stars (complete save for high AV) – 430 B-type stars 69 00 • Observations: 04 − FLAMES: 132 MEDUSA fibers feed 08 the Giraffe spectrometer 12 − No color cut 16 − V < 17 mag 40m 39m 38m 5h37m − 15” (4 pc) exclusion radius from R136a − 6 to 8 epochs - 22,000 spectra: 3980-5050 Å + Hα VLT-FLAMES Tarantula Survey PI: C. Evans (Evans et al. 2011) • Multi-epoch spectroscopy of over 800 B stars, O stars, Wolf-Rayet stars massive stars in 30 Doradus 68 56 – 360 O-type stars (complete save for high AV) – 430 B-type stars 69 00 • Characteristics: 04 − One of largest concentrations of massive 08 stars in Local Group 12 − Bright H II region with rich set of populations 16 − Closest unobscured view of young starburst 40m 39m 38m 5h37m − Template to understand distant star-forming galaxies VLT-FLAMES Tarantula Survey PI: C. Evans (Evans et al. 2011) • Multi-epoch spectroscopy of over 800 B stars, O stars, Wolf-Rayet stars massive stars in 30 Doradus 68 56 – 360 O-type stars (complete save for high AV) – 430 B-type stars 69 00 • Scientific goals: 04 − Role of stellar spin, mass loss, 08 overshooting & multiplicity in evolution 12 − Census of the nearest young starburst 16 − Starformation history of the region 40m 39m 38m 5h37m − Dynamics of the region Westerlund 1 (Clark et al. 2015) Tarantula Nebula (30 Dor) 7,3 x 7,3 pc 175 x 146 pc 175 x 146 pc Formed in splendid isolation … unlike 30 Dor Near instantaneous starburst … unlike 30 Dor Cluster core easily probed … unlike 30 Dor Unprecedented cohort of Yellow Hypergiants & Red Supergiants … unlike 30 Dor Formation of a proto-globular cluster in the Local Universe … unlike 30 Dor Westerlund 1 (Clark et al. 2015) Tarantula Nebula (30 Dor) 2,0 x 2,0 pc Crowther et al. in prep 175 x 146 pc 175 x 146 pc Formed in splendid isolation … unlike 30 Dor Near instantaneous starburst … unlike 30 Dor Cluster core easily probed … unlike 30 Dor Unprecedented cohort of Yellow Hypergiants & Red Supergiants … unlike 30 Dor Formation of a proto-globular cluster in the Local Universe … unlike 30 Dor Westerlund 2 Tarantula Nebula (30 Dor) VFTS 682 Most massive binary (R144, Minit total ~ 400 M) − Sana et al. 2013 Most massive star outside of dense cluster core (VFTS 682, Minit ~ 200 M) − Bestenlehner et al. 2011 Most massive star (R136a1, Minit ~ 320 M) − Crowther et al. 2010 Fastest spinning massive star (VFTS 102, vrot ~ 600 km/s) − Dufton et al. 2013 Most massive over-contact binary (VFTS 352, 27+27 M) − Almeida et al. 2015 Topics Aspects of the outcome of formation: spin distribution Binaries are everywhere, even when to try to get rid of them Formation of Massive Stars Outcome of Formation - IMF - Multiplicity properties - Spin distribution - Magnetic field distribution Formation Evolution End products The Great Unknown t = 0 time ZAMS Take away O-stars are born spinning slowly, up to 0.2-0.3 vcrit, which is not explained by formation theories Population of presumed single massive stars “polluted” with post-interaction binaries Evidence for this can be found in − spin distribution − surface nitrogen enrichment Evolution of the spin rate along the main-sequence 60 40 30 20 15 Vink et al. (2010), showing LMC tracks from Brott et al. (2011) So, current spin distribution close to initial spin distribution Incidence of binary products mergers: 8% semi-detached systems: 3% companions after Roche- lobe overflow: single: 17% 22% evolution & binary interaction pre-interaction binaries: 50% Conditions at birth Assuming continuous star formation from spectroscopic analysis Sana et al. 2012 De Mink et al. (2014) semi-detached systems: companions after 8% mass transfer: 4% % 42 : n o ti mergers: c a r 15% e t n i y r single: a companions n i 39% b after mass f o transfer: s t c 27% pre-interaction u d o binaries: 88% r p pre-interaction binaries:19% a) Apparently single b) Detectable as binary -1 -1 ( * < 10 km s ) ( * > 10 km s ) De Mink et al. (2014) Spin properties of 212 presumed single O-type stars Low-velocity peak High-velocity tail Ramírez-Agudelo et al. 2013 Evolution of rotating massive stars LMC Brott et al. (2011) Spin properties of 212 presumed single O-type stars Low-velocity peak High-velocity tail Ramírez-Agudelo et al. 2013 Impact of binarity on the spin distribution of O stars de Mink et al. 2013 Ramirez-Agudelo et al. 2013 Take away Most O stars have vrot < 200 km/sec impact of rotation on evolution in HRD is limited About 20% of O star population have vrot > 300 km/sec Rotation impacts HRD evolution (dramatically) Compatible with binary evolution simulation semi-detached systems: companions after semi-detached systems:8% companionsmass transfer: after 4% % 8% 42 mass transfer: 4% : n % 4o2 :ti mergers: nc oa ti r mergers:15% c e a t r n 15% e i t n y i r single: a y r companions n single: i a 39% b companions n i after mass f 39% b o after mass f transfer: s o t transfer: c s t 27% pre-interaction u c d 27% pre-interaction u o binaries: 88% d r o p binaries: 88% r p pre-interaction pre-interaction binaries:19% binaries:19% a) a)Apparently Apparently single single b) Detectableb) Detectable as binary as binary -1 -1 -1 -1 ( *( < 10* < km10 kms ) s ) ( * > 10( km* > 10s ) km s ) De Mink et al. (2014) Spin distribution of O-type spectroscopic binaries 114 primaries (SB1 and SB2); 31 secondaries (SB2) Sample large enough to define sub-sets, e.g. Primaries & secondaries of SB2’s (31) low-ΔRV sources (85) Primaries & secondaries Ramírez-Agudelo et al. in prep SB2’s mostly large-ΔRV sources, which is selection effect as these are most easily recognised as being double lined They are thus close binaries, which may have synchronized with their orbital period Low-ΔRV sources These are mostly wide binaries, i.e. systems that have not yet interacted and have preserved their initial spin similar to single stars For vrsini < 170 km/s the distributions are about consistent with being drawn from same parent population 10.4 ± 1.9% of presumed singles spin faster than 300 km/s High velocity tail essentially For low-ΔRV sources this is 2.6 ± missing in wide binary sample 1.8% Low-ΔRV sources Presumed-single star sample Complete binary sample Low-ΔRV sources Markov chain Monte Carlo method to reconstruct intrinsic (current) rotational velocity distribution Take away In wide binaries, the high-velocity tail seen in presumed-single sample is missing supports the hypothesis that rapidly spinning O stars have binary interaction history Rapidly spinning O stars might not form at all… Impact of binarity on the spin distribution of O stars de Mink et al.