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Tracing the wind structures in WR113

Tracing the wind structures in WR113. Alexandre David-Uraz (supervisor : Tony Moffat) Universit é de Montr éal. Outline. Brief theoretical context Introduction to CV Ser Spectroscopy and orbit Lamontagne et al. fit MOST photometry Clumping and wind collision

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Tracing the wind structures in WR113

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  1. Tracing the wind structures in WR113 • Alexandre David-Uraz (supervisor : Tony Moffat) • Université de Montréal

  2. Outline • Brief theoretical context • Introduction to CV Ser • Spectroscopy and orbit • Lamontagne et al. fit • MOST photometry • Clumping and wind collision • What’s next?

  3. Brief theoretical context • WR stars have a very high mass loss rate, typically M ~ 10-5 M/year • This rate cannot be explained by the star’s luminosity alone • A better understanding of the clumping phenomenon is crucial in solving this problem 

  4. Introduction to CV Ser WR113 = CV Ser = HD168206 , SB2 RA 18:19:07.36, DEC -11:37:59.2 (J2000) Galactic coordinates: l = 18.91º b = +1.75º Spectral types: WC8d + O8-9 IV v = 9.43 , b-v = +0.46 P = 29.704 ± 0.002 d, e = 0 (?) Goal: use MOST to probe structures in the WR wind as its companion shines through it at different orbital positions

  5. CV Ser – Field (DSS) 30'' x 30''

  6. CV Ser – Optical spectroscopy (OMM) CIII 4650 CIII 5696 CIV 5806 HeII 4686 HeI 5876

  7. CV Ser – Orbit (Massey & Niemela, 1981)

  8. CV Ser – Radial velocity plot (DAO)

  9. CV Ser – Radial velocity plot (DAO + OMM)

  10. Orbit of the O star?

  11. “Shift and add” method With the right orbit, it should be possible to separate each component’s individual spectrum with reasonable precision

  12. Previous g-b photometry leading to i, dM/dt & MWR, MO (Lamontagne et al. 1996)

  13. CV Ser light curve (Lamontagne et al., 1996)

  14. Hjellming & Hiltner (1963)

  15. OMG!

  16. CV Ser light curve (MOST)

  17. Other light curves from the same field

  18. Instrumental effects – HD 168112 Drift : (1.17±0.09)*10-4 mag/d

  19. Instrumental effects – MY Ser Drift : (5.4±0.1)*10-4 mag/d

  20. Instrumental effects – CV Ser Drift : (2.8±0.5)*10-4 mag/d Drift : (1.2±0.3)*10-4 mag/d

  21. Lamontagne et al. fit applied to the MOST light curve

  22. Lamontagne et al. fit “applied” to the other eclipse...

  23. Random variations due to clumping?

  24. Spectroscopic signs of clumping

  25. How do the clumps affect the light curve? (an artist’s vision) O Phase ~ 0 Phase ~ 0.25 O WR O Vers l’observateur Phase ~ 0.5

  26. Wind collision (Bartzakos et al. 2001) Lührs model

  27. Excess emission (CIII 5696) in a WC4 + O9 binary

  28. Excess emission in CV Ser (CIII 5696)

  29. What’s next? Fourier analysisin order to find pulsations in the star or itswind Waveletanalysisin order to findrandom variations due to the clumping Linkingthese variations to spectroscopic changes Establishingthe phase dependancyof these variations Putting together a model of the clumpingphenomenon A new observation campaignisscheduled for June/July 2010, both on the MOST spacetelescope and the spectrometerat OMM

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