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Combining observational techniques to constrain convection in evolved massive star models

Published online by Cambridge University Press:  23 January 2015

C. Georgy
Affiliation:
Astrophysics group, Lennard-Jones Laboratories, EPSAM, Keele University, Staffordshire ST5 5BG, UK email: [email protected]
H. Saio
Affiliation:
Astronomical Institute, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
G. Meynet
Affiliation:
Geneva Observatory, University of Geneva, Maillettes 51, CH-1290 Versoix, Switzerland
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Abstract

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Recent stellar evolution computations indicate that massive stars in the range ~ 20-30 M are located in the blue supergiant (BSG) region of the Hertzsprung-Russell diagram at two different stages of their life: immediately after the main sequence (MS, group 1) and during a blueward evolution after the red supergiant phase (group 2). From the observation of the pulsationnal properties of a subgroup of variable BSGs (α Cyg variables), one can deduce that these stars belongs to group 2. It is however difficult to simultaneously fit the observed surface abundances and gravity for these stars, and this allows to constrain the physical processes of chemical species transport in massive stars. We will show here that the surface abundances are extremely sensitive to the physics of convection, particularly the location of the intermediate convective shell that appears at the ignition of the hydrogen shell burning after the MS. Our results show that the use of the Ledoux criterion to determine the convective regions in the stellar models leads to a better fit of the surface abundances for α Cyg variables than the Schwarzschild one.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2015 

References

Bresolin, F., Pietrzyński, G., Gieren, W., et al. 2004, ApJ 600, 182Google Scholar
de Jager, C., Nieuwenhuijzen, H., & van der Hucht, K. A. 1988, A&AS 72, 259Google Scholar
Ekström, S., Georgy, C., Eggenberger, P., et al. 2012, A&A 537, A146Google Scholar
Firnstein, M. & Przybilla, N. 2012, A&A 543, A80Google Scholar
Fraser, M., Dufton, P. L., Hunter, I., & Ryans, R. S. I. 2010, MNRAS 404, 1306Google Scholar
Georgy, C. 2012, A&A 538, L8Google Scholar
Georgy, C., Ekström, S., Eggenberger, P., et al. 2013, A&A 558, A103Google Scholar
Georgy, C., Ekström, S., Meynet, G., et al. 2012, A&A 542, A29Google Scholar
Georgy, C., Saio, H., & Meynet, G. 2014, MNRAS 439, L6Google Scholar
Kaltcheva, N. & Scorcio, M. 2010, A&A 514, A59Google Scholar
Kaufer, A., Stahl, O., Wolf, B., et al. 1997, A&A 320, 273Google Scholar
Kaufer, A., Stahl, O., Wolf, B., et al. 1996, A&A 305, 887Google Scholar
Kudritzki, R.-P., Urbaneja, M. A., Bresolin, F., et al. 2008, ApJ 681, 269Google Scholar
Leitherer, C. & Wolf, B. 1984, A&A 132, 151Google Scholar
Markova, N. & Puls, J. 2008, A&A 478, 823Google Scholar
Martins, F. & Palacios, A. 2013, A&A 560, A16Google Scholar
Meakin, C. A. & Arnett, D. 2007, ApJ 667, 448Google Scholar
Moravveji, E., Guinan, E. F., Shultz, M., Williamson, M. H., & Moya, A. 2012, ApJ 747, 108Google Scholar
Percy, J. R., Palaniappan, R., Seneviratne, R., Adelman, S. J., & Markova, N. 2008, PASP 120, 311Google Scholar
Przybilla, N., Firnstein, M., Nieva, M. F., Meynet, G., & Maeder, A. 2010, A&A 517, A38+Google Scholar
Richardson, N. D., Morrison, N. D., Kryukova, E. E., & Adelman, S. J. 2011, AJ 141, 17Google Scholar
Saio, H., Georgy, C., & Meynet, G. 2013, MNRAS 433, 1246CrossRefGoogle Scholar
Schiller, F. & Przybilla, N. 2008, A&A 479, 849Google Scholar
Sterken, C. 1977, A&A 57, 361Google Scholar
Sterken, C., Arentoft, T., Duerbeck, H. W., & Brogt, E. 1999, A&A 349, 532Google Scholar
van Leeuwen, F., van Genderen, A. M., & Zegelaar, I. 1998, A&AS 128, 117Google Scholar
Vanbeveren, D., De Donder, E., van Bever, J., van Rensbergen, W., & De Loore, C. 1998, New. Astron. 3, 443Google Scholar
Viallet, M., Meakin, C., Arnett, D., & Mocák, M. 2013, ApJ 769, 1CrossRefGoogle Scholar