Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-07T01:54:38.688Z Has data issue: false hasContentIssue false
  • English
  • Français

Observational Evidence for the Stratification of Chemical Abundances in Stellar Atmospheres

Published online by Cambridge University Press:  26 May 2016

T. Ryabchikova ,
G. A. Wade  and
F. Leblanc
T. Ryabchikova
Affiliation:
Institute of Astronomy, Russian Academy of Sciences, Pyatnitskaya 48, 119017 Moscow, Russia Institute for Astronomy, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria
G. A. Wade
Affiliation:
Department of Physics, Royal Military College of Canada, PO Box 17000, Station “Forces” Kingston, Ontario, K7K 7B4, Canada
F. Leblanc
Affiliation:
Département de physique et d'astronomie, Université de Moncton, Moncton, New Brunswick, E1A 3E9, Canada

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present spectroscopic and photometric observational evidence for abundance stratification in stellar atmospheres. Attention is given to chemically peculiar (Ap) stars in which magnetic fields stabilize the atmosphere, allowing diffusion processes to establish abundance stratification during the early stages of star's life. The results of recent empirical modelling of chemically stratified atmospheres are briefly discussed, and a comparison is given with the predictions of self-consistent atmospheric models which include radiative diffusion.

The importance of abundance stratification analysis is demonstrated for rapidly oscillating (roAp) stars in which the amplitudes of the radial velocity pulsations are different for the lines of different elements in different ionization stages. We also demonstrate that chemical stratification has important effects on the Zeeman Stokes IQUV profiles of Ap stars, indicating that stratification must be taken into account in detailed modelling of their magnetic fields.

Type
Session E. Comparison with Observations
Information
Symposium - International Astronomical Union , Volume 210: Modelling of Stellar Atmospheres , 2003 , pp. 301 - 312
Copyright
Copyright © Astronomical Society of the Pacific 2003 

References

Alecian, G. 1982, A&A, 107, 61 Google Scholar
Alecian, G., & Stift, M. J. 2002, A&A, 387, 271 Google Scholar
Aret, A., & Sapar, A. 2002, AN, 323, 21 Google Scholar
Atutov, S. N., & Shalagin, A. M. 1988, Sov. Astron. Let, 14, 284 Google Scholar
Babel, J. 1992, A&A, 258, 449 Google Scholar
Babel, J. 1994, A&A, 283, 189 Google Scholar
Bohlender, D.A. 1989, ApJ, 346, 459 CrossRefGoogle Scholar
Bohlender, D.A., Dworetsky, M. M., & Jomaron, C. M. 1998, ApJ, 504, 533 CrossRefGoogle Scholar
Bonifacio, P., Castelli, F., & Hack, M. 1995, A&AS, 110, 441 Google Scholar
Cowley, C.R., Ryabchikova, T.A., Kupka, F., Bord, D.J., Mathys, G., & Bidelman, W.P. 2000, MNRAS, 317, 299 CrossRefGoogle Scholar
Cowley, C. R., Hubrig, S., Ryabchikova, T.A., Mathys, G., Piskunov, N., & Mittermayer, P. 2001, A&A, 367, 939 Google Scholar
Dreizler, S., & Wolff, B. 1999, A&A, 348, 189 Google Scholar
Farthmann, M., Dreizler, S., Heber, U., & Hunger, K. 1994, A&A, 291, 919 Google Scholar
Hack, M., Polosukhina, N. S., Malanushenko, V. P., & Castelli, F. 1997, A&A, 319, 637 Google Scholar
Hartoog, M. R., & Cowley, A. P. 1979, ApJ, 228, 229 CrossRefGoogle Scholar
Hauschildt, P.H., Allard, F., & Baron, E., 1999, ApJ, 512, 377 CrossRefGoogle Scholar
Hubrig, S., Castelli, F., & Mathys, G. 1999, A&A, 341, 190 Google Scholar
Hui-Bon-Hoa, A., LeBlanc, F., & Hauschildt, P.H. 2000, ApJ, 535, L43 CrossRefGoogle Scholar
Jamar, C., Macau-Hercot, D., Monfils, A., Thompson, G. I., Houziaux, L., & Wilson, R. 1976, Ultraviolet Bright-Star Spectrophotometric Catalogue, ESA SR-27 Google Scholar
Kalus, G., Johansson, S., Wahlgren, G. M., Leckrone, D.S., Thorne, A. P., & Brandt, J. C. 1998, ApJ, 494, 792 CrossRefGoogle Scholar
Kochukhov, O., & Ryabchikova, T. 2001a, A&A, 374, 615 Google Scholar
Kochukhov, O., & Ryabchikova, T. 2001b, A&A, 377, L22 Google Scholar
Kochukhov, O., & Piskunov, N. 2002, A&A, 388, 868 Google Scholar
Lanz, T., Artru, M.-C., Didelon, P., & Mathys, G. 1993, A&A, 272, 465 Google Scholar
LeBlanc, F., & Michaud, G. 1993, ApJ, 408, 251 CrossRefGoogle Scholar
Leckrone, D. S., Proffitt, C. R., Wahlgren, G. M., Johansson, S. G., & Brage, T. 1999, AJ, 117, 1454 CrossRefGoogle Scholar
Michaud, G. 1970, ApJ, 160, 641 CrossRefGoogle Scholar
Proffitt, C. R., Brage, T., Leckrone, D. S., Wahlgren, G. M., Brandt, J. C., & Sansonetti, C. J. 1999, ApJ, 512, 942 CrossRefGoogle Scholar
Pyper, D. M., & Adelman, S. J. 1985, A&AS, 59, 369 Google Scholar
Ryabchikova, T. A., Savanov, I.S., Malanushenko, V. P., & Kudryavtsev, D. O. 2001, ARep., 45, 382 Google Scholar
Ryabchikova, T., Piskunov, N., Kochukhov, O., Tsymbal, V., Mittermayer, P., & Weiss, W. W. 2002, A&A, 384, 545 Google Scholar
Savanov, I. S., Kochukhov, O. P., & Tsymbal, V. V. 2001, Ap, 44, 206 Google Scholar
Sigut, T. A. A. 2001a, ApJ, 546, L115 CrossRefGoogle Scholar
Sigut, T. A. A. 2001b, A&A, 377, L27 Google Scholar
Sigut, T. A. A., Landstreet, J. D., & Shorlin, S. L. S. 2000, ApJ, 530, L89 CrossRefGoogle Scholar
Smith, K.C. 1995, A&A, 297, 237 Google Scholar
Wade, G. A., Ryabchikova, T. A., Bagnulo, S., & Piskunov, N. 2001, in Magnetic Fields Across the Hertzsprung-Russell Diagram, ed. Mathys, G., Solanki, S. K., & Wickramasinghe, D. T., ASP Conf. Ser., 248, 341 Google Scholar
Wahlgren, G. M., & Hubrig, S. 2000, A&A, 362, L13 Google Scholar
Weiss, W.W., Rybachikova, T.A., Savanov, I., Piskunov, N., Tsymbal, V., Mittermayer, P., Martinez, P., Kochukhov, O., & Nesvacil, N. 2002, ASP Conf. Ser., 259, 280 Google Scholar
Woolf, V. M., & Lambert, D. L. 1999, ApJ, 521, 414 CrossRefGoogle Scholar
Zakharova, L. A., & Ryabchikova, T. A. 1996, 22, 152 Google Scholar