[en] Since the early days of helioseismology, adiabatic models have shown their limits for a precise fitting of individual oscillation frequencies. This discrepancy, which also exists for solar-type stars, is known to originate near the surface superadiabatic convective region where the interaction between oscillations and convection is likely to have a large effect on the frequencies. We present an asteroseismic study to address the adequacy of time-dependent convection (TDC) non-adiabatic models to better reproduce the observed individual frequencies. We select, for this purpose, three solar-like stars, in addition to the Sun, to which we fit the observed frequencies in a grid of TDC non-adiabatic models. The best model selection is done by applying a maximum likelihood method. The results are compared to pure adiabatic and near-surface corrected adiabatic models. We show that, first, TDC models give very good agreement for the mode frequencies and average lifetimes. In the solar case, the frequency discrepancy is reduced to <1.75 μHz over 95 per cent of the modes considered. Secondly, TDC models give an asteroseismic insight into the usually unconstrained ad hoc stellar parameters, such as the mixing-length parameter α[SUB]MLT[/SUB].
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Grigahcène, A.; Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
Dupret, Marc-Antoine ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Sousa, S. G.; Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
Monteiro, M. J. P. F. G.; Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal ; Departamento de Física e Astronomia, Faculdade de Ciências da Universidade do Porto, 4169-007 Porto, Portugal
Garrido, R.; Instituto de Astrofísica de Andalucía, CSIC, PO Box 3004, 18080 Granada, Spain
Scuflaire, Richard ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Evol. et stabilité des étoiles et des amas d'étoiles (ESEA)
Gabriel, M.; Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17-B 4000 Liège, Belgium)
Language :
English
Title :
Towards an effective asteroseismology of solar-like stars: time-dependent convection effects on pulsation frequencies
Bahcall J. N., Pinsonneault M. H., Wasserburg G. J., 1995, Rev. Modern Phys., 67, 781
Balmforth N. J., 1992a, MNRAS, 255, 603
Balmforth N. J., 1992b, MNRAS, 255, 632
Balmforth N. J., Gough D. O., 1990, Solar Phys., 128, 161
Bazot M., Bouchy F., Kjeldsen H., Charpinet S., Laymand M., Vauclair S., 2007, A&A, 470, 295
Belkacem K., Goupil M.-J., Dupret M.-A., Samadi R., Baudin F., Noels A., Mosser B., 2011, A&A, 530, A142
Brandão I. M. et al., 2011, A&A, 527, A37
Broomhall A.-M., Chaplin W. J., Davies G. R., Elsworth Y., Fletcher S. T., Hale S. J., Miller B., New R., 2009, MNRAS, 396, L100
Bruntt H. et al., 2010, MNRAS, 405, 1907
Chaplin W. J., Houdek G., Karoff C., Elsworth Y., New R., 2009, A&A, 500, L21
Christensen-Dalsgaard J., 1988, Seismology of the Sun and Sun-Like Stars, 286, 431
Christensen-Dalsgaard J., Dappen W., Lebreton Y., 1988, Nat, 336, 634
Cox A. N., Guzik J. A., Kidman R. B., 1989, ApJ, 342, 1187
Dupret M. A., 2001, A&A, 366, 166
Dupret M.-A., Grigahcène A., Garrido R., Gabriel M., Scuflaire R., 2005, A&A, 435, 927
Dupret M. A., Barban C., Goupil M.-J., Samadi R., Grigahcène A., Gabriel M., 2006, in Fletcher K., Thompson M., eds, Proc. SOHO 18/GONG 2006/HELAS I, ESA SP-624, Beyond the Spherical Sun. Sheffield, p. 97
Dziembowski W. A., Paterno L., Ventura R., 1988, A&A, 200, 213
Gabriel M., 1996a, A&A, 309, 939
Gabriel M., 1996b, Bull. Astron. Soc. India, 24, 233
Gabriel M., 2000, A&A, 353, 399
Gabriel M., Carlier F., 1997, A&A, 317, 580
Gough D. O., 1977, ApJ, 214, 196
Gray D. F., 1992, Cambridge Astrophys. Ser. Vol. 20, The Observation and Analysis of Stellar Photospheres. Cambridge Univ. Press, Cambridge
Grigahcène A., Dupret M.-A., Gabriel M., Garrido R., Scuflaire R., 2005, A&A, 434, 1055
Kjeldsen H., Bedding T. R., Christensen-Dalsgaard J., 2008, ApJ, 683, L175
Li L. H., Robinson F. J., Demarque P., Sofia S., Guenther D. B., 2002, ApJ, 567, 1192
Nordlund A., 1985, Solar Phys., 100, 209
Rosenthal C. S., Christensen-Dalsgaard J., Nordlund Å., Stein R. F., Trampedach R., 1999, A&A, 351, 689
Roxburgh I. W., Vorontsov S. V., 2003, A&A, 411, 215
Scuflaire R., Théado S., Montalbán J., Miglio A., Bourge P.-O., Godart M., Thoul A., Noels A., 2008, Ap&SS, 316, 83
Sousa S. G., Santos N. C., Israelian G., Mayor M., Monteiro M. J. P. F. G., 2007, A&A, 469, 783
Sousa S. G. et al., 2008, A&A, 487, 373
Sousa S. G., Santos N. C., Israelian G., Lovis C., Mayor M., Silva P. B., Udry S., 2011, A&A, 526, A99
Steffen M., Ludwig H.-G., Kruess A., 1989, A&A, 213, 371
Stein R. F., Nordlund Å., 1991, Lecture Notes in Physics Vol. 388, Challenges to Theories of the Structure of Moderate-Mass Stars. Springer-Verlag, Berlin, p. 195
Stein R. F., Nordlund A., 1994, in Rabin D. M., Jefferies J. T., Lindsey C., eds, Proc. IAU Symp. 154, Infrared Solar Physics. Kluwer, Dordrecht, p. 225
Stellingwerf R. F., 1982, ApJ, 262, 330
Teixeira T. C. et al., 2009, A&A, 494, 237
Trampedach R., Stein R. F., 2011, ApJ, 731, 78
Xiong D. R., Cheng Q. L., Deng L., 1997, ApJS, 108, 529