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Ubatuba November 2005 2nd CoRoT Brazil δ Scuti and γ Dor stars in COROT Rafael Garrido IAA, Granada (Spain)

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Presentation on theme: "Ubatuba November 2005 2nd CoRoT Brazil δ Scuti and γ Dor stars in COROT Rafael Garrido IAA, Granada (Spain)"— Presentation transcript:

1 Ubatuba November nd CoRoT Brazil δ Scuti and γ Dor stars in COROT Rafael Garrido IAA, Granada (Spain)

2 Ubatuba Nov 20052nd CoRoT Brazil Current ground based observations Current ground based observations δ Scuti: 0.3 – 3 hours (p- and mixed modes) γ Doradus: 0.4 – several days (g-modes) both regimes? (Dupret et al A&A 414, L17) both regimes? (Dupret et al A&A 414, L17) and Solar like oscillations? (Samadi et al A&A 395, 563) and Solar like oscillations? (Samadi et al A&A 395, 563) Mode identification: Mode identification: Frequency differences: Sismo & Exo Frequency combinations: Sismo & Exo Colour information: Exo Frequency Ratio Method ( γ Dor) : Sismo & Exo

3 Ubatuba Nov 20052nd CoRoT Brazil FG Vir Current ground based observations Breger et al A&A 419, 695

4 Ubatuba Nov 20052nd CoRoT Brazil Breger et al A&A 419, 695 FG Vir Current ground based observations

5 Ubatuba Nov 20052nd CoRoT Brazil Current ground based observations Breger et al A&A 419, 695 FG Vir

6 Ubatuba Nov 20052nd CoRoT Brazil Breger et al A&A 419, 695 FG Vir Current ground based observations

7 Ubatuba Nov 20052nd CoRoT Brazil Current ground based observations Breger et al A&A 419, 695 FG Vir

8 Ubatuba Nov 20052nd CoRoT Brazil Current ground based observations Current ground based observations DFT (Daily Aliasing) DFT (Daily Aliasing) Frequencies estimations: Frequencies estimations: simultaneous n-fitting at step n simultaneous n-fitting at step n Frequency errors: Frequency errors: Rayleigh resolution (1/T) Rayleigh resolution (1/T) or or non-linear fitting non-linear fitting Amplitude and phase errors: Amplitude and phase errors: least square fitting at fixed frequencies least square fitting at fixed frequencies

9 Ubatuba Nov 20052nd CoRoT Brazil Schwanzerberg-Czerny 1991 MNRAS, 253, 198: Uncorrelated observations σ(F) = 6/π * (N/S) * (1/Nt) * (1/T) S/N Signal to Noise ratio S/N Signal to Noise ratio Nt Total number of observations Nt Total number of observations T Time base T Time base Correlated observations Correlated observations σ(F)= D * σ(F) σ(F)= D * σ(F) D Correlation length (post mortem) D Correlation length (post mortem)

10 Ubatuba Nov 20052nd CoRoT Brazil Present ground based observations Present ground based observations Amplitude and phases errors: Amplitude and phases errors: Least squares at fixed frequencies Least squares at fixed frequencies Best errors values for ground based : Best errors values for ground based : 0.05 mmags and 0.5 degrees mmags and 0.5 degrees. Main results for δ Scuti: Main results for δ Scuti: Amplitude and phase variations Amplitude and phase variations

11 Ubatuba Nov 20052nd CoRoT Brazil Breger, M. 2000, MNRAS 313, 129 Rodriguez et al. 1998, A&A 338, And Amplitude variations 4 CVn

12 Ubatuba Nov 20052nd CoRoT Brazil Breger, M. 2000, MNRAS 313, 129 Garrido & Rodriguez 1996 MNRAS 281, CVn

13 Ubatuba Nov 20052nd CoRoT Brazil Wavelets (Equally spaced data): Mexican hat Morlet

14 Ubatuba Nov 20052nd CoRoT Brazil Wavelets (Equally spaced data):

15 Ubatuba Nov 20052nd CoRoT Brazil Bispectra (Equally spaced data) non zero only when quadratic coupling exists !

16 Ubatuba Nov 20052nd CoRoT Brazil SOHO: bispectrum modulus.

17 Ubatuba Nov 20052nd CoRoT Brazil

18 Ubatuba Nov 20052nd CoRoT Brazil z Suárez et al. 2005, A&A Submitted

19 Ubatuba Nov 20052nd CoRoT Brazil Breger et al A&A 341, 151 Frequency differences FG Vir

20 Ubatuba November nd CoRoT Brazil One layer approximation One layer approximation Radiative equilibrium in the local atmosphere Radiative equilibrium in the local atmosphere Dupret et al A&A 398, 677 Moya et al A&A 414, 1081 Non-adiabatic models:

21 Ubatuba Nov 20052nd CoRoT Brazil Convection – pulsation interaction 3-D hydrodynamic simulations All motions are convective ones In particular the p-modes (present in the solution) Nordlund & Stein Perturbative approach Separation between convection and pulsation in the Fourier space of turbulence Convective motions: short wave-lengths Oscillations: long wave-lengths Gough´s theory Gabriel´s theory MLT

22 Ubatuba Nov 20052nd CoRoT Brazil Hydrodynamic equations Mean equations Convective fluctuations equations Equations of linear non-radial non-adiabatic oscillations Correlation terms Perturbation Convection – pulsation interaction: Gabriel´s theory Convective flux Reynolds stress Turbulent kinetic energy dissipation Perturbation of

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25 Ubatuba Nov 20052nd CoRoT Brazil p7p7 p1p1 1.4 M M M 0 2 M M 0 = = 0 δ Scuti Stars Red border δ Scuti Stars Red border Grigahcene et al A&A 434, 1055 Dupret et al A&A 414, L17 Dupret et al A&A 435, 927

26 Ubatuba Nov 20052nd CoRoT Brazil p7p7 p1p1 1.4 M 0 2 M M M M 0 = 1 - = 0 δ Scuti Stars Red border δ Scuti Stars Red border Grigahcene et al A&A 434, 1055 Dupret et al A&A 414, L17 Dupret et al A&A 435, 927

27 Ubatuba Nov 20052nd CoRoT Brazil p1p1 p7p7 p1p1 1.4 M M 0 2 M M M 0 = = 0 δ Scuti Stars Red border δ Scuti Stars Red border Grigahcene et al A&A 434, 1055 Dupret et al A&A 414, L17 Dupret et al A&A 435, 927

28 Ubatuba Nov 20052nd CoRoT Brazil p6p6 fBfB g7g7 fRfR 1.4 M 0 2 M M M M 0 = = 2 δ Scuti Stars Red border δ Scuti Stars Red border Grigahcene et al A&A 434, 1055 Dupret et al A&A 414, L17 Dupret et al A&A 435, 927

29 Ubatuba Nov 20052nd CoRoT Brazil γ Doradus stars g- and p-unstable modes γ Doradus stars g- and p-unstable modes 1.5 M 0 - l = 1 - a = 1.5 Grigahcene et al A&A 434, 1055 Dupret et al A&A 414, L17 Dupret et al A&A 435, 927

30 Ubatuba Nov 20052nd CoRoT Brazil γ Doradus stars Instability strip γ Doradus stars Instability strip Grigahcene et al A&A 434, 1055 Dupret et al A&A 414, L17 Dupret et al A&A 435, 927

31 Ubatuba Nov 20052nd CoRoT Brazil Moya et al A&A, 432, 189 Suarez et al A&A 443, 271 γ Doradus stars Frequency ratio method γ Doradus stars Frequency ratio method

32 Ubatuba Nov 20052nd CoRoT Brazil Moya et al A&A, 432, 189 Suarez et al A&A 443, 271 γ Doradus stars Frequency ratio method γ Doradus stars Frequency ratio method

33 Poretti et al A&A 406, 203 Poretti et al A. J. 129, 2461

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48 Ubatuba Nov 20052nd CoRoT Brazil CONCLUSIONS COROT data: Continuous data (no alias, techniques requiring equally spaced data, high Nyquist frequency for sismo data) Continuous data (no alias, techniques requiring equally spaced data, high Nyquist frequency for sismo data) Exploration of the high frequency region (Solar like?) Exploration of the high frequency region (Solar like?) Discovery of unique objects (δ Scuti + γ Dor + solar like?) Discovery of unique objects (δ Scuti + γ Dor + solar like?) Amplitude, phase (and frequency?) changes Amplitude, phase (and frequency?) changes Mode identification (frequency differences, linear combinations, colours, FRM) Mode identification (frequency differences, linear combinations, colours, FRM)


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