Analysis and modelling of the δ- Scuti stars HD174966 (ID7528) & HD174936 (ID7613)

1. Analysis and modelling of theδ-Scutistars HD174966 (ID7528) & HD174936 (ID7613) Antonio García Hernández; Moya, A.; Suárez, J.C.; Garrido, R. et al. (Instituto de Astrofísica de Andalucía, CSIC, Spain) CoRoT Symposium, February 2009

2. INTRODUCTION • Frequencyanalysis (Garrido et al. poster) • Main objetive: physicalcharacterisationstars: • HighqualityCoRoT data • Largenumber of frequencies CoRoT Symposium, February 2009

3. INTRODUCTION • Tools: • CESAM2k (Morel): equilibriummodels • GraCo (non-adiabaticeffects). Moya, A. & Garrido ,R. (2008,Ap&SS.316-129M) • FILOU (rotationaleffectssecondorder). Suárez, J.-C. & Goupil, M.J. (2008,Ap&SS.316-155S) CoRoT Symposium, February 2009

4. METHODOLOGY • Global parametersTeff, logg, Z ->uncertainty box in the HR diagram • Equilibriummodelscharacteristics: • CESAM2k code • 4000 points (ESTA recommendation) • αMLT= 0.5 • Diffusion (Michaud-Proffitformalismwithradiativediffusion) • Kurucz and Eddingtonatmospheremodels CoRoT Symposium, February 2009

5. METHODOLOGY • Calculate Fourier Transform ->large/smallseparation -> mean density, mass, age • Calculatefrequencies • Calculate non-adiabatic observables ->unstabilityrange (growthrate) • Calculatesecondorderrotationaleffects ->rotationalsplitting • Use of multi-colourphotometry and spectroscopy (LPV) CoRoT Symposium, February 2009

6. METHODOLOGY • Calculate Fourier Transform ->large/smallseparation -> mean density, mass, age • Calculatefrequencies • Calculate non-adiabatic observables ->unstabilityrange (growthrate) • Calculatesecondorderrotationaleffects ->rotationalsplitting • Use of multi-colourphotometry and spectroscopy (LPV) CoRoTSymposium, February 2009

7. METHODOLOGY • Calculate Fourier Transform ->large/smallseparation -> mean density, mass, age • Calculatefrequencies • Calculate non-adiabatic observables ->unstabilityrange (growthrate) • Calculatesecondorderrotationaleffects ->rotationalsplitting • Use ofmulti-colourphotometry and spectroscopy (LPV) CoRoT Symposium, February 2009

8. RESULTS • HD174966 (ID7528): • δ-Scuti (mainsequence) • Teff = 7637±200 K • logg = 4.03±0.2 • [Fe/H] = -0.11±0.2 • HD174936 (ID7613): • δ-scuti (mainsequence) • Teff = 8000±200 K • logg = 4.08±0.2 • [Fe/H] = -0.32±0.2 CoRoT Symposium, February 2009

9. RESULTS ID7613 ID7528 CoRoT Symposium, February 2009

10. CoRoT Symposium, February 2009

11. Rejectedmodel Newmodel CoRoT Symposium, February 2009

12. CoRoT Symposium, February 2009

13. CONCLUSIONS&FUTURE WORK • Usefulness of largenumber of frequencies: • Largeseparation • Growthrate • Disentanglerotationalsplitting and smallseparation • Colours • Spectroscopy (LPV) CoRoT Symposium, February 2009