Space- and ground-based asteroseismology · Introduction Asteroseismology Asteroseismology Why? LC}...

Space- and ground-based

asteroseismology

S. Barcelo Forteza, D. Barrado, A. Moya, S. Martın-Ruiz,V. Casanova, A. Garcıa Hernandez.

21 February 2019

Introduction Asteroseismology

Asteroseismology

Why?

LCLV → PSD → ν, A, Γi → νmax → Teff,⋆ → Teff,P

Observed from

1 Ground: CARMENES, SONG

2 Space: CoRoT, Kepler, TESS

Observed and estimated data of CID 546 light curve.

S. Barcelo Forteza CARMENES + EXONET 21 February 2019 1 / 12


Asteroseismology

Why?


i

How to calculate:

1 Gaussian fit

2 Kallinger et al. (2010):

νmax =∑

Aiνi∑Ai

PSD of the red giant KIC 5701829.



Asteroseismology

Why?


i

Scaling relations

Kjeldsen & Bedding (1995):

νmax ∝ MR−2T−0.5eff

(

Teff,P

Teff,⋆

)2

= R⋆

2a

PSD of the red giant KIC 5701829.


Introduction δ Scuti stars

δ Scuti stars

Characteristics:

κ-mechanism (Chevalier 1971; Xiong et al. 2016)

M ∈ [1.5, 2.5] M⊙

Teff ∈ [6000, 9000] K

Ω . ΩC

ν ∈ [60, 930] µHz

Scaling relation?

1 Dziembowski (1997):Teff ∝ νi


νmax =∑

Aiνi∑Ai

Pulsators in the HR diagram (Barcelo Forteza et al., submitted).



δ Scuti stars

Characteristics:


M ∈ [1.5, 2.5] M⊙

Teff ∈ [6000, 9000] K

Ω . ΩC

ν ∈ [60, 930] µHz

Scaling relation?

1 Dziembowski (1997):Teff ∝ νi


νmax =∑

Aiνi∑Ai

Excited modes of a δ Scuti model from Dziembowski (1997).



δ Scuti stars

Characteristics:


M ∈ [1.5, 2.5] M⊙

Teff ∈ [6000, 9000] K

Ω . ΩC

ν ∈ [60, 930] µHz

Scaling relation?

Teff ∝ νmax

Excited modes of a δ Scuti model from Dziembowski (1997).


Introduction Gravity-darkening effect

Gravity-darkening effect

Rotation

geff (i) ≈ g − R(i)Ω2 sin2i

Teff (i) ∝ gβ/4eff

(i) → β ≈ 1 (von Zeipel 1924)

δTeff (i) ≡(

Teff(i)− Teff

)

/Teff




Rotation



(i) → β ≈ 1 (von Zeipel 1924)

δTeff (i) ≡(

Teff(i)− Teff

)

/Teff

Ω/ΩC = 0

|δTeff (i)| = 0 %




Rotation



(i) → β ≈ 1 (von Zeipel 1924)

δTeff (i) ≡(

Teff(i)− Teff

)

/Teff

Ω/ΩC = 0

|δTeff (i)| = 0 %

Ω/ΩC = 0.7

|δTeff (i)| . 5.9 %




Rotation



(i) → β ≈ 1 (von Zeipel 1924)

δTeff (i) ≡(

Teff(i)− Teff

)

/Teff

Ω/ΩC = 0

|δTeff (i)| = 0 %

Ω/ΩC = 0.7

|δTeff (i)| . 5.9 %

Ω/ΩC = 1

|δTeff (i)| . 21.5 %




i ≈ 90

Ω/ΩC = 0

δTeff (i) = 0 %

Ω/ΩC = 0.7

δTeff (i) ≈ −3.3 %

Ω/ΩC = 1

δTeff (i) ≈ −21.5 %




i ≈ 0

Ω/ΩC = 0

δTeff (i) = 0 %

Ω/ΩC = 0.7

δTeff (i) ≈ 5.9 %

Ω/ΩC = 1

δTeff (i) ≈ 14.5 %




i ≈ 55

Ω/ΩC = 0

δTeff (i) = 0 %

Ω/ΩC = 0.7

δTeff (i) ≈ 0 %

Ω/ΩC = 1

δTeff (i) ≈ 0 %


Introduction Teff − νmax diagram

Teff − νmax diagram

Barcelo Forteza et al. (2018)

Teff = Teff(1 + δTeff(i))

1 νmax → Teff

2 δTeff(i) → Ω

ΩK, i

Predicted temperatures of over 5000 δ Scuti star models with ∀ νmax,Ω

ΩK, i including the Kepler ETeff ≈ 250 K


Data & Methods Data sources

Data sources

νmax,Teff

νmax → δSBF pipeline

Barcelo Forteza et al. (2015)

Teff → CATALOGUES

Brown et al. (2011)

Debosscher et al. (2009)

Measured νmax,Teff values of over a thousand δ Scuti stars.


Results Linear fit

Method 1: Linear fit

Teff ≈ a · νmax + b

a (K/µHz) 3.56 ± 0.23 σ (%) 6.52b (K) 6840 ± 50 Nin (%) 99R 0.954 Nout (%) 1


Results Linear fit

Method 1: Linear fit


a (K/µHz) 3.56 ± 0.23 σ (%) 1.08b (K) 6840 ± 50 Nin (%) 98R 0.954 Nout (%) 2


Results Known δ Scuti stars

Method 2: Known δ Scuti stars

Teff ,Ω

Ωk, i → Teff


a (K/µHz) 2.5 ± 0.5

b (K) 7090 ± 120∣

∣

∣

Teff−Teff,M

Teff,M

∣

∣

∣. ETeff

Teff

R 0.882


Conclusions & Future Work

Conclusions

We suggest a new scaling relation Teff − νmax for δSct

- non dependent of Ω

Ωk, i

- find Teff,P and H.Z.

Future work

Improve Teff − νmax with more data

Improve Teff − νmax with known δ Scuti stars

6= between photometric and spectroscopic data

TESS, CHEOPS

CARMENES

SONG


Acknowledgements

Thanks for your attention!

Acknowledgements

J.A. Caballero, E. Solano, C. Rodrıguez-Lopez


Acknowledgements

Barcelo Forteza, S., Michel, E., Roca Cortes, T., & Garcıa, R. A.2015, A&A, 579, A133

Barcelo Forteza, S., Roca Cortes, T., & Garcıa, R. A. 2018, A&A,614, A46

Brown, T. M., Latham, D. W., Everett, M. E., & Esquerdo, G. A.2011, AJ, 142, 112

Chevalier, C. 1971, A&A, 14, 24

Debosscher, J., Sarro, L. M., Lopez, M., et al. 2009, A&A, 506, 519

Dziembowski, W. 1997, in IAU Symposium, Vol. 181, Sounding Solarand Stellar Interiors, ed. J. Provost & F.-X. Schmider, 317

Kallinger, T., Mosser, B., Hekker, S., et al. 2010, A&A, 522, A1

Kjeldsen, H. & Bedding, T. R. 1995, A&A, 293, 87

von Zeipel, H. 1924, MNRAS, 84, 684

Xiong, D. R., Deng, L., Zhang, C., & Wang, K. 2016, MNRAS, 457,3163


Space- and ground-based asteroseismology · Introduction Asteroseismology Asteroseismology Why? LC}...

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