Post on 19-Dec-2015
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
δδ Scuti and Scuti and γγ Dor stars in Dor stars in
COROTCOROT
Rafael GarridoRafael Garrido
IAA, Granada (Spain)IAA, Granada (Spain)
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Current ground based observationsCurrent ground based observations
δδ Scuti:Scuti: 0.3 – 3 hours (p- and mixed modes) 0.3 – 3 hours (p- and mixed modes)
γγ Doradus:Doradus: 0.4 – several days (g-modes) 0.4 – several days (g-modes)
both regimes? (Dupret et al. 2004 A&A 414, L17)both regimes? (Dupret et al. 2004 A&A 414, L17)
and and Solar likeSolar like oscillations? (Samadi et al. 2002 A&A 395, 563) oscillations? (Samadi et al. 2002 A&A 395, 563)
Mode identification:Mode identification:
Frequency differences: Sismo & ExoFrequency differences: Sismo & Exo
Frequency combinations: Sismo & ExoFrequency combinations: Sismo & Exo
Colour information: ExoColour information: Exo
Frequency Ratio Method (Frequency Ratio Method (γγ Dor)Dor) : Sismo & Exo : Sismo & Exo
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FG VirCurrent ground based observationsCurrent ground based observations
Breger et al. 2004 A&A 419, 695
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Breger et al. 2004 A&A 419, 695
FG VirCurrent ground based observationsCurrent ground based observations
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Current ground based observationsCurrent ground based observations
Breger et al. 2004 A&A 419, 695
FG Vir
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Breger et al. 2004 A&A 419, 695
FG VirCurrent ground based observationsCurrent ground based observations
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Current ground based observationsCurrent ground based observations
Breger et al. 2004 A&A 419, 695
FG Vir
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Current ground based observationsCurrent ground based observations
DFT (Daily Aliasing)DFT (Daily Aliasing)
Frequencies estimations:Frequencies estimations:
simultaneous n-fitting at step nsimultaneous n-fitting at step n
Frequency errors:Frequency errors:
Rayleigh resolution (1/T)Rayleigh resolution (1/T)
oror
non-linear fitting non-linear fitting
Amplitude and phase errors:Amplitude and phase errors:
least square fitting at fixed frequenciesleast square fitting at fixed frequencies
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Schwanzerberg-Czerny 1991 MNRAS, 253, 198:
Uncorrelated observationsUncorrelated observations
σσ(F) = √6/(F) = √6/ππ * (N/S) * (1/√Nt) * (1/T) * (N/S) * (1/√Nt) * (1/T)
S/N Signal to Noise ratioS/N Signal to Noise ratio Nt Total number of observationsNt Total number of observations T Time baseT Time base
Correlated observations Correlated observations
σσ(F)= √D * (F)= √D * σσ(F) (F) D Correlation length (“post mortem”)D Correlation length (“post mortem”)
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Present ground based observationsPresent ground based observations
Amplitude and phases errors:Amplitude and phases errors:
Least squares at fixed frequenciesLeast squares at fixed frequencies
Best errors values for ground based : Best errors values for ground based :
0.05 mmags and 0.5 degrees.0.05 mmags and 0.5 degrees.
Main results for Main results for δδ Scuti Scuti::
Amplitude and phase variationsAmplitude and phase variations
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Breger, M. 2000, MNRAS 313, 129Rodriguez et al. 1998, A&A 338, 905 28 And
Amplitude variationsAmplitude variations
4 CVn
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Breger, M. 2000, MNRAS 313, 129Breger, M. 2000, MNRAS 313, 129
Garrido & Rodriguez 1996 MNRAS 281, 696Garrido & Rodriguez 1996 MNRAS 281, 696
4 CVn
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Wavelets (Equally spaced Wavelets (Equally spaced data):data):
Mexican hatMexican hat MorletMorlet
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Wavelets (Equally spaced Wavelets (Equally spaced data):data):
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Bispectra (Equally spaced data)Bispectra (Equally spaced data)
non zero only when quadratic coupling exists !
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
SOHO: bispectrum modulus.SOHO: bispectrum modulus.
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Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8 z
Suárez et al. 2005, A&A SubmittedSuárez et al. 2005, A&A Submitted
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Breger et al. 1999 A&A 341, 151Breger et al. 1999 A&A 341, 151
Frequency differencesFrequency differences FG Vir
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p7
p1
1.4 M0
1.6 M0
1.8 M0
2 M0
2.2 M0
= 0.5 - = 0
δδ Scuti Stars Scuti Stars Red borderRed border
Grigahcene et al. 2005 A&A 434, 1055
Dupret et al. 2004 A&A 414, L17
Dupret et al. 2005 A&A 435, 927
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
p7
p1
1.4 M0
2 M0
1.8 M0
1.6 M0
2.2 M0
= 1 - = 0
δδ Scuti Stars Scuti Stars Red borderRed border
Grigahcene et al. 2005 A&A 434, 1055
Dupret et al. 2004 A&A 414, L17
Dupret et al. 2005 A&A 435, 927
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
p1p7
p1
1.4 M0
1.8 M0
2 M0
2.2 M0
1.6 M0
= 1.5 - = 0
δδ Scuti Stars Scuti Stars Red borderRed border
Grigahcene et al. 2005 A&A 434, 1055
Dupret et al. 2004 A&A 414, L17
Dupret et al. 2005 A&A 435, 927
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
p6
fB
g7
fR
1.4 M0
2 M0
2.2 M0
1.8 M0
1.6 M0
= 1.5 - = 2
δδ Scuti Stars Scuti Stars Red borderRed border
Grigahcene et al. 2005 A&A 434, 1055
Dupret et al. 2004 A&A 414, L17
Dupret et al. 2005 A&A 435, 927
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
γγ Doradus stars Doradus starsg- and p-unstable modesg- and p-unstable modes
1.5 M0 - l = 1 - a = 1.5
Grigahcene et al. 2005 A&A 434, 1055
Dupret et al. 2004 A&A 414, L17
Dupret et al. 2005 A&A 435, 927
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
γγ Doradus stars Doradus stars Instability stripInstability strip
Grigahcene et al. 2005 A&A 434, 1055
Dupret et al. 2004 A&A 414, L17
Dupret et al. 2005 A&A 435, 927
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Moya et al. 2005 A&A, 432, 189Suarez et al. 2005 A&A submitted
γγ Doradus stars Doradus stars Frequency ratio methodFrequency ratio method
Toulouse May 2005Toulouse May 2005 Corot-Week 8 Corot-Week 8
Moya et al. 2005 A&A, 432, 189Suarez et al. 2005 A&A submitted
γγ Doradus stars Doradus stars Frequency ratio methodFrequency ratio method
Poretti et al. 2003 A&A 406, 203Poretti et al. 2005 A. J. 129, 2461
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CONCLUSIONSCONCLUSIONS
COROT data:COROT data:
• Continuous data (no alias, techniques requiring Continuous data (no alias, techniques requiring
equally spaced data, high Nyquist frequency for equally spaced data, high Nyquist frequency for
sismo data)sismo data)
• Exploration of the high frequency region (Solar Exploration of the high frequency region (Solar
like?)like?)
• Discovery of unique objects (Discovery of unique objects (δδ Scuti + Scuti + γγ Dor + Dor +
solar like?)solar like?)
• Amplitude, phase (and frequency?) changesAmplitude, phase (and frequency?) changes
• Mode identification (frequency differences, Mode identification (frequency differences,
linear combinations, colours, FRM)linear combinations, colours, FRM)