J/A+A/525/A23 Frequency analysis of HD 49434 (Mathias+, 2011)
The gamma Doradus CoRoT target HD 49434.
II. Frequency analysis of the CoRoT data.
Chapellier E., Rodriguez E., Auvergne M., Uytterhoeven K., Mathias P.,
Bouabid M.-P., Poretti E., Le Contel D., Martin-Ruiz S., Amado P.J.,
Garrido R., Hareter M., Rainer M., Eyer L., Paparo M., Diaz-Fraile D.,
Baglin A., Baudin F., Catala C., Michel E., Samadi R.
<Astron. Astrophys. 525, A23 (2011)>
=2011A&A...525A..23C 2011A&A...525A..23C
ADC_Keywords: Stars, variable ; Spectroscopy
Keywords: stars: variables: general - stars: individual: HD 49434 -
stars: oscillations - techniques: photometric
Abstract:
HD 49434 is a bright (V=5.75mag) and multiperiodic gamma Dor-type
pulsator that has been selected for the asteroseismic core programme
of the CoRoT satellite.
An extensive and detailed study has been carried out to investigate
the pulsational content of this object on the basis of the 136.9d
(331291 useful datapoints) time series collected by the CoRoT
satellite during the long-run LRa01 (October 2007-March 2008).
Description:
The frequency analysis was carried out using the recently available
software package SigSpec and Period04.
Objects:
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RA (2000) DE Designation(s)
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06 48 19.1 -01 19 08 HD 49434 = HR 2514
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 119 1686 List of peaks detected for HD49434 in the
frequency region 0.05-30c/d
table3.dat 39 481 List of combination frequencies identified in
the frequency list of HD49434 in the region
0.05-30c/d and range for validity of 0.005c/d
table6.dat 85 978 *List of peaks detected for Subset 1 of HD49434
table7.dat 85 896 *List of peaks detected for Subset 2 of HD49434
table8.dat 82 772 Frequency matching between Subset 1 (i) and the
Subset 2 (j) listed within a range of
|fre(i)-fre(j)|=0.005c/d
table9.dat 82 1468 Frequency matching between Subset 1 (i) and the
Subset 2 (j) listed within a range of
|fre(i)-fre(j)|=0.010c/d
table11.dat 82 1416 Frequency matching between Subset 1 (i) and the
Whole dataset (j) listed within a range of
|fre(i)-fre(j)|=0.005c/d
table12.dat 82 1319 Frequency matching between Subset 2 (i) and the
Whole dataset (j) listed within a range of
|fre(i)-fre(j)|=0.005c/d
table13.dat 82 2701 Frequency matching between Subset 1 (i) and the
Whole dataset (j) listed within a range of
|fre(i)-fre(j)|=0.010c/d
table14.dat 82 2430 Frequency matching between Subset 2 (i) and the
Whole dataset (j) listed within a range of
|fre(i)-fre(j)|=0.010c/d
table16.dat 33 98 Frequencies which are in Subset 1 but not in the
Whole dataset (within a range of
|fre(i)-fre(j)|=0.005c/d)
table17.dat 33 70 Frequencies which are in Subset 2 but not in the
Whole dataset (within a range of
|fre(i)-fre(j)|=0.005c/d)
table18.dat 33 17 Frequencies which are in Subset 1 but not in the
Whole dataset (within a range of
|fre(i)-fre(j)|=0.010c/d)
table19.dat 33 19 Frequencies which are in Subset 2 but not in the
Whole dataset (within a range of
|fre(i)-fre(j)|=0.010c/d)
table21.dat 52 1015 This table is similar to Table 2 (list of 1686
peaks for HD 49434), but the secondary peaks,
closer than the frequency resolution
1/DT=0.0073c/d, have been removed from the list
table22.dat 30 840 List of peaks retained by phase constancy method
table23.dat 84 281 List of peaks retained by matching frequency method
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Note on table6.dat: The analysis was performed on Subset1, consisting of a
subset of the CoRoT lightcurve of HD49434, between CoRoT days 0.0 to 70.0.
Note on table7.dat: The analysis was performed on Subset2, consisting of a
subset of the CoRoT lightcurve of HD49434, between CoRoT days 70.0 to 136.9.
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See also:
B/corot : CoRoT observation log (CoRoT, 2009)
J/ApJ/598/597 : Frequency analysis of fundamental-mode RR Lyrae (Alcock+, 2003)
J/A+A/506/111 : Frequency analysis of HD 180642 (V1449 Aql) (Degroote+, 2009)
J/A+A/506/471 : Frequency analysis of CoRoT B stars (Degroote+, 2009)
Byte-by-byte Description of file: table[267].dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- i Number of the peak, in the same order as it
was detected (G1)
6- 16 F11.8 d-1 Freq Frequency
18- 23 F6.4 mmag Ampl Amplitude
25- 33 F9.6 rad Phase Phase
35- 43 F9.3 --- sig Spectral significance as defined by
Reegen (2007A&A...467.1353R 2007A&A...467.1353R) (1)
45- 52 F8.3 --- S/N Signal-to-noise ratio (2)
54- 58 F5.3 mmag rms rms for frequency "i" (sigma of the residuals
before extracting the peak "i")
60- 69 F10.8 d-1 e_Freq Formal error bars on frequency (3)
71- 76 F6.4 mmag e_Ampl Formal error bars on Amplitude (3)
78- 85 F8.6 rad e_Phase Formal error bars on Phase (3)
87-119 A33 --- Com Comments (4)
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Note (1): We have used the program package SigSpec (Reegen 2007A&A...467.1353R 2007A&A...467.1353R).
We performed iterations until the limit of sig=20.0 for spectral
significance (not sig=5.0 as used as default in SigSpec) because the
corresponding S/N value in our data (as determined later using
Period04 on the residuals provided by SigSpec) were much lower than
4.0. After this, we have used Period04 to determine the corresponding
noise level and the S/N value.
Note (2): Signal-to-noise ratio, calculated using Period04 (Lenz & Breger,
2005, CoAst 146, 5) on the residuals provided by SigSpec.
Each S/N value was calculated on a box of width=5 c/d centred on the
corresponding peak, as is usual (e.g. Breger, Stich, Garrido, et al.,
1993A&A...271..482B 1993A&A...271..482B).
Note (3): Determined using the formulae of Montgomery & O'Donoghue
(1999, DSSN 13, 28).
Note (4): We list the possible identification of harmonics or combinations
between the main peaks within an error bar of "±0.005c/d". For this
study only the first twelve main peaks of the list (f1 to f12), the
first five harmonics of f1 and f4, and combinations considering the
first, second and third orders have been taken into account.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Comb Combination name (1)
17- 18 I2 --- Ncomb Combination number
20- 26 F7.4 d-1 Freqcomb Frequency of the combination (2)
28- 31 I4 --- i Identified peak: number of the peak in the
list of detected peaks for this dataset,
(this is the order of detection)
33- 39 F7.4 d-1 Freq Identified peak: frequency of the peak
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Note (1): For this study only the first twelve main peaks of the list (f1
to f12), the first five harmonics of f1 and f4, and combinations
considering the first, second and third orders have been taken into
account.
Note (2): All frequencies that can be identified with a combination
frequency within an errorbar of 0.005c/d have been considered as
valid. We only considered frequencies in the range 0.05-30c/d.
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Byte-by-byte Description of file: table[89].dat table1[1234].dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- i Number of the peak in the first dataset
6- 12 F7.4 d-1 Freqi Frequency in the first dataset
14- 18 F5.3 mmag Ampli Amplitude in the first dataset
20- 27 F8.3 --- sigi Spectral significance as defined by
Reegen (2007A&A...467.1353R 2007A&A...467.1353R) in the first dataset
29- 35 F7.3 --- S/Ni Signal-to-noise ratio in the first dataset
38- 41 I4 --- j Number of the peak in the second dataset
43- 49 F7.4 d-1 Freqj Frequency in the second dataset
51- 55 F5.3 mmag Amplj Amplitude in the second dataset
57- 65 F9.3 --- sigj Spectral significance as defined by
Reegen (2007A&A...467.1353R 2007A&A...467.1353R) in second dataset
67- 74 F8.3 --- S/Nj Signal-to-noise ratio in the Subset second dataset
76- 82 A7 --- Com Interpretation (1)
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Note (1): Our interpretation concerning if two peaks (one from the first
list and another from the second list) are the "same" peak or not,
based on the following limits:
* For table8, table11, table12
a) The two peaks (i and j) are located within a frequency range lower
than 0.005c/d, that is, |fre(i)-fre(j)|≤0.005c/d, and
b) The difference in order is lower than 50, that is, |i-j|≤50
* For table9, table13, table14
a) The two peaks (i and j) are located within a frequency range lower
than 0.01c/d, that is, |fre(i)-fre(j)|≤0.01 c/d, and
b) The difference in order is lower than 50, that is, |i-j|≤50
or
c) If the difference in order is between 50 to 100, that is,
"50≤|i-j|≤100", then:
c1) if the difference in amplitude in lower than 20%, then the
frequency matching is "real"
c2) if the difference in amplitude is between 20% to 50%, then the
frequency matching is "casual?"
c3) if the difference in amplitude is larger than 50%, then the
frequency matching is "casual"
or
c) If the difference in order is between 50 to 100, that is,
"50≤|i-j|≤100", then:
c1) if the difference in amplitude in lower than 20%, then the
frequency matching is "real"
c2) if the difference in amplitude is between 20% to 50%, then the
frequency matching is "casual?"
c3) if the difference in amplitude is larger than 50%, then the
frequency matching is "casual"
or
d) If the difference in order is larger than 100, that is,
|i-j|≥100, then
d1) if the difference in amplitude is lower than 50%, then the
frequency matching is "casual?"
d2) if the difference in amplitude is larger than 50%, then the
frequency matching is "casual"
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Byte-by-byte Description of file: table1[6789].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- i Number of the peak, in the same order as it
was detected
6- 12 F7.4 d-1 Freq Frequency
14- 18 F5.3 mmag Ampl Amplitude
20- 26 F7.3 --- sig Spectral significance as defined by
Reegen (2007A&A...467.1353R 2007A&A...467.1353R)
28- 33 F6.3 --- S/N Signal-to-noise ratio
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table21.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- i Number of the peak, in the same order as it
was detected (G1)
6- 16 F11.8 d-1 Freq Frequency
18- 23 F6.4 mmag Ampl Amplitude
25- 33 F9.6 rad Phase Phase
35- 43 F9.3 --- sig Spectral significance as defined by
Reegen (2007A&A...467.1353R 2007A&A...467.1353R)
45- 52 F8.3 --- S/N Signal-to-noise ratio (2)
--------------------------------------------------------------------------------
Note (2): Signal-to-noise ratio, calculated using Period04 (Lenz & Breger,
2005, CoAst 146, 5) on the residuals provided by SigSpec.
Each S/N value was calculated on a box of width=5 c/d centred on the
corresponding peak, as is usual (e.g. Breger, Stich, Garrido, et al.,
1993A&A...271..482B 1993A&A...271..482B).
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Byte-by-byte Description of file: table22.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- i Number of the peak, in the same order as it
was detected
6- 16 F11.8 d-1 Freq Frequency
18- 23 F6.4 mmag Ampl Amplitude
25- 30 F6.4 --- deltaPhi Absolute value of the phase difference between
a sine-fit performed on S1 and S2 using the
same frequency f in unit 1/f
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Byte-by-byte Description of file: table23.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- i Number of the peak in the Subset 1
6- 12 F7.4 d-1 Freqi Frequency in the Subset 1
14- 18 F5.3 mmag Ampli Amplitude in the Subset 1
20- 27 F8.3 --- sigi Spectral significance as defined by
Reegen (2007A&A...467.1353R 2007A&A...467.1353R) in the Subset 1
29- 35 F7.3 --- S/Ni Signal-to-noise ratio in the Subset 1
38- 41 I4 --- j Number of the peak in the Subset 2
43- 49 F7.4 d-1 Freqj Frequency in the Subset 2
51- 55 F5.3 mmag Amplj Amplitude in the Subset 2
57- 65 F9.3 --- sigj Spectral significance as defined by
Reegen (2007A&A...467.1353R 2007A&A...467.1353R) in the Subset 2
67- 74 F8.3 --- S/Nj Signal-to-noise ratio in the Subset 2
76- 82 A7 --- Com Interpretation (1)
84 A1 --- Peak [Y/N] Peak retains (Y) or not (N) using the
phase constancy method
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Note (1): Our interpretation concerning if two peaks (one from the first
list and another from the second list) are the "same" peak or not.
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Global notes:
Note (G1): Possible interactions with the satellite orbital frequency
(assumed as fs=13.972 c/d, fs in the table) has also been studied
for the first four main peaks (f1 to fyyyyyy4) and four first
harmonics of fs (fs to 4fs). Please note that our range of interest
in this table is only from 0 to 30 c/d.
We have also studied remaining peaks (residuals) corresponding to the
sidelobes of 1 c/d alias frequencies around fs and its harmonics.
Moreover, we have also studied the possible interactions between
"peaks remaining in the very low frequency domain (lower than
0.05c/d)" with fs (and 1c/d alias and harmonics). The main peak in
this region is fl=0.01104c/d with Amplitude=0.257mmag. As shown in
this table, some peaks at very low amplitudes seem to originate from
these interactions.
In summary, 663 possible combinations have been considered. A total
of 481 identifications have been detected, but only 312 of them are
independent identifications. Moreover, a number of these probably are
only "casual coincidences".
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Acknowledgements:
Philippe Mathias, pmathias(at)ast.obs-mip.fr
References:
Uytterhoeven et al., Paper I 2008A&A...489.1213U 2008A&A...489.1213U
(End) Patricia Vannier [CDS] 26-Jul-2010