Physical insights on fractal analysis applied to light curves $delta$ Scuti stars. (arXiv:1901.10476v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Franciscis_S/0/1/0/all/0/1">S. de Franciscis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pascual_Granado_J/0/1/0/all/0/1">J. Pascual-Granado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Suarez_J/0/1/0/all/0/1">J. C. Suárez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hernandez_A/0/1/0/all/0/1">A. García Hernández</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Garrido_R/0/1/0/all/0/1">R. Garrido</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lares_Martiz_M/0/1/0/all/0/1">M. Lares-Martiz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rodon_J/0/1/0/all/0/1">J. R. Rodón</a>
Fractal fingerprints have been found recently in the light curves of several
{delta} Scuti stars observed by CoRoT satellite. This sole fact might pose a
problem for the detection of pulsation frequencies using classical
pre-whitening techniques, but it is also a potentially rich source for
information about physical mechanisms associated to stellar variability.
Assuming that a light curve is composed by a superposition of oscillation modes
with a fractal background noise, in this work we applied the Coarse Graining
Spectral Analysis (CGSA), an FFT based algorithm, which can discriminate in a
time series the stochastic fractal power spectra from the harmonic one. We have
found that the fractal background component is determining the frequency
content extracted using classical pre-whitening techniques in the light curves
of {delta} Scuti stars. This might be crucial to understand the amount of
frequencies excited in these kind of pulsating stars. Additionally, CGSA
resulted to be relevant in order to extract the oscillation modes, this points
to a new criterion to stop the pre-whitening cascade based on the percentage of
fractal component in the residuals.
Fractal fingerprints have been found recently in the light curves of several
{delta} Scuti stars observed by CoRoT satellite. This sole fact might pose a
problem for the detection of pulsation frequencies using classical
pre-whitening techniques, but it is also a potentially rich source for
information about physical mechanisms associated to stellar variability.
Assuming that a light curve is composed by a superposition of oscillation modes
with a fractal background noise, in this work we applied the Coarse Graining
Spectral Analysis (CGSA), an FFT based algorithm, which can discriminate in a
time series the stochastic fractal power spectra from the harmonic one. We have
found that the fractal background component is determining the frequency
content extracted using classical pre-whitening techniques in the light curves
of {delta} Scuti stars. This might be crucial to understand the amount of
frequencies excited in these kind of pulsating stars. Additionally, CGSA
resulted to be relevant in order to extract the oscillation modes, this points
to a new criterion to stop the pre-whitening cascade based on the percentage of
fractal component in the residuals.
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