Multi-resolution wavelet analysis of high time resolution millimeter wavelength observations of solar bursts

By means of the wavelet representation of multi-resolution analysis, we study millimeter wavelength (mm-w) radio solar bursts obtained at 48 GHz with high time resolution (≤8 ms); observed at Itapetinga (Brazil). The multi-resolution analysis decomposes the signal locally both in time and in frequen...

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Publicado: 2001
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v366_n1_p317_GimenezDeCastro
http://hdl.handle.net/20.500.12110/paper_00046361_v366_n1_p317_GimenezDeCastro
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spelling paper:paper_00046361_v366_n1_p317_GimenezDeCastro2023-06-08T14:27:25Z Multi-resolution wavelet analysis of high time resolution millimeter wavelength observations of solar bursts Methods: data analysis Sun: flares Sun: radio radiation By means of the wavelet representation of multi-resolution analysis, we study millimeter wavelength (mm-w) radio solar bursts obtained at 48 GHz with high time resolution (≤8 ms); observed at Itapetinga (Brazil). The multi-resolution analysis decomposes the signal locally both in time and in frequency, allowing us to identify the different temporal structures which underlie the flux density time series and the transient phenomena characteristic of solar bursts. The analysis was applied to the flux time profile of four solar bursts observed at a mm-w, studying separately the pre-flare, impulsive and post-flare phases when possible. We find that a wide range of time scales contributes to the radio flux. The minimum time scale found for the impulsive phase is 32 ms, after which the noise dominates the emission; the maximum is 8 s. Pre- and post-flare phases have a minimum time scale of 256 ms and a maximum between 1 to 8 s. Multi-resolution "spectral indexes", which are a measure of the self-similar behaviour of the signal, are in some cases bigger for the impulsive phase than for the pre- and post-flare phases. We find that as the flux becomes higher the contribution from shorter time scales is enhanced. 2001 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v366_n1_p317_GimenezDeCastro http://hdl.handle.net/20.500.12110/paper_00046361_v366_n1_p317_GimenezDeCastro
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Methods: data analysis
Sun: flares
Sun: radio radiation
spellingShingle Methods: data analysis
Sun: flares
Sun: radio radiation
Multi-resolution wavelet analysis of high time resolution millimeter wavelength observations of solar bursts
topic_facet Methods: data analysis
Sun: flares
Sun: radio radiation
description By means of the wavelet representation of multi-resolution analysis, we study millimeter wavelength (mm-w) radio solar bursts obtained at 48 GHz with high time resolution (≤8 ms); observed at Itapetinga (Brazil). The multi-resolution analysis decomposes the signal locally both in time and in frequency, allowing us to identify the different temporal structures which underlie the flux density time series and the transient phenomena characteristic of solar bursts. The analysis was applied to the flux time profile of four solar bursts observed at a mm-w, studying separately the pre-flare, impulsive and post-flare phases when possible. We find that a wide range of time scales contributes to the radio flux. The minimum time scale found for the impulsive phase is 32 ms, after which the noise dominates the emission; the maximum is 8 s. Pre- and post-flare phases have a minimum time scale of 256 ms and a maximum between 1 to 8 s. Multi-resolution "spectral indexes", which are a measure of the self-similar behaviour of the signal, are in some cases bigger for the impulsive phase than for the pre- and post-flare phases. We find that as the flux becomes higher the contribution from shorter time scales is enhanced.
title Multi-resolution wavelet analysis of high time resolution millimeter wavelength observations of solar bursts
title_short Multi-resolution wavelet analysis of high time resolution millimeter wavelength observations of solar bursts
title_full Multi-resolution wavelet analysis of high time resolution millimeter wavelength observations of solar bursts
title_fullStr Multi-resolution wavelet analysis of high time resolution millimeter wavelength observations of solar bursts
title_full_unstemmed Multi-resolution wavelet analysis of high time resolution millimeter wavelength observations of solar bursts
title_sort multi-resolution wavelet analysis of high time resolution millimeter wavelength observations of solar bursts
publishDate 2001
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v366_n1_p317_GimenezDeCastro
http://hdl.handle.net/20.500.12110/paper_00046361_v366_n1_p317_GimenezDeCastro
_version_ 1768544470409674752