Tendências espectrais de explosões solares em frequências Sub-THz
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Tipo
Tese
Data de publicação
2017-06-22
Periódico
Citações (Scopus)
Autores
Fernandes, Luís Olavo de Toledo
Orientador
Raulin, Jean Pierre
Título da Revista
ISSN da Revista
Título de Volume
Membros da banca
Correia, Emilia
Cassiano, Marta Maria
Selhorst, Caius Lucius
Fernandes, Francisco Carlos Rocha
Cassiano, Marta Maria
Selhorst, Caius Lucius
Fernandes, Francisco Carlos Rocha
Programa
Ciências e Aplicações Geoespaciais
Resumo
Previous sub-THz studies were derived from single event observations. Spectral trends for
a larger collection of sub-THz bursts have been analyzed for the first time. It consists of
a set of 16 moderate to small impulsive solar radio bursts observed at 0.2 and 0.4 THz
by the Solar Submillimeter-wave Telescope (SST) between 2012 and 2014 at El Leoncito,
in the Argentinean Andes.The peak burst spectra included data from new solar patrol
radio telescopes (45 and 90 GHz),and were complemented with microwave data obtained
by the RSTN, when available. We evaluate critically errors and uncertainties in sub-
THz flux estimates caused by calibration techniques and the corrections for atmospheric
transmission, and introduce a new method to obtain uniform flux scale criterion for all
16 events. The sub-THz bursts were searched during reported GOES soft x-ray events of
class C or larger, during periods of the SST observations. Seven out of 16 events exhibit
spectral maxima in the range 5-40 GHz with fluxes decaying at sub-THz frequencies (3
of them associated to GOES class X, and 4 to class M). Nine out of 16 events exhibited
the sub-THz spectral component. From these, 5 events exhibited the sub-THz emission
fluxes increasing with frequency separated from the microwave spectral component (2
classified as X and 3 as M) and 4 events have been detected at sub-THz frequencies only
(3 classified as M and 1 as C). The results suggest that the THz component might be
always present, with the minimum turn-over frequency increasing as a function of the
energy of the emitting electrons. In view of the peculiar nature of many sub-THz bursts
events, their better understanding requires further investigations of bursts examined on
the standpoint of SST observations alone.
Descrição
Palavras-chave
explosões solares , sub-thz 𝑏𝑢𝑟𝑠𝑡𝑠 , transmissão atmosférica sub-thz , espectro de explosões em rádio
Assuntos Scopus
Citação
FERNANDES, Luís Olavo de Toledo. Tendências espectrais de explosões solares em frequências Sub-THz. 2017. 81 f. Tese( Ciências e Aplicações Geoespaciais) - Universidade Presbiteriana Mackenzie, São Paulo.