Atividade solar em comprimentos de onda mm e sub-mm e sua associação com uma ejeção de massa coronal
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Tipo
Dissertação
Data de publicação
2015-06-17
Periódico
Citações (Scopus)
Autores
Ramírez, Ray Fernando Hidalgo
Orientador
Kaufmann, Pierre
Título da Revista
ISSN da Revista
Título de Volume
Membros da banca
Válio, Adriana Benetti Marques
Correia, Emilia
Fernandes, Francisco Carlos Rocha
Fauth, Anderson Campos
Correia, Emilia
Fernandes, Francisco Carlos Rocha
Fauth, Anderson Campos
Programa
Ciências e Aplicações Geoespaciais
Resumo
Solar flares radio emissions provide detailed information on the energy release,
particle acceleration, heating processes and plasma conditions at the sites
where the radiation is generated. This study focuses in radio emission from millimeter,
sub-millimeter and another complementary wavelengths obtained by recent
observations that might improve the understanding of processes from the low chromosphere
to the corona. Here we study a GOES class X1.7 flare on January 27,
2012 detected by the Solar Sub-millimeter Telescope (SST) at 212 and 405 GHz,
and by the solar radio polarimeters (POEMAS) at 45 and 90 GHz. LASCO C2 coronagraph
observed a coronal mass ejection (CME) with possible physical connection
with phenomena observed at radio-frequencies, including changes in polarization degree
(45 and 90 GHz) and enhancements of scintillation index (212 and 405 GHz).
The complementary radio observations were obtained by the Radio Solar Telescopes
Network (RSTN) at the single frequencies 0.2, 0.4, 0.6, 1.4, 2.7, 4.9, 8.8 and 15.4
GHz and at the 25 - 180 MHz band, and by the Green Bank Solar Radio Burst
Spectrometer (GBSRBS) at the 100 - 300 MHz and 300 - 1200 MHz bands. The
solar flare exhibits a complex time structure at microwaves consisting of three major
enhancements. Type III-like metric and decametric bursts were accompanied
by small polarized burst at 45 and 90 GHz with polarization degrees of 0.09 and
0.12, suggesting changes in the magnetic field strength the order of 700 and 2000 G,
respectively. SST detected one impulsive burst and significant 10% enhancements
of scintillation index intermittently throughout the event. The CME launch time
inferred by back extrapolation of the LASCO coronagraph observations to the solar
limb coincides approximately in time to the changes in polarization degree, suggesting
that CME might be a result of a magnetic transient causing an instability
generating the subsequent impulsive structures.
Descrição
Palavras-chave
explosão solar em polarização , ejeção de massa coronal , pulsações
sub-mm , polarization solar flare , coronal mass ejection , sub-mm pulsations
Assuntos Scopus
Citação
RAMÍREZ, Ray Fernando Hidalgo. Atividade solar em comprimentos de onda mm e sub-mm e sua associação com uma ejeção de massa coronal. 2015. 55 f. Dissertação (Mestrado em Engenharia) - Universidade Presbiteriana Mackenzie, São Paulo, 2015.