@Article{FernandesKCCKMPRV:2017:SpTrSo,
author = "Fernandes, L. O. T. and Kaufmann, P. and Correia, Em{\'{\i}}lia
and Castro, C. G. Gim{\'e}nez de and Kudaka, A. S. and Marun, A.
and Pereyra, P. and Raulin, J. P. and Valio, A. B. M.",
affiliation = "{Universidade Presbiteriana Mackenzie} and {Universidade
Presbiteriana Mackenzie} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Universidade Presbiteriana Mackenzie} and
{Universidade Presbiteriana Mackenzie} and Instituto de Ciencias
Astron{\'o}micas, de la Tierra y del Espacio (CONICET) and
{Complejo Astron{\^o}mico El Leoncito (CONICET)} and
{Universidade Presbiteriana Mackenzie} and {Universidade
Presbiteriana Mackenzie}",
title = "Spectral trends of solar bursts at sub-THz frequencies",
journal = "Solar Physics",
year = "2017",
volume = "292",
number = "1",
keywords = "Solar flares · Sub-THz bursts · Sub-THz atmospheric transmission ·
Radio-bursts spectra.",
abstract = "Previous sub-THz studies were derived from single-event
observations. We here analyze for the first time spectral trends
for a larger collection of sub-THz bursts. The collection 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) in 2012 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 completed with
microwave data obtained by the Radio Solar Telescope Network, when
available. We critically evaluate 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 a uniform flux scale criterion for all events.
The sub-THz bursts were searched during reported GOES soft X-ray
events of class C or larger, for periods common to SST
observations. Seven out of 16 events exhibit spectral maxima in
the range 5 40 GHz with fluxes decaying at sub-THz frequencies
(three of them associated to GOES class X, and four to class M).
Nine out of 16 events exhibited the sub-THz spectral component. In
five of these events, the sub-THz emission fluxes increased with a
separate frequency from that of the microwave spectral component
(two classified as X and three as M), and four events have only
been detected at sub-THz frequencies (three classified as M and
one as C). The results suggest that the THz component might be
present throughout, with the minimum turnover frequency increasing
as a function of the energy of the emitting electrons. The
peculiar nature of many sub-THz burst events requires further
investigations of bursts that are examined from SST observations
alone to better understand these phenomena.",
doi = "10.1007/s11207-016-1043-6",
url = "http://dx.doi.org/10.1007/s11207-016-1043-6",
issn = "0038-0938 and 1573-093X",
language = "en",
targetfile = "fernandes-spectral.pdf",
urlaccessdate = "27 abr. 2024"
}