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 = "19 abr. 2021"