Busca avançada
Ano de início
Entree
(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

The Submillimeter Active Region Excess Brightness Temperature during Solar Cycles 23 and 24

Texto completo
Autor(es):
Gimenez de Castro, C. Guillermo [1, 2] ; Pereira, Andre L. G. [2] ; Valle Silva, J. Fernando [2] ; Selhorst, Caius L. [3] ; Mandrini, Cristina H. [1, 4] ; Cristiani, German D. [1, 4] ; Raulin, Jean-Pierre [2] ; Valio, Adriana [2]
Número total de Autores: 8
Afiliação do(s) autor(es):
[1] CONICET UBA, Inst Astron & Fis Espacio, Buenos Aires, DF - Argentina
[2] Ctr Radio Astron & Astrofis Mackenzie, Rua Consolacao 896, BR-01302907 Sao Paulo, SP - Brazil
[3] Univ Cidade Sao Paulo, Univ Cruzeiro Sul, Nucleo Astrofis, Sao Paulo, SP - Brazil
[4] Univ Buenos Aires, Fac Ciencias Exactas & Nat, RA-1428 Buenos Aires, DF - Argentina
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: ASTROPHYSICAL JOURNAL; v. 902, n. 2 OCT 2020.
Citações Web of Science: 0
Resumo

We report the temporal evolution of the excess brightness temperature Delta T-b above solar active regions (ARs) observed with the Solar Submillimeter Telescope (SST) at 212 (lambda = 1.4 mm) and 405 GHz (lambda = 0.7 mm) during Cycles 23 and 24. Comparison with the sunspot number (SSN) yields a Pearson's correlation coefficient R = 0.88 and 0.74 for 212 and 405 GHz, respectively. Moreover, when only Cycle 24 is taken into account the correlation coefficients go to 0.93 and 0.81 for each frequency. We derive the spectral index alpha between SST frequencies and find a slight anticorrelation with the SSN (R = -0.25); however, since the amplitude of the variation is lower than the standard deviation we cannot draw a definite conclusion. Indeed, alpha remains almost constant within the uncertainties with a median value of 0 characteristic of an optically thick thermal source. Since the origin of the AR submillimeter radiation is thermal continuum produced at chromospheric heights, the strong correlation between Delta T-b and the magnetic cycle evolution could be related to the available free magnetic energy to be released in reconnection events. (AU)

Processo FAPESP: 13/24155-3 - Diagnóstico de explosões solares em inédito intervalo espectral, de micro-ondas até frequências THz: desafios para interpretação (FLAT)
Beneficiário:Carlos Guillermo Giménez de Castro
Modalidade de apoio: Auxílio à Pesquisa - Temático