Excitation Sources of Oscillations in Solar Coronal Loops: A Multi-wavelength Analysis

Autor(es)

Conde C, Sandra M. ^{[1, 2]} ; Jain, Rekha ^[3] ; Jatenco-Pereira, Vera ^[2]

Afiliação do(s) autor(es)

^[1] Univ St Andrews, Sch Math & Stat, St Andrews KY16 9SS, Fife - Scotland

^[2] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao 1226, BR-05508090 Sao Paulo, SP - Brazil

^[3] Univ Sheffield, Sch Math & Stat, Sheffield S3 7RH, S Yorkshire - England

• Tipo de documento: Artigo Científico
• Fonte: Astrophysical Journal Letters; v. 890, n. 2 FEB 20 2020.
• Citações Web of Science: 0

Resumo

An investigation into the excitation sources of oscillations detected in a coronal loop structure is carried out using the images obtained with Interface Region Imaging Spectrometer (IRIS) and the Atmospheric Imaging Assembly (AIA) instrument on board the Solar Dynamics Observatory (SDO). A loop structure in the active region AR 11967 on 2014 January 28, oscillating in the vicinity of a strong eruption and an M3.6 class flare site, is clearly noticeable in SDO/AIA 171 A images. We study in detail, the oscillations with detected periods between 4 and 13 minutes and their connection in IRIS SJI 1330 A and SDO/AIA 1700 A images; both of these wavelengths sample the lower parts of the solar atmosphere. The simultaneous presence of many oscillations in the region of interest in all three wavelength passbands suggest that these oscillations were excited in the lower-chromosphere-photosphere plasma connected to the loop structure and then propagated at higher heights. We further investigate the Doppler velocity measurements from the spectrograph snapshots in IRIS C ii 1336 A, Si iv 1403 A and Mg ii k 2796 A. These show signatures of upflows in the vicinity of the loop structure's endpoints estimated from 171 A images. We suggest that some of the oscillations observed in AIA 171 A have been triggered by plasma ejections and perturbations seen in the lower layers of the solar atmosphere. Based on the estimated phase speeds, the oscillations are likely to be slow magnetoacoustic in nature. (AU)

• Processo FAPESP: 18/25306-9 - Análise tridimensional de ondas longitudinais amortecidas em loops coronais associados com flares
• Beneficiário: Sandra Milena Conde Cuellar
• Linha de fomento: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 13/10559-5 - Investigação de fenômenos de altas energias e plasmas astrofísicos: teoria, simulações numéricas, observações e desenvolvimento de instrumentação para o Cherenkov Telescope Array (CTA)
• Beneficiário: Elisabete Maria de Gouveia Dal Pino
• Linha de fomento: Auxílio à Pesquisa - Temático