The temporal evolution of coronal loops observed by GOES SXI

We study the temporal evolution of coronal loops using data from the Solar X-Ray Imager (SXI) on board the Geosynchronous Operational Environmental Satellite 12 (GOES-12). This instrument provides continuous soft X-ray observations of the solar corona at a high temporal cadence permitting detailed s...

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Guardado en:
Detalles Bibliográficos
Publicado: 2007
Materias:
Sun: corona
Sun: flares
Sun: magnetic fields
Sun: X-rays, gamma rays
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v657_n2I_p1127_LopezFuentes
http://hdl.handle.net/20.500.12110/paper_0004637X_v657_n2I_p1127_LopezFuentes
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_0004637X_v657_n2I_p1127_LopezFuentes
record_format dspace
spelling paper:paper_0004637X_v657_n2I_p1127_LopezFuentes2023-06-08T14:28:53Z The temporal evolution of coronal loops observed by GOES SXI Sun: corona Sun: flares Sun: magnetic fields Sun: X-rays, gamma rays We study the temporal evolution of coronal loops using data from the Solar X-Ray Imager (SXI) on board the Geosynchronous Operational Environmental Satellite 12 (GOES-12). This instrument provides continuous soft X-ray observations of the solar corona at a high temporal cadence permitting detailed study of the full lifetime of each of several coronal loops. The observed light curves suggest three evolutionary phases: rise, main, and decay. The durations and characteristic timescales of these phases [I/(dI/dt), where I is the loop intensity] are much longer than a cooling time and indicate that the loop-averaged heating rate increases slowly, reaches a maintenance level, and then decreases slowly. This suggests that a single heating mechanism operates for the entire lifetime of the loop. For monolithic (uniformly filled) loops, the loop-averaged heating rate is the intrinsic energy release rate of the heating mechanism. For loops that are bundles of impulsively heated strands, it relates to the frequency of occurrence of individual heating events, or nanoflares. We show that the timescale of the loop-averaged heating rate is proportional to the timescale of the observed intensity variation, with a constant of proportionality of approximately 1.5 for monolithic loops and 1.0 for multistranded loops. The ratios of the radiative to conductive cooling times in the loops are some-what less than 1, putting them intermediate between the values measured previously for hotter and cooler loops. This provides further support for a trend suggesting that all loops are heated in a similar way. © 2007. The American Astronomical Society. All rights reserved. 2007 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v657_n2I_p1127_LopezFuentes http://hdl.handle.net/20.500.12110/paper_0004637X_v657_n2I_p1127_LopezFuentes
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Sun: corona
Sun: flares
Sun: magnetic fields
Sun: X-rays, gamma rays
spellingShingle Sun: corona
Sun: flares
Sun: magnetic fields
Sun: X-rays, gamma rays
The temporal evolution of coronal loops observed by GOES SXI
topic_facet Sun: corona
Sun: flares
Sun: magnetic fields
Sun: X-rays, gamma rays
description We study the temporal evolution of coronal loops using data from the Solar X-Ray Imager (SXI) on board the Geosynchronous Operational Environmental Satellite 12 (GOES-12). This instrument provides continuous soft X-ray observations of the solar corona at a high temporal cadence permitting detailed study of the full lifetime of each of several coronal loops. The observed light curves suggest three evolutionary phases: rise, main, and decay. The durations and characteristic timescales of these phases [I/(dI/dt), where I is the loop intensity] are much longer than a cooling time and indicate that the loop-averaged heating rate increases slowly, reaches a maintenance level, and then decreases slowly. This suggests that a single heating mechanism operates for the entire lifetime of the loop. For monolithic (uniformly filled) loops, the loop-averaged heating rate is the intrinsic energy release rate of the heating mechanism. For loops that are bundles of impulsively heated strands, it relates to the frequency of occurrence of individual heating events, or nanoflares. We show that the timescale of the loop-averaged heating rate is proportional to the timescale of the observed intensity variation, with a constant of proportionality of approximately 1.5 for monolithic loops and 1.0 for multistranded loops. The ratios of the radiative to conductive cooling times in the loops are some-what less than 1, putting them intermediate between the values measured previously for hotter and cooler loops. This provides further support for a trend suggesting that all loops are heated in a similar way. © 2007. The American Astronomical Society. All rights reserved.
title The temporal evolution of coronal loops observed by GOES SXI
title_short The temporal evolution of coronal loops observed by GOES SXI
title_full The temporal evolution of coronal loops observed by GOES SXI
title_fullStr The temporal evolution of coronal loops observed by GOES SXI
title_full_unstemmed The temporal evolution of coronal loops observed by GOES SXI
title_sort temporal evolution of coronal loops observed by goes sxi
publishDate 2007
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v657_n2I_p1127_LopezFuentes
http://hdl.handle.net/20.500.12110/paper_0004637X_v657_n2I_p1127_LopezFuentes
_version_ 1768542343672102912

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