Plasma Diagnostics of Active Region Evolution and Implications for Coronal Heating
| dc.creator | Milligan, R. O. | |
| dc.creator | Gallagher, P. T. | |
| dc.creator | Mathioudakis, M. | |
| dc.creator | Keenan, F. P. | |
| dc.creator | Bloomfield, D. S. | |
| dc.date | 2005-09-08 | |
| dc.date.accessioned | 2026-07-07T06:20:14Z | |
| dc.date.available | 2026-07-07T06:20:14Z | |
| dc.description | A detailed study is presented of the decaying solar active region NOAA 10103 observed with the Coronal Diagnostic Spectrometer (CDS), the Michelson Doppler Imager (MDI) and the Extreme-ultraviolet Imaging Telescope (EIT) onboard the Solar and Heliospheric Observatory (SOHO). Electron density maps formed using Si X (356.03A/347.41A) show that the density varies from ~10^10 cm^-3 in the active region core, to ~7x10^8 cm^-3 at the region boundaries. Over the five days of observations, the average electron density fell by ~30%. Temperature maps formed using Fe XVI(335.41A)/Fe XIV(334.18A) show electron temperatures of \~2.34x10^6 K in the active region core, and ~2.10x10^6 K at the region boundaries. Similarly to the electron density, there was a small decrease in the average electron temperature over the five day period. The radiative, conductive, and mass flow losses were calculated and used to determine the resultant heating rate (P_H). Radiative losses were found to dominate the active region cooling process. As the region decayed, the heating rate decreased by almost a factor of five between the first and last day of observations. The heating rate was then compared to the total unsigned magnetic flux (Phi_tot), yielding a power-law of the form P_H ~ Phi_tot^(0.81 +/- 0.32). This result suggests that waves rather than nanoflares may be the dominant heating mechanism in this active region. | |
| dc.description | 9 pages, 11 figures. MNRAS, In Press | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0509219 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0509219 | |
| dc.identifier | Mon.Not.Roy.Astron.Soc. 363 (2005) 259-267 | |
| dc.identifier | doi:10.1111/j.1365-2966.2005.09446.x | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/95275 | |
| dc.subject | Astrophysics | |
| dc.title | Plasma Diagnostics of Active Region Evolution and Implications for Coronal Heating | |
| dc.type | text |