EDP Sciences
Free access
Volume 383, Number 2, February IV 2002
Page(s) 653 - 660
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20011759

A&A 383, 653-660 (2002)
DOI: 10.1051/0004-6361:20011759

Models for solar magnetic loops

I. A simple theoretical model and diagnostic procedure
M. Landini1 and E. Landi2, 3

1  Dipartimento di Astronomia e Scienza dello Spazio, Università di Firenze, Italy
2  Max-Planck-Institut für Aeronomie, Katlenburg-Lindau, Germany
3  Naval Research Laboratory, Washington DC, 20375-5320, USA

(Received 27 October 2000 / Accepted 28 November 2001)

In the present paper the quasi-static model of Landini & Monsignori Fossi (1975) for coronal loops is improved and a simple diagnostic procedure is developed to compare the most important physical properties of the model with a set of spectral observations of loops such as those obtained by the CDS and SUMER instruments on SOHO. The model assumes quasi-static and isobaric conditions and solves the energy equation among radiative losses, a constant heating function and heat conduction. The model is allowed to have a variable loop section. To better match the latest observational results, an isothermal section of the loop is added at the top of the loop model; its effects on the diagnostic technique and on the shape of the unknown heating function are discussed. A numerical simulation is shown and the effect of the isothermal region is discussed. In a second paper (Brkovic et al. 2002, Paper II) the present model will be compared with observations from the SOHO satellite.

Key words: Sun: corona -- techniques: miscellaneous

Offprint request: E. Landi, landi@poppeo.nrl.navy.mil

© ESO 2002