Closed coronal structures III. Comparison of static models with x-ray, EUV, and radio observations

Journal Article · Wed Jul 15 04:00:00 EDT 1981 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159081· OSTI ID:5973572

Pallavicini, R; Peres, G; Serio, S; Vaiana, G S; Golub, L; Rosner, R

We have used numerical models of static coronal loops in energy balance for comparison with soft X-ray, extreme ultraviolet, and centimetric observations of a solar active region. We find that simple static models with thermal conductive flux vanishing at the loop base are able to reproduce satisfactorily the observed properties in the upper portion (T> or approx. =10/sup 5/ K) of loop structures ranging from compact, high-pressure loops (with Lroughly-equal3 x 10/sup 9/ cm and p/sub 0/roughly-equal5 dyn cm/sup -2/) in the core of the region, to more extended, fainter loops (with Lroughly-equal9 x 10/sup 9/ cm, p/sub 0/roughly-equal1 dyn cm/sup -2/), and to large-scale loops (with Lroughly-equal2 x 10/sup 10/ cm, p/sub 0/roughly-equal0.2 dyn cm/sup -2/) interconnecting different active regions. We investigate the effects of changing loop parameters, such as heating scale height and loop cross section, and we argue that, in contrast to our present approach, scaling laws cannot be used to discriminate between different static energy balance models. We find some discrepancy between model predictions and observations for the lower sections of loop structures (at T< or approx. =10/sup 5/ K), and we also find that static energy balance models are not consistent with cool ''spiky'' structures observed above sunspots. We discuss possible causes of the discrepancy

• Research Organization: Osservatorio Astrofisico di Arcetri, Firenze, Italy
• OSTI ID: 5973572
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 247:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics &amp; Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
ELECTROMAGNETIC RADIATION
EMISSION
ENERGY BALANCE
ENERGY TRANSFER
EXTREME ULTRAVIOLET RADIATION
HEAT TRANSFER
MATHEMATICAL MODELS
RADIATIONS
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR CORONA
SPECTRA
STAR MODELS
SUNSPOTS
THERMAL CONDUCTION
ULTRAVIOLET RADIATION
ULTRAVIOLET SPECTRA
X-RAY SPECTRA