![]() They are characterized by their density value n 0 extrapolated down to the base of the corona and their scale-height temperature T H. The derived yearly-averaged density models along equatorial and polar diameters are consistent with isothermal and hydrostatic models. These minima are more pronounced for EW profiles than for NS ones. The widths of the brightness profiles that were averaged yearly have minima at cycle minimum (2008–2009). The electron temperature, in turn, can be derived from the comparison of the observed mean spectra on the disk with those predicted through transfer calculations from the density models derived from limb observations. The agreement between results from different frequencies, in the ranges of r where there is overlapping shows the robustness of the method. The total ranges in the heliocentric distance r are 1.15–1.60 R ⊙ (EW) and 1.0–1.4 R ⊙ (NS). Measurements of the brightness temperature T b beyond the limb allowed coronal density models to be derived in both EW and NS radial directions, with a weak dependence on the electron temperature. Images at 6 frequencies between 150 and 450 MHz for 183 quiet days between 20 were used. We study the variations of the quiet corona in brightness and size during an 8-year period and derive electron density and temperature in the corona. The 2D images obtained through rotational aperture synthesis with the Nançay Radioheliograph are suitable for quantitative exploitation. Paris-Diderot, 92195 Meudon Cedex, FranceĬontext. LESIA-Observatoire de Paris, CNRS, UPMC, Univ. Astronomical objects: linking to databases.Including author names using non-Roman alphabets.Suggested resources for more tips on language editing in the sciences Punctuation and style concerns regarding equations, figures, tables, and footnotes ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |