Two-dimensional spatial spectrum of the photospheric brightness field near to the solar disc center
✍ Scribed by V. N. Karpinsky; V. V. Mekhanikov
- Publisher
- Springer
- Year
- 1977
- Tongue
- English
- Weight
- 570 KB
- Volume
- 54
- Category
- Article
- ISSN
- 0038-0938
No coin nor oath required. For personal study only.
✦ Synopsis
From high-quality direct frames taken by the Soviet Stratospheric Solar Observatory, using coherent optical methods, the two-dimensional spatial spectrum of the photospheric brightness field was obtained (Figure 1). This spectrum is isotropic and continuous. Spectral densities if(k) and
where k is the radial wavenumber, were estimated for the solar disc centre, and their statistical uncertainty calculated, if(k) has a maximum near k = 10 -3 km -1 and then it tends to fall after that to zero frequency. The k dependence of A(k) cannot be satisfactorily approximated by a power law. For the highest frequencies studied, the spectrum falls as k -9. The measured statistical uncertainty of the spectra of individual domains for k ~< 125 x 10 -4 km -1 is in agreement with that calculated for a gaussian homogeneous field. But for a higher k the uncertainty may essentially exceed that of a gaussian homogeneous field. The true rms value for A4650 is equal to about 29%.