Continuous absorption and depression in the spectrum of Sun in region λ = 650...820 nm
Heading:
| 1Vavrukh, MV, 2Vasilieva, IE, 1Stelmakh, OM, 1Tyshko, NL 1Ivan Franko National University of Lviv, Lviv, Ukraine 2Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine |
| Kinemat. fiz. nebesnyh tel (Online) 2016, 32(3):40-62 |
| Start Page: Solar Physics |
| Language: Russian |
Abstract: The results of the calculation of cross-section of the basic processes (photoionization ion , excited hydrogen atoms and absorption of the photons by “free” electrons, that are in partially ionized plasma photosphere) which form continuous absorption in the photosphere of the Sun-type stars in the visible and infrared regions of the spectrum. The effective cross-section of hydrogen, that matches the observed data or the results of laboratory experiments was introduced. It was concluded that its non-monotonic behavior in the spectral region λ = 650—820 nm was caused by photoionization of excited hydrogen atoms. The continuous absorption factor for plane-parallel model of Sun was calculated as a function of wavelength and coordinates. For the first time it was investigated its spectral features in above-mentioned region of spectrum was stipulated by structure of effective cross-section. The spectral dependence of the radiation intensity of the center of solar disk in the continuous spectrum λ = 650—850 nm was investigated. The calculation results are in good agreement with observed data. It was shown that the deviation of the observed intensity radiation from the Planck distribution (depression) was caused by processes of photoionization of excited hydrogen atoms, that are in states with first quantum number n = 3. The averaged relative deviation in region λ = 650—820 nm is about 4 %. It was determined that the value of depression effect has a significant dependence on the effective temperature of the photosphere of the Sun-type stars. |
| Keywords: depression 650—850 nm, infrared regions of the spectrum, the Sun |
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