Facular line profiles and facular models

Abstract

view Abstract Citations (56) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Facular line profiles and facular models Chapman, G. A. Abstract Profiles for lines near 5250 A have been calculated from facular models and compared with observed profiles. The observations are from photographic and photoelectric spectra. The atomic parameters are determined by comparison of calculated profiles with those observed for the quiet sun. The effects of finite spatial resolution and a magnetic field are required to obtain agreement with observed facular line profiles. The empirical magnetic field deduced by matching observed and calculated profiles is reasonably consistent with that in the facular models. The main purpose of this paper is to show that by including the effects of scattered photospheric light and a strong magnetic field, reasonable agreement can be achieved between observed and calculated facular line profiles. Results are also presented for the wing of the Ca II K line, showing line profiles and effective filtergram contrasts for several facular models. It is concluded that observations made with weak Fraunhofer lines are not very useful for discrimination among facular models, particularly without simultaneous magnetic-field measurements. The K line may offer a better discriminator. The facular model presently favored has a magnetic field strength of about 1500 gauss at the surface of the photosphere. Publication: The Astrophysical Journal Supplement Series Pub Date: January 1977 DOI: 10.1086/190417 Bibcode: 1977ApJS...33...35C Keywords: Faculae; Light Scattering; Line Spectra; Solar Magnetic Field; Solar Spectra; Astronomical Models; Astronomical Photography; Curve Fitting; Filtergrams; Fine Structure; Fraunhofer Lines; Graphs (Charts); Magnetic Flux; Astrophysics full text sources ADS |