Physics of formation of FeII lines outside LTE : proceedings of the 94th Colloquium of the International Astronomical Union, held in Anacapri, Capri Island, Italy, 4-8 July 1986

The same kind of physics is frequently common to very different fields of Astrophysics, so experts in each of these fields have often much to learn from each others. It was therefore logical that the International Astronomical Union should sponsor a colloquium about an ion which pro­ duces many spectral lines that can be used as a diagnostic for many sorts of objects, and which may sometimes have a major influence on physical processes occurring in astro­ physical sources. The lines of singly ionized iron (FeII) are present in absorption and emission in the spectra of objects such as the Sun, cool stars, circumstellar envelopes of hot stars, novae, diffuse nebulae including the supernova remnants, and active galactic nuclei. These lines are very often formed far from LTE, and their interpretation is not easy in view of the complex Grotrian diagram for FeII, and the gaps in the knowledge of various physical parameters. In addition, the density of very strong FeII lines becomes very large in the ultraviolet, and the lines can play a major role in the line blanketing. They need therefore to be taken into account in any energy balance argument. Front Matter....Pages i-xiii General Introduction to the “FE II Problem”....Pages 1-8 FeII Reference Catalogue....Pages 9-10 Front Matter....Pages 11-11 The Laboratory Spectrum and Atomic Structure of Fe II....Pages 13-34 New Laboratory Recordings of Fe II in the IUE Region....Pages 35-39 Semiempirical Determination of Fe II Oscillator Strengths....Pages 41-43 Theoretical determinations of Fe II atomic parameters....Pages 45-50 Calculations of Transition Probabilities for Forbidden Lines in the 3d 7 Configuration in Fe II.....Pages 51-61 Accidental Degeneracy Between Doubly Excited States in Fe II....Pages 63-65 Experimental Determination of FeII gf-Values: Review Of Available Data and Works in Progress....Pages 67-78 A Photospheric Solar Iron Abundance from Weak Fe II Lines....Pages 79-82 Empirical GF-Determination from the Solar Spectrum....Pages 83-92 Front Matter....Pages 93-93 FE II Emission Line Profiles in the Ultraviolet Spectrum of Cool, Luminous Stars....Pages 95-105 Observation of FeII in Cool Variables....Pages 107-113 Ultraviolet Fe II Emission Lines in Novae....Pages 115-124 FE II in Luminous Hot Stars....Pages 125-133 Fe II Lines in Herbig Ae Stars....Pages 135-142 Fe II Line Profiles Variability in the Herbig Be Star Z CMa....Pages 143-148 A Transient FE II Phenomenon in the Optical Spectrum of the Be/X Ray Binary System HDE 245770/A0535+26....Pages 149-153 FeII Lines in the Palomar Bright Quasar Survey....Pages 155-159 Observations of Fe II in Active Galactic Nuclei....Pages 161-175 Front Matter....Pages 93-93 FeII Lines in the Ultraviolet Spectra of Type I Supernovae....Pages 177-177 Infrared Lines of [FeII] from Supernova Remnants....Pages 179-181 Front Matter....Pages 183-183 The NLTE Formation of Iron Lines in the Solar Photosphere....Pages 185-210 Stark Broadening of the Fe II Lines in the Solar and Stellar Spectra....Pages 211-216 Fe II Lines in the Presence of Photospheric Oscillations....Pages 217-221 Ultraviolet FEII Emission from Cool Star Chromospheres....Pages 223-234 On the Excitation of the Fe II Multiplet UV 191 in Stellar Spectra....Pages 235-241 Doubly Excited Fe II Lines in the A Star 21 Pegasi....Pages 243-245 The Formation of FeII Emission Lines....Pages 247-257 Formation of FEII Lines in AGN....Pages 259-266 FeII and Balmer continuum emission in AGNs....Pages 267-271 A Computer Program for Solving Multi-Level non-LTE Radiative Transfer Problems in Moving or Static Atmospheres....Pages 273-275 Semi-Empirical Methods of Analysis of FeII Emission and Absorption Lines Formed In Diffuse Media....Pages 277-293 The UV Fe II Emissions of the Symbiotic Star CH Cyg....Pages 295-300 Analysis of the FeII Lines in the Ultraviolet Spectrum of the VV Cep Star KQ Puppis....Pages 301-305 FeII Spectral Synthesis of the Ultraviolet Spectrum of Hot Stars with Cool Winds....Pages 307-310 Front Matter....Pages 311-311 Future Laboratory Work on Fe II....Pages 313-315 Fe II Prospects in Solar Physics....Pages 317-320 Prospectives of Ground Based Observations....Pages 321-322 Space Telescope and the Fe II Problem....Pages 323-328 Front Matter....Pages 311-311 Can We Bridge the Gap Between Observation and Theory?....Pages 329-329 Concluding Remarks....Pages 331-340 Back Matter....Pages 341-349