High-resolution profiles of the diffuse interstellar features at 6379 and 6614 A

Abstract

view Abstract Citations (23) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS High-resolution profiles of the diffuse interstellar features at 6379 and 6614 Å. Welter, G. L. ; Savage, B. D. Abstract High-resolution profiles (AA 0.2 A) of the diffuse interstellar features at 6379 and 6614 A in 13 heavily reddened stars were obtained with the Wisconsin echelle spectrograph at the Cassegrain focus of the Mayall 4 m telescope. The feature at A6614 is observed to be asymmetrical, with its steep side toward the blue. In contrast, the feature at A6379 is symmetrical. Attempts to fit Fano autoionization profiles to the observed data yielded unsatisfactory results because the observed features do not exhibit the broad wings that characterize the autoionization process. The theoretical profiles for an alternate process, pure electronic impurity absorption lines in small cold grains, provide an excellent fit to the observed A6379 profile but do not satisfactorily explain that of A6614. If this solid state process is the cause of the feature at 6379 A, the symmetry of the profile can be used to infer information on size upper limits of the host grains. For a variety of plausible host materials, grain radii of less than about 1000 A are implied. Subject headings: atomic processes - interstellar: matter - line profiles Publication: The Astrophysical Journal Pub Date: August 1977 DOI: 10.1086/155414 Bibcode: 1977ApJ...215..788W Keywords: Astronomical Spectroscopy; Interstellar Matter; Line Spectra; Absorption Spectra; Autoionization; High Resolution; Spectral Resolution; Spectrographs; Astrophysics full text sources ADS | data products SIMBAD (13)