Observations of diffuse interstellar features in the spectra of dust-embedded and field stars.
Abstract
Summary. Observations are presented here of twelve interstellar features of the spectra of dust-embedded and field stars in comparable direction in the Galactic plane, the wavelength range being nm. The spectra were obtained at a dispersion of 6 um mm-' with the Cassegrain spectrograph of the 98" Isaac Newton telescope of the Royal Greenwich Observatory. Equivalent widths, central depths, half widths and central wavelengths of these features have been studied. It is found that their relative strengths, widths and positions are the same for dust-embedded as for field stars. The lack of correlation between the strengths of sodium D lines and diffuse lines for the stars in and near the association Cyg OB 2 (VI Cyg) is very striking. It has been suggested that the heavily reddened members of Cyg OB 2 (vI Cyg) have no circumstellar shells but are located in the densest regions of the parent dust cloud. The present observations endorse this view. Key words: diffuse interstellar lines - interstellar matter
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 1973
- Bibcode:
- 1973A&A....26...17B