Interstellar medium and the highly ionized species observed in the spectrum of the nearby white dwarf G191-B2B
High-resolution spectra of the neargy (48 pc) white dwarf G191-B2B obtained with the International Ultraviolet Explorer (IUE) reveal sharp resonance lines of N V, C IV, and Si IV. The origin of these features is most likely linked to the white dwarf, possibly being formed in an expanding halo around the star. Interstellar lines of C II, N I, Mg II, Si II, Fe II are also seen in the spectrum. Analysis of these features indicates an average neutral hydrogen number density, n/sub Htsi/ = 6.4 x 10/sup -3/, for this line of sight. In combination with the recent EUV and soft X-ray results, we interpret this to mean that the interstellar medium in the most immediate solar vicinity is of the ''normal'' density (nroughly-equal0.1 cm/sup -3/) of lower ionization, while just beyond it, at least in some directions, is a hot, lower density plasma. These results are apparently in conflict with the model of the interstellar medium by McKee and Ostriker in its present form.
- Research Organization:
- Astronomy Department, Computer Sciences Corporation
- OSTI ID:
- 6115385
- Journal Information:
- Astrophys. J., Lett. Ed.; (United States), Vol. 248:3
- Country of Publication:
- United States
- Language:
- English
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GENERAL PHYSICS
WHITE DWARF STARS
CHEMICAL COMPOSITION
ULTRAVIOLET SPECTRA
CARBON IONS
HYDROGEN
INTERSTELLAR SPACE
NITROGEN IONS
SILICON IONS
SPECTRAL DENSITY
SPECTROSCOPIC CURVE OF GROWTH
STELLAR ATMOSPHERES
ATMOSPHERES
CHARGED PARTICLES
DIAGRAMS
DWARF STARS
ELEMENTS
FUNCTIONS
IONS
NONMETALS
OPTICAL DEPTH CURVE
SPACE
SPECTRA
SPECTRAL FUNCTIONS
STARS
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources