Unidentified stellar and interstellar features near 4500 A in O-type spectra

Journal Article · Mon Apr 01 00:00:00 EST 1991 · Publications of the Astronomical Society of the Pacific; (United States)

DOI:https://doi.org/10.1086/132825· OSTI ID:5504218

Morrell, N I; Walborn, N R; Fitzpatrick, E L ^[1]

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1. Kitt Peak National Observatory, Tucson, AZ (USA) Space Telescope Science Institute, Baltimore, MD (USA) Princeton University Observatory, NJ (USA)

The unidentified stellar emission lines at 4485 A and 4503 A have been detected in O main-sequence spectra by means of high-resolution, high-S/N observations. Previously these lines were known only in mid- to late-O giant and supergiant spectra; the present result indicates that they have a positive luminosity dependence, similar to that of other selective emission features in O-type spectra. These observations provide high-quality data on the little-studied interstellar diffuse band at 4502 A, the redward wing of which may overlap the stellar 4503 A emission. In lower-resolution observations of the luminous central clusters in the distant giant H II regions NGC 3603 and RCW 49, the 4502 A absorption intensity is similar to that of the stellar helium lines, while interstellar 4430 A is comparable with the hydrogen lines. 25 refs.

• OSTI ID: 5504218
• Journal Information: Publications of the Astronomical Society of the Pacific; (United States), Vol. 103; ISSN 0004-6280
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MAIN SEQUENCE STARS
EMISSION SPECTRA
CHEMICAL COMPOSITION
GIANT STARS
H2 REGIONS
HELIUM
HYDROGEN
RESOLUTION
SPECTROSCOPY
STARS
SUPERGIANT STARS
VISIBLE SPECTRA
COSMIC RADIO SOURCES
ELEMENTS
FLUIDS
GASES
NONMETALS
RARE GASES
SPECTRA
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources