An investigation of CN-sensitive spectral indices using synthetic spectra

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Astronomical Journal; (USA)

DOI:https://doi.org/10.1086/115365· OSTI ID:6904862

Tripicco, M J; Bell, R A ^[1]

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1. Maryland Univ., College Park (USA)

The characteristics of several CN-sensitive spectral indices measured from the Rose (1985) system from a grid of synthetic stellar spectra are examined and compared to those of field stars. The spectral indices considered include an index designed to measure spectral type in late-type stars, and three indices which have previously shown anomalous CN-band strengths in the integrated spectra of metal-rich Galactic and M31 globular clusters. The models are shown to accurately reproduce the variation in the spectral type index, H-delta/Fe I, as a function of temperature (from 4500 to 6500 K) and metallicity in the dwarfs. The comparison of the models with the field stars illustrates that the stronger 3883-A CN absorption in giants, relative to dwarfs of the same spectral type, is largely due to the mixing of CN-processed material into the atmospheres of the giants and not to the surface gravity dependence of the band strength. 28 refs.

• OSTI ID: 6904862
• Journal Information: Astronomical Journal; (USA), Journal Name: Astronomical Journal; (USA) Vol. 99; ISSN 0004-6256; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CARBON ISOTOPES
CHEMICAL COMPOSITION
CONFIGURATION
CYANOGEN
DWARF STARS
GALAXIES
GIANT STARS
GRAVITATION
ISOTOPES
MATHEMATICAL MODELS
MIXING
SPECTRA
SPIRAL CONFIGURATION
STAR CLUSTERS
STARS
STELLAR ATMOSPHERES