The chemical compositions of 26 distant late-type supergiants and the metallicity gradient in the galactic disk

Abstract

view Abstract Citations (44) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The chemical compositions of 26 distant late-type supergiants and the metallicity gradient in the galactic disk. Luck, R. E. ; Bond, H. E. Abstract From an analysis of high-dispersion Mount Wilson spectroscopic data, we have obtained atmospheric parameters and chemical abundances for 26 distant supergiants of spectral types G through M. Iron-to-hydrogen ratios with respect to the Sun, [Fe/H], can be determined from this material with an uncertainty of ±0.2 dex. It is found that supergiants more than about 0.5 kpc from the Sun in the direction of the galactic anticenter are significantly metal-deficient relative to those in the solar neighborhood. Combining our new analyses with those published earlier by Luck for 28 additional supergiants, we derive a radial metallicity gradient d[Fe/H]/dR = -0.24 ± 0.04 kpc-1 for the region of the galactic disk between 7.7 and 10.2 kpc from the galactic center. This gradient is steeper than is found from older objects (such as field main-sequence stars, red giants, and open clusters) and suggests that the metallicity gradients in disk galaxies steepen significantly with age. Publication: The Astrophysical Journal Pub Date: October 1980 DOI: 10.1086/158334 Bibcode: 1980ApJ...241..218L Keywords: Abundance; Chemical Composition; Galactic Structure; Late Stars; Milky Way Galaxy; Supergiant Stars; Spectral Line Width; Tables (Data); Astrophysics; Galaxy:Metal Content; Late-Type Supergiants:Chemical Composition full text sources ADS | data products SIMBAD (53)