The Galactic oxygen abundance gradient

Stephen J. Smartt*, William Robert J. Rolleston

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

108 Citations (Scopus)


We have previously published medium- to high-resolution spectroscopic observations of early B-type main-sequence objects, lying in 18 young, stellar clusters and associations or the general disk population, over galactocentric distances 6 ≲ Rg ≲ 18 kpc. Using a homogeneous subset of stars with similar atmospheric parameters, we have reanalyzed the O II line spectra using non-LTE line formation calculations. We derive an oxygen abundance gradient of -0.07 ± 0.01 dex kpc-1, which should be representative of the present-day interstellar medium within the Galaxy. This extensive and self-consistent data set represents a considerable advance on previous attempts to measure the Galactic oxygen abundance gradient using early-type stars and produces a significant gradient for the first time. The outer disk is well sampled, which gives the result statistical significance, and the discrepancies with previous similar studies are discussed. We compare this new result to those derived using Galactic H II regions and planetary nebulae and conclude that the different methods now appear to produce consistent agreement.

Original languageEnglish
Pages (from-to)L47-L50
JournalAstrophysical Journal
Issue number1 PART II
Publication statusPublished - 01 Jan 1997


  • Galaxy: abundances
  • Galaxy: evolution
  • Stars: abundances
  • Stars: atmospheres
  • Stars: early-type

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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