2006/08/04 by S. Muller, Sebastien Muller, Michel Guelin +7 · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Bulge #Galaxies: Formation, Evolution, Phenomena #Galaxy #Line (geometry) #Milky Way #Plateau de Bure Interferometer #Quasar #Redshift #Spectral line #Spiral galaxy #astro-ph
paper · pdf · doi:10.1051/0004-6361:20065187
accepted in A&A
arxiv created 2006/08/04 · openalex publication_date 2006/08/04 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
With the Plateau de Bure interferometer, we have measured the C, N, O and S isotopic abundance ratios in the arm of a spiral galaxy with a redshift of 0.89. The galaxy is seen face-on according to HST images. Its bulge intercepts the line of sight to the radio-loud quasar PKS 1830-211, giving rise at mm wavelengths to two Einstein images located each behind a spiral arm. The arms appear in absorption in the lines of several molecules, giving the opportunity to study the chemical composition of a galaxy only a few Gyr old. The isotopic ratios in this spiral galaxy differ markedly from those observed in the Milky Way. The 17O/18O and 14N/15N ratios are low, as one would expect from an object too young to let low mass stars play a major role in the regeneration of the gas.