2003/05/20 by P. Snchez-Blzquez, P. Sanchez-Blazquez, J. Gorgas +5 · 2 citations
Mathematics · Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Carbon fibers #Cluster (spacecraft) #Composite number #Computer science #Environmental science #Field (mathematics) #Materials science #Mathematics #Nitrogen #Physics #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/376825
published as Astrophys.J. 590 (2003) L91-L94 · 12 pages, including 3 figures, accepted for publication in ApJL
arxiv created 2003/05/20 · openalex publication_date 2003/05/21 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Central line-strength indices were measured in the blue spectral region for a sample of 98 early-type galaxies in different environments. For most indices (Mgb and <Fe> in particular) ellipticals in rich clusters and in low-density regions follow the same index-sigma relations. However, striking spectral differences between field ellipticals and their counterparts in the central region of the Coma cluster are found for the first time, with galaxies in the denser environment showing significantly lower C4668 and CN2 absorption strengths. The most convincing interpretation of these results is a difference in abundance ratios, arising from a distinct star formation and chemical enrichment histories of galaxies in different environments. An scenario in which elliptical galaxies in clusters are fully assembled at earlier stages than their low-density counterparts is discussed.