2001/03/21 by Daniel D. Kelson, Garth D. Illingworth, Marijn Franx +1 · 5 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Scientific Research and Discoveries #astro-ph
paper · pdf · doi:10.1086/320252
5 pages, 4 figures; for publication in the ApJ Letters (accepted on 21 March 2001)
arxiv created 2001/03/21 · openalex publication_date 2001/05/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We present new results from a systematic study of absorption-line strengths of galaxies in clusters approaching redshifts of unity. In this Letter, we specifically compare the strengths of the high-order Balmer absorption features of Hγ and Hδ in E/S0 galaxies in the four clusters Abell 2256 ( z = 0.06), Cl 1358+62 ( z = 0.33), MS 2053-04 ( z = 0.58), and MS 1054-03 ( z = 0.83). By comparing the correlation of the Balmer line strengths with the velocity dispersions for E/S0 galaxies in the four clusters, we find moderate evolution in the zero point of the (Hδ A + Hγ A )-σ relation with redshift. The trend is consistent with the passive evolution of old stellar populations. Under the assumption that the samples can be compared directly, we use single-burst stellar population synthesis models to constrain the last major occurrences of star formation in the observed E/S0 galaxies to be z f > 2.5 (95% confidence). We have compared the evolution of the Balmer absorption with the evolution of the B -band fundamental plane and find that simple stellar population models agree very well with the data. While the best agreement occurs with a low value for Ω m , the data provide strong confirmation of the time evolution in recent stellar population models.