2003/06/03 by I. Labbe, Ivo Labb, Gregory Rudnick +23 · 4 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Hubble Deep Field #Hubble Ultra-Deep Field #Luminous infrared galaxy #Physics #Redshift #Surface brightness #astro-ph
paper · pdf · doi:10.1086/377149
published as Astrophys.J.591:L95-L98,2003 · LaTeX, 5 pages, 2 figures, 1 table. Accepted for publication in the Astrophysical Journal Letters
arxiv created 2003/06/03 · openalex publication_date 2003/06/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Using deep near-infrared imaging of the Hubble Deep Field-South with the Infrared Spectrometer and Array Camera on the Very Large Telescope, we find six large disklike galaxies at redshifts z = 1.4-3.0. The galaxies, selected in K s (2.2 μm), are regular and surprisingly large in the near-infrared (rest-frame optical), with face-on effective radii r e = 0 65-0 9 or 5.0-7.5 h kpc in a Λ cold dark matter cosmology, comparable to the Milky Way. The surface brightness profiles are consistent with an exponential law over 2-3 effective radii. The Wide Field Planetary Camera 2 morphologies in Hubble Space Telescope imaging (rest-frame UV) are irregular and show complex aggregates of star-forming regions ~2'' (~15 h kpc) across, symmetrically distributed around the K s -band centers. The spectral energy distributions show clear breaks in the rest-frame optical. The breaks are strongest in the central regions of the galaxies and can be identified as the age-sensitive Balmer/4000 Å break. The most straightforward interpretation is that these galaxies are large disk galaxies; deep near-infrared data are indispensable for this classification. The candidate disks constitute 50% of galaxies with L V ≳ 6 × 10 10 h L ☉ at z = 1.4-3.0. This discovery was not expected on the basis of previously studied samples. In particular, the Hubble Deep Field-North is deficient in large galaxies with the morphologies and profiles we report here.