2001/01/19 by Denis Burgarella, D. Burgarella, V. Buat +7 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Scientific Research and Discoveries #astro-ph
paper · pdf · doi:10.1051/0004-6361:20010107
12 pages, accepted for publication in A&A on 15 January 2001
arxiv created 2001/01/19 · openalex publication_date 2001/04/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We have used ultraviolet (200 nm) images of the local spiral galaxies M33, M51, M81, M100, M101 to compute morphological parameters of galactic disks at this wavelength: half-light radius rhl, surface brightness distributions, asymmetries and concentrations (CA). The visibility and the evolution of the morphological parameters are studied as a function of the redshift. The main results are: local spiral galaxies would be hardly observed and classified if projected at high redshifts () unless a strong luminosity evolution is assumed. Consequently, the non-detection of large galactic disks cannot be used without caution as a constraint on the evolution of galatic disks. Spiral galaxies observed in ultraviolet appear more irregular since the contribution from the young stellar population becomes predominent. When these galaxies are put in a (log A vs. log CA) diagram, they move to the irregular sector defined at visible wavelengths. Moreover, the log A parameter is degenerate and cannot be used for an efficient classification of morphological ultraviolet types. The analysis of high redshift galaxies cannot be carried out in a reliable way so far and a multi-wavelength approach is required if one does not want to misinterpret the data.