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Title: GALEX DISCOVERY OF A DAMPED Ly{alpha} SYSTEM AT REDSHIFT z {approx} 1

Journal Article · · Astronomical Journal (New York, N.Y. Online)
 [1]; ; ;  [2]
  1. Department of Physics, College at Brockport, State University of New York, Brockport, NY 14420 (United States)
  2. Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States)

We report the first discovery of a QSO damped Ly{alpha} system (DLA) by the Galaxy Evolution Explorer (GALEX) satellite. The system was initially identified as an Mg II absorption-line system (z {sub abs} = 1.028) in the spectrum of Sloan Digital Sky Survey (SDSS) QSO J0203-0910 (z {sub em} = 1.58). The presence of unusually strong absorption due to metal lines of Zn II, Cr II, Mn II, and Fe II clearly suggested that it might be a DLA with N {sub HI} {>=} 2 x 10{sup 20} atoms cm{sup -2}. Follow-up GALEX NUV grism spectroscopy confirms that the system exhibits a DLA absorption line, with a measured H I column density of N {sub HI} = 1.50 {+-} 0.45 x 10{sup 21} atoms cm{sup -2}. By combining the GALEX N {sub HI} determination with the SDSS spectrum measurements of unsaturated metal-line absorption due to Zn II, which is generally not depleted onto grains, we find that the system's neutral-gas-phase metal abundance is [Zn/H] = -0.70 {+-} 0.22, or {approx}20% solar. By way of comparison, although this system has one of the largest Zn{sup +} column densities, its metal abundances are comparable to other DLAs at z {approx} 1. Measurements of the abundances of Cr, Fe, and Mn help to further pin down the evolutionary state of the absorber.

OSTI ID:
21301514
Journal Information:
Astronomical Journal (New York, N.Y. Online), Vol. 138, Issue 6; Other Information: DOI: 10.1088/0004-6256/138/6/1609; Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
Country of Publication:
United States
Language:
English