DETECTION OF A SUPERSTRONG 2175 A ABSORPTION GALAXY AT z = 0.8839 TOWARD THE QUASAR SDSS J100713.68+285348.4

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/708/1/742· OSTI ID:21392442

Hongyan, Zhou; Honglin, Lu; Tinggui, Wang; Peng, Jiang ^[1]; Jian, Ge ^[2]; Weimin, Yuan; Hongguang, Shan ^[3]

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1. Key Laboratory for Research in Galaxies and Cosmology, University of Sciences and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026 (China)
2. Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States)
3. National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China)

We report a superstrong 2175 A absorption galaxy at a redshift of z{sub G} = 0.8839 toward the background quasar SDSS J100713.68+285348.4 at z{sub Q} = 1.047 identified from the Sloan Digital Sky Survey (SDSS) data. The bump is the strongest ever known, about 2.5 times the average in the Galactic interstellar extinction curves. About two dozens of narrow absorption lines are identified in this system in the SDSS and the follow-up Multiple Mirror Telescope (MMT) spectra, including Zn II, Cr II, Mn II, Si II, Fe II, Ti II, Ca II, Al III, Mg II, and Mg I. We have derived accurate measurements of the gas-phase column densities of most of these ions through their weak absorption lines. The combination of unprecedentedly strong 2175 A absorption bump strength with the measured zinc column density suggests that carbon is likely to be the main carrier of the 2175 A absorber assuming that the total abundance of the absorber relative to zinc is similar to the solar values and zinc is not heavily depleted onto dust grains. Under the same assumption, we found that dust depletion in this absorption galaxy is much less than that in the Milky Way, indicating possible different nucleosynthesis and/or chemical and interstellar medium evolution history.

• OSTI ID: 21392442
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 708; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
ABUNDANCE
CARBON
COSMIC RADIO SOURCES
DUSTS
ELEMENTS
GALAXIES
METALS
MILKY WAY
NONMETALS
NUCLEOSYNTHESIS
QUASARS
RED SHIFT
SORPTION
SPECTRA
SYNTHESIS
TELESCOPES
ZINC