The search for diffuse interstellar bands in quasar absorption line systems
Date
2008-08-15T16:01:00Z
Authors
York, Brian A.
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Abstract
The diffuse interstellar bands (DIBs) probably arise from complex organic molecules whose strength in local galaxies correlates with neutral hydrogen column density, N(H I), and dust reddening, E(B−V). Because Damped Lyman-α systems are known to have high N(H I), and Ca II absorbers in quasar (QSO) spectra are posited to have high N(H I) and reddening, both represent promising sites for the detection of DIBs at cosmological distances. I present the results of a search for diffuse bands in seven DLAs and nine Ca II absorbers. I announce the detection of the first narrow DIBs at z>0 towards one DLA and one Ca II system. I further investigate the relative strengths of the DIBs as well as their correlations with N(H I) and E(B−V). Finally, I discuss the prospects for using DIBs to better understand the properties of quasar absorption systems, and for using DIB searches in absorption systems to better understand the properties of DIBs.
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ISM: Lines and bands, ISM: Molecules, Quasars: Absorption Lines, Quasars: Absorption Lines: DLAs, Quasars: Absorption Lines: Ca II Systems, Quasars: Individual (J0013–0024), Quasars: Individual (AO 0235+164)