Possible Detection of Lyα Fluorescence from a Damped Lyα System at Redshiftz∼ 2.8

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Abstract
We have detected Lyman-alpha emission from a damped Lyman-alpha system (DLA) that lies near the bright quasar HS1549+1919. The DLA has the same redshift as HS1549+1919 and was discovered in the spectrum of a faint QSO that lies 49" away (380 proper kpc). The emission line's luminosity, double-peaked profile, and small spatial separation from the DLA suggest that it may be fluorescent Lyman-alpha emission from gas that is absorbing the nearby QSO's radiation. If this is the case, our observations show that the DLA has a size of at least 1.5" and that the QSO's luminosity one million years ago was similar to its luminosity today. A survey for similar systems within 1' of bright QSOs would put interesting limits on the mean quasar lifetime.Comment: 6.1 pages including 4 figures; accepted for publication in the Ap
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