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Title: A SURVEY OF METAL LINES AT HIGH-REDSHIFT. I. SDSS ABSORPTION LINE STUDIES- THE METHODOLOGY AND FIRST SEARCH RESULTS FOR O VI

Journal Article · · Astronomical Journal (New York, N.Y. Online)
; ;  [1]
  1. Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

We report the results of a systematic search for signatures of metal lines in quasar spectra of the Sloan Digital Sky Survey (SDSS) data release 3 (DR3), focusing on finding intervening absorbers via detection of their O VI doublet. Here, we present the search algorithm and criteria for distinguishing candidates from spurious Ly{alpha} forest lines. In addition, we compare our findings with simulations of the Ly{alpha} forest in order to estimate the detectability of O VI doublets over various redshift intervals. We have obtained a sample of 1756 O VI doublet candidates with rest-frame equivalent width (EW) {>=}0.05 A in 855 active galactic nuclei spectra (out of 3702 objects with redshifts in the accessible range for O VI detection). This sample is further subdivided into three groups according to the likelihood of being real and the potential for follow-up observation of the candidate. The group with the cleanest and most secure candidates is comprised of 145 candidates. Sixty-nine of these reside at a velocity separation {>=}5000 km s{sup -1} from the QSO and can therefore be classified tentatively as intervening absorbers. Most of these absorbers have not been picked up by earlier, automated QSO absorption line detection algorithms. This sample increases the number of known O VI absorbers at redshifts beyond z{sub abs{>=}} 2.7 substantially.

OSTI ID:
21443238
Journal Information:
Astronomical Journal (New York, N.Y. Online), Vol. 140, Issue 3; Other Information: DOI: 10.1088/0004-6256/140/3/817; ISSN 1538-3881
Country of Publication:
United States
Language:
English