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dc.contributorVirginia Tech
dc.contributor.authorDunn, J. P.
dc.contributor.authorArav, N.
dc.contributor.authorAoki, K.
dc.contributor.authorWilkins, A.
dc.contributor.authorLaughlin, C.
dc.contributor.authorEdmonds, D.
dc.contributor.authorBautista, M.
dc.identifier.citationJay P. Dunn et al. 2012. "BAL outflow contribution to AGN feedback: frequency of S IV outflows in the SDSS," ApJ 750 143 doi:10.1088/0004-637X/750/2/143
dc.description.abstractWe present a study of broad absorption line (BAL) quasar outflows that show S IV lambda 1063 and S IV* lambda 1073 troughs. The fractional abundances of S IV and C IV peak at similar value of the ionization parameter, implying that they arise from the same physical component of the outflow. Detection of the S IV* troughs will allow us to determine the distance to this gas with higher resolution and higher signal-to-noise spectra, therefore providing the distance and energetics of the ubiquitous C IV BAL outflows. In our bright sample of 156 SDSS quasars, 14% show C IV and 1.9% S IV troughs, which are consistent with a fainter magnitude sample with twice as many objects. One object in the fainter sample shows evidence of a broad S IV trough without any significant trough present from the excited state line, which implies that this outflow could be at a distance of several kpc. Given the fractions of C IV and S IV, we establish firm limits on the global covering factor on S IV that ranges from 2.8% to 21% (allowing for the k-correction). Comparison of the expected optical depth for these ions with their detected percentage suggests that these species arise from common outflows with a covering factor closer to the latter.
dc.description.sponsorshipNSF AST 0837880
dc.description.sponsorshipNASA LTSA NAG5-12867
dc.publisherIOP Publishing Ltd.
dc.subjectquasars: absorption lines
dc.subjectbroad absorption-line
dc.subjectdigital sky survey
dc.subjectlarge telescope observations
dc.subjectquasi-stellar objects
dc.subjectlyman-alpha forest
dc.subjectintrinsic absorption
dc.subjectphysical conditions
dc.subjectactive galaxies
dc.titleBAL outflow contribution to AGN feedback: frequency of S IV outflows in the SDSS
dc.title.serialAstrophysical Journal

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