Show simple item record

dc.contributor.authorWang, S.
dc.contributor.authorJiang, L.
dc.contributor.authorShen, Y.
dc.contributor.authorHo, L.C.
dc.contributor.authorVestergaard, M.
dc.contributor.authorBañados, E.
dc.contributor.authorWillott, C.J.
dc.contributor.authorWu, J.
dc.contributor.authorZou, S.
dc.contributor.authorYang, J.
dc.contributor.authorWang, F.
dc.contributor.authorFan, X.
dc.contributor.authorWu, X.-B.
dc.date.accessioned2022-04-11T23:17:58Z
dc.date.available2022-04-11T23:17:58Z
dc.date.issued2022
dc.identifier.citationWang, S., Jiang, L., Shen, Y., Ho, L. C., Vestergaard, M., Bañados, E., Willott, C. J., Wu, J., Zou, S., Yang, J., Wang, F., Fan, X., & Wu, X.-B. (2022). Metallicity in Quasar Broad-line Regions at Redshift ∼6. Astrophysical Journal.
dc.identifier.issn0004-637X
dc.identifier.doi10.3847/1538-4357/ac3a69
dc.identifier.urihttp://hdl.handle.net/10150/663936
dc.description.abstractBroad-line regions (BLRs) in high-redshift quasars provide crucial information on chemical enrichment in the early universe. Here we present a study of BLR metallicities in 33 quasars at redshift 5.7 < z < 6.4. Using the near-IR spectra of the quasars obtained from the Gemini telescope, we measure their rest-frame UV emission-line flux and calculate flux ratios. We then estimate BLR metallicities with empirical calibrations based on photoionization models. The inferred median metallicity of our sample is a few times the solar value, indicating that the BLR gas had been highly metal enriched at z ∼6. We compare our sample with a low-redshift quasar sample with similar luminosities and find no evidence of redshift evolution in quasar BLR metallicities. This is consistent with previous studies. The Fe ii/Mg ii flux ratio, a proxy for the Fe/α element abundance ratio, shows no redshift evolution as well, further supporting rapid nuclear star formation at z ∼6. We also find that the black hole mass-BLR metallicity relation at z ∼6 is consistent with the relation measured at 2 < z < 5, suggesting that our results are not biased by a selection effect due to this relation. © 2022. The Author(s). Published by the American Astronomical Society.
dc.language.isoen
dc.publisherIOP Publishing Ltd
dc.rightsCopyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.titleMetallicity in Quasar Broad-line Regions at Redshift ∼6
dc.typeArticle
dc.typetext
dc.contributor.departmentSteward Observatory, University of Arizona
dc.identifier.journalAstrophysical Journal
dc.description.noteOpen access journal
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.
dc.eprint.versionFinal published version
dc.source.journaltitleAstrophysical Journal
refterms.dateFOA2022-04-11T23:17:58Z


Files in this item

Thumbnail
Name:
Wang_2022_ApJ_925_121.pdf
Size:
5.271Mb
Format:
PDF
Description:
Final Published Version

This item appears in the following Collection(s)

Show simple item record

Copyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.
Except where otherwise noted, this item's license is described as Copyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.