Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/343495
Type: Artigo
Title: Three new VHS–DES quasars at 6.7 < z < 6.9 and emission line properties at z > 6.5
Author: Reed, S L
Abstract: We report the results from a search for z > 6.5 quasars using the Dark Energy Survey (DES) Year 3 data set combined with the VISTA Hemisphere Survey (VHS) and WISE All-Sky Survey. Our photometric selection method is shown to be highly efficient in identifying clean samples of high-redshift quasars, leading to spectroscopic confirmation of three new quasars – VDES J0244−5008 (z = 6.724), VDES J0020−3653 (z = 6.834), and VDES J0246−5219 (z = 6.90) – which were selected as the highest priority candidates in the survey data without any need for additional follow-up observations. We have obtained spectroscopic observations in the near-infrared for VDES J0244−5008 and VDES J0020−3653 as well as our previously identified quasar, VDES J0224−4711 at z = 6.50 from Reed et al. We use the near-infrared spectra to derive virial black hole masses from the full width at half-maximum of the Mg II line. These black hole masses are ≃1–2 × 109 M⊙. Combined with the bolometric luminosities of these quasars of Lbol ≃ 1–3 × 1047, these imply that the Eddington ratios are high, ≃0.6–1.1. We consider the C IV emission line properties of the sample and demonstrate that our high-redshift quasars do not have unusual C IV line properties when compared to carefully matched low-redshift samples. Our new DES + VHS z > 6.5 quasars now add to the growing census of luminous, rapidly accreting supermassive black holes seen well into the epoch of reionization
Subject: Galáxias
Country: Reino Unido
Editor: Oxford University Press
Rights: Aberto
Identifier DOI: 10.1093/mnras/stz1341
Address: https://academic.oup.com/mnras/article/487/2/1874/5505847
Date Issue: 2019
Appears in Collections:IFGW - Artigos e Outros Documentos

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