B. Chehade
Two more, bright, z > 6 quasars from VST ATLAS and WISE
Chehade, B.; Carnall, A.C.; Shanks, T.; Diener, C.; Fumagalli, M.; Findlay, J.R.; Metcalfe, N.; Hennawi, J.; Leibler, C.; Murphy, D.N.A.; Prochaska, J.X.; Irwin, M.J.; Gonzalez-Solares, E.
Authors
A.C. Carnall
T. Shanks
C. Diener
Professor Michele Fumagalli michele.fumagalli@durham.ac.uk
Academic Visitor
J.R. Findlay
Dr Nigel Metcalfe nigel.metcalfe@durham.ac.uk
Assistant Professor
J. Hennawi
C. Leibler
D.N.A. Murphy
J.X. Prochaska
M.J. Irwin
E. Gonzalez-Solares
Abstract
Recently, Carnall et al. discovered two bright high redshift quasars using the combination of the VST ATLAS and WISE surveys. The technique involved using the 3-D colour plane i − z: z − W1: W1 − W2 with the WISE W1(3.4 micron) and W2 (4.5 micron) bands taking the place of the usual NIR J band to help decrease stellar dwarf contamination. Here we report on our continued search for 5.7 < z < 6.4 quasars over an ≈2 × larger area of ≈3577 deg2 of the Southern Hemisphere. We have found two further z > 6 quasars, VST-ATLAS J158.6938-14.4211 at z = 6.07 and J332.8017-32.1036 at z = 6.32 with magnitudes of zAB = 19.4 and 19.7 mag respectively. J158.6938-14.4211 was confirmed by Keck LRIS observations and J332.8017-32.1036 was confirmed by ESO NTT EFOSC-2 observations. Here we present VLT X-shooter Visible and NIR spectra for the four ATLAS quasars. We have further independently rediscovered two z > 5.7 quasars previously found by the VIKING/KiDS and PanSTARRS surveys. This means that in ATLAS we have now discovered a total of six quasars in our target 5.7 < z < 6.4 redshift range. Making approximate corrections for incompleteness, we find that our quasar space density agrees with the SDSS results of Jiang et al. at M1450Å ≈ −27. Preliminary virial mass estimates based on the CIV and MgII emission lines give black hole masses in the range MBH ≈ 1 − 6 × 109M⊙ for the four ATLAS quasars.
Citation
Chehade, B., Carnall, A., Shanks, T., Diener, C., Fumagalli, M., Findlay, J., …Gonzalez-Solares, E. (2018). Two more, bright, z > 6 quasars from VST ATLAS and WISE. Monthly Notices of the Royal Astronomical Society, 478(2), 1649-1659. https://doi.org/10.1093/mnras/sty690
Journal Article Type | Article |
---|---|
Acceptance Date | Feb 23, 2018 |
Online Publication Date | Mar 19, 2018 |
Publication Date | Aug 1, 2018 |
Deposit Date | Apr 5, 2018 |
Publicly Available Date | Apr 6, 2018 |
Journal | Monthly Notices of the Royal Astronomical Society |
Print ISSN | 0035-8711 |
Electronic ISSN | 1365-2966 |
Publisher | Royal Astronomical Society |
Peer Reviewed | Peer Reviewed |
Volume | 478 |
Issue | 2 |
Pages | 1649-1659 |
DOI | https://doi.org/10.1093/mnras/sty690 |
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Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
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