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Discovery of Eight z ~ 6 Quasars from Pan-STARRS1

Bañados, E.; Venemans, B.P.; Morganson, E.; Decarli, R.; Walter, F.; Chambers, K.C.; Rix, H.-W.; Farina, E.P.; Fan, X.; Jiang, L.; McGreer, I.; De Rosa, G.; Simcoe, R.; Weiß, A.; Price, P.A.; Morgan, J.S.; Burgett, W.S.; Greiner, J.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E.A.; Metcalfe, N.; Stubbs, C.W.; Sweeney, W.; Tonry, J.L.; Wainscoat, R.J.; Waters, C.

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E. Bañados

B.P. Venemans

E. Morganson

R. Decarli

F. Walter

K.C. Chambers

H.-W. Rix

E.P. Farina

X. Fan

L. Jiang

I. McGreer

G. De Rosa

R. Simcoe

A. Weiß

P.A. Price

J.S. Morgan

W.S. Burgett

J. Greiner

N. Kaiser

R.-P. Kudritzki

E.A. Magnier

C.W. Stubbs

W. Sweeney

J.L. Tonry

R.J. Wainscoat

C. Waters


High-redshift quasars are currently the only probes of the growth of supermassive black holes and potential tracers of structure evolution at early cosmic time. Here we present our candidate selection criteria from the Panoramic Survey Telescope & Rapid Response System 1 and follow-up strategy to discover quasars in the redshift range 5.7 lsim z lsim 6.2. With this strategy we discovered eight new 5.7 ≤ z ≤ 6.0 quasars, increasing the number of known quasars at z > 5.7 by more than 10%. We additionally recovered 18 previously known quasars. The eight quasars presented here span a large range of luminosities (–27.3 ≤ M 1450 ≤ –25.4; 19.6 ≤ z P1 ≤ 21.2) and are remarkably heterogeneous in their spectral features: half of them show bright emission lines whereas the other half show a weak or no Lyα emission line (25% with rest-frame equivalent width of the Lyα +N V line lower than 15 Å). We find a larger fraction of weak-line emission quasars than in lower redshift studies. This may imply that the weak-line quasar population at the highest redshifts could be more abundant than previously thought. However, larger samples of quasars are needed to increase the statistical significance of this finding.


Bañados, E., Venemans, B., Morganson, E., Decarli, R., Walter, F., Chambers, K., …Waters, C. (2014). Discovery of Eight z ~ 6 Quasars from Pan-STARRS1. Astronomical Journal, 148(1), Article 14.

Journal Article Type Article
Acceptance Date Apr 19, 2014
Publication Date Jul 1, 2014
Deposit Date Jun 16, 2015
Publicly Available Date Jun 30, 2015
Journal Astronomical Journal
Print ISSN 0004-6256
Electronic ISSN 1538-3881
Publisher IOP Publishing
Peer Reviewed Peer Reviewed
Volume 148
Issue 1
Article Number 14
Keywords Cosmology: observations, Quasars: emission lines, Quasars: general, Surveys.


Published Journal Article (794 Kb)

Copyright Statement
© 2014. The American Astronomical Society. All rights reserved.

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