Recently,Carnall et al. discovered two bright high-redshift quasars using the combination of the Very Large Telescope (VLT) Survey Telescope (VST) ATLAS and Wide-field Infrared Survey Explorer (WISE) surveys. The technique involved using the 3D colour plane i-z: z-W1: W1- W2with the WISEW1 (3.4 micron) andW2 (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 Sloan Digital Sky Survey results of Jiang et al. at M1450Å ≈ -27. Preliminary virial mass estimates based on the C IV and MgII emission lines give black hole masses in the range MBH ≈ 1-6 × 109M⊙ for the four ATLAS quasars

Chehade, B., Carnall, A., Shanks, T., Diener, C., Fumagalli, M., Findlay, J., et al. (2018). Two more, bright, z > 6 quasars from VST ATLAS and WISE. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 478(2), 1649-1659 [10.1093/mnras/sty690].

Two more, bright, z > 6 quasars from VST ATLAS and WISE

Fumagalli M.;
2018

Abstract

Recently,Carnall et al. discovered two bright high-redshift quasars using the combination of the Very Large Telescope (VLT) Survey Telescope (VST) ATLAS and Wide-field Infrared Survey Explorer (WISE) surveys. The technique involved using the 3D colour plane i-z: z-W1: W1- W2with the WISEW1 (3.4 micron) andW2 (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 Sloan Digital Sky Survey results of Jiang et al. at M1450Å ≈ -27. Preliminary virial mass estimates based on the C IV and MgII emission lines give black hole masses in the range MBH ≈ 1-6 × 109M⊙ for the four ATLAS quasars
Articolo in rivista - Articolo scientifico
Quasars: general; Quasars: individual: VST-ATLAS J158.6938-14.4211; Quasars: individual: VST-ATLAS J332.8017-32.1036
English
2018
478
2
1649
1659
open
Chehade, B., Carnall, A., Shanks, T., Diener, C., Fumagalli, M., Findlay, J., et al. (2018). Two more, bright, z > 6 quasars from VST ATLAS and WISE. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 478(2), 1649-1659 [10.1093/mnras/sty690].
File in questo prodotto:
File Dimensione Formato  
sty690.pdf

accesso aperto

Tipologia di allegato: Publisher’s Version (Version of Record, VoR)
Dimensione 1.19 MB
Formato Adobe PDF
1.19 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/259353
Citazioni
  • Scopus 33
  • ???jsp.display-item.citation.isi??? 32
Social impact