Imaging of SDSS z > 6 quasar fields: Gravitational lensing, companion galaxies, and the host dark matter halos

We have undertaken deep optical imaging observations of three 6.2 < z < 6.5 quasar fields in the i′ and z′ filters. These data are used to search for foreground galaxies that are gravitationally lensing the quasars and distant galaxies physically associated with the quasars. Foreground...

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Hauptverfasser: Willott, C, Percival, W, Mclure, R, Crampton, D, Hutchings, J, Jarvis, M, Sawicki, M, Simard, L
Format: Journal article
Sprache:English
Veröffentlicht: Institute of Physics Publishing 2005
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author Willott, C
Percival, W
Mclure, R
Crampton, D
Hutchings, J
Jarvis, M
Sawicki, M
Simard, L
author_facet Willott, C
Percival, W
Mclure, R
Crampton, D
Hutchings, J
Jarvis, M
Sawicki, M
Simard, L
author_sort Willott, C
collection OXFORD
description We have undertaken deep optical imaging observations of three 6.2 < z < 6.5 quasar fields in the i′ and z′ filters. These data are used to search for foreground galaxies that are gravitationally lensing the quasars and distant galaxies physically associated with the quasars. Foreground galaxies are found closer than 5″ to the lines of sight of two of the three quasars. However, the faintness of these galaxies suggests that they have fairly low masses and provide only weak magnifications (μ ≲1.1). No convincing galaxies physically associated with the quasars are found, and the number of i′-band dropouts is consistent with that found in random fields. We consider the expected dark matter halo masses that host these quasars under the assumption that a correlation between black hole mass and dark matter halo mass exists. We show that the steepness of the high-mass tail of the halo mass function at this redshift, combined with realistic amounts of scatter in this correlation, leads to expected halo masses substantially lower than previously believed. This analysis can explain the lack of companion galaxies found here and the low dynamical mass recently published for one of the quasars. © 2005. The American Astronomical Society. All rights reserved.
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spelling oxford-uuid:7a1425c6-c2e9-430c-9c0f-30908bdbb10a2022-03-26T20:41:34ZImaging of SDSS z > 6 quasar fields: Gravitational lensing, companion galaxies, and the host dark matter halosJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:7a1425c6-c2e9-430c-9c0f-30908bdbb10aEnglishSymplectic Elements at OxfordInstitute of Physics Publishing2005Willott, CPercival, WMclure, RCrampton, DHutchings, JJarvis, MSawicki, MSimard, LWe have undertaken deep optical imaging observations of three 6.2 < z < 6.5 quasar fields in the i′ and z′ filters. These data are used to search for foreground galaxies that are gravitationally lensing the quasars and distant galaxies physically associated with the quasars. Foreground galaxies are found closer than 5″ to the lines of sight of two of the three quasars. However, the faintness of these galaxies suggests that they have fairly low masses and provide only weak magnifications (μ ≲1.1). No convincing galaxies physically associated with the quasars are found, and the number of i′-band dropouts is consistent with that found in random fields. We consider the expected dark matter halo masses that host these quasars under the assumption that a correlation between black hole mass and dark matter halo mass exists. We show that the steepness of the high-mass tail of the halo mass function at this redshift, combined with realistic amounts of scatter in this correlation, leads to expected halo masses substantially lower than previously believed. This analysis can explain the lack of companion galaxies found here and the low dynamical mass recently published for one of the quasars. © 2005. The American Astronomical Society. All rights reserved.
spellingShingle Willott, C
Percival, W
Mclure, R
Crampton, D
Hutchings, J
Jarvis, M
Sawicki, M
Simard, L
Imaging of SDSS z > 6 quasar fields: Gravitational lensing, companion galaxies, and the host dark matter halos
title Imaging of SDSS z > 6 quasar fields: Gravitational lensing, companion galaxies, and the host dark matter halos
title_full Imaging of SDSS z > 6 quasar fields: Gravitational lensing, companion galaxies, and the host dark matter halos
title_fullStr Imaging of SDSS z > 6 quasar fields: Gravitational lensing, companion galaxies, and the host dark matter halos
title_full_unstemmed Imaging of SDSS z > 6 quasar fields: Gravitational lensing, companion galaxies, and the host dark matter halos
title_short Imaging of SDSS z > 6 quasar fields: Gravitational lensing, companion galaxies, and the host dark matter halos
title_sort imaging of sdss z gt 6 quasar fields gravitational lensing companion galaxies and the host dark matter halos
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