Characterizing the evolving K -band luminosity function using the UltraVISTA, CANDELS and HUDF surveys
We present the results of a new study of the K-band galaxy luminosity function (KLF) at redshifts z ≤ 3.75, based on a nested combination of the UltraVISTA, Cosmic Assembly Nearinfrared Deep Legacy Extragalactic Survey and HUDF surveys. The large dynamic range in luminosity spanned by this new data...
| Main Authors: | , , , , , , , |
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| Format: | Journal article |
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Oxford University Press
2016
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| _version_ | 1797093770087366656 |
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| author | Mortlock, A McLure, R Bowler, R McLeod, D Mármol-Queraltó, E Parsa, S Dunlop, J Bruce, V |
| author_facet | Mortlock, A McLure, R Bowler, R McLeod, D Mármol-Queraltó, E Parsa, S Dunlop, J Bruce, V |
| author_sort | Mortlock, A |
| collection | OXFORD |
| description | We present the results of a new study of the K-band galaxy luminosity function (KLF) at redshifts z ≤ 3.75, based on a nested combination of the UltraVISTA, Cosmic Assembly Nearinfrared Deep Legacy Extragalactic Survey and HUDF surveys. The large dynamic range in luminosity spanned by this new data set (3-4 dex over the full redshift range) is sufficient to clearly demonstrate for the first time that the faint-end slope of the KLF at z ≥ 0.25 is relatively steep (-1.3 ≤ α ≤ -1.5 for a single Schechter function), in good agreement with recent theoretical and phenomenological models. Moreover, based on our new data set, we find that a double Schechter function provides a significantly improved description of the KLF at z ≤ 2. At redshifts z ≥ 0.25, the evolution of the KLF is remarkably smooth, with little or no evolution evident at faint (MK* ≥-20.5) or bright magnitudes (MK* ≤-24.5). Instead, the KLF is seen to evolve rapidly at intermediatemagnitudes, with the number density of galaxies at MK* ≃-23 dropping by a factor of ≃5 over the redshift interval 0.25 ≤ z ≥ 3.75. Motivated by this, we explore a simple description of the evolving KLF based on a double Schechter function with fixed faint-end slopes (α1= -0.5, α2= -1.5) and a shared characteristic magnitude (MK*). According to this parametrization, the normalization of the component which dominates the faint end of the KLF remains approximately constant, with φ2decreasing by only a factor of ≃2 between z ≃0 and 3.25. In contrast, the component which dominates the bright end of the KLF at low redshifts evolves dramatically, becoming essentially negligible by z ≃3. Finally, we note that within this parametrization, the observed evolution of MK*between z ≃0 and 3.25 is entirely consistent with MK*corresponding to a constant stellar mass of M≃5 × 1010 M⊙at all redshifts. |
| first_indexed | 2024-03-07T04:05:02Z |
| format | Journal article |
| id | oxford-uuid:c5db3f0e-5639-46bf-8822-7dae26da4afb |
| institution | University of Oxford |
| last_indexed | 2024-03-07T04:05:02Z |
| publishDate | 2016 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:c5db3f0e-5639-46bf-8822-7dae26da4afb2022-03-27T06:34:08ZCharacterizing the evolving K -band luminosity function using the UltraVISTA, CANDELS and HUDF surveysJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:c5db3f0e-5639-46bf-8822-7dae26da4afbSymplectic Elements at OxfordOxford University Press2016Mortlock, AMcLure, RBowler, RMcLeod, DMármol-Queraltó, EParsa, SDunlop, JBruce, VWe present the results of a new study of the K-band galaxy luminosity function (KLF) at redshifts z ≤ 3.75, based on a nested combination of the UltraVISTA, Cosmic Assembly Nearinfrared Deep Legacy Extragalactic Survey and HUDF surveys. The large dynamic range in luminosity spanned by this new data set (3-4 dex over the full redshift range) is sufficient to clearly demonstrate for the first time that the faint-end slope of the KLF at z ≥ 0.25 is relatively steep (-1.3 ≤ α ≤ -1.5 for a single Schechter function), in good agreement with recent theoretical and phenomenological models. Moreover, based on our new data set, we find that a double Schechter function provides a significantly improved description of the KLF at z ≤ 2. At redshifts z ≥ 0.25, the evolution of the KLF is remarkably smooth, with little or no evolution evident at faint (MK* ≥-20.5) or bright magnitudes (MK* ≤-24.5). Instead, the KLF is seen to evolve rapidly at intermediatemagnitudes, with the number density of galaxies at MK* ≃-23 dropping by a factor of ≃5 over the redshift interval 0.25 ≤ z ≥ 3.75. Motivated by this, we explore a simple description of the evolving KLF based on a double Schechter function with fixed faint-end slopes (α1= -0.5, α2= -1.5) and a shared characteristic magnitude (MK*). According to this parametrization, the normalization of the component which dominates the faint end of the KLF remains approximately constant, with φ2decreasing by only a factor of ≃2 between z ≃0 and 3.25. In contrast, the component which dominates the bright end of the KLF at low redshifts evolves dramatically, becoming essentially negligible by z ≃3. Finally, we note that within this parametrization, the observed evolution of MK*between z ≃0 and 3.25 is entirely consistent with MK*corresponding to a constant stellar mass of M≃5 × 1010 M⊙at all redshifts. |
| spellingShingle | Mortlock, A McLure, R Bowler, R McLeod, D Mármol-Queraltó, E Parsa, S Dunlop, J Bruce, V Characterizing the evolving K -band luminosity function using the UltraVISTA, CANDELS and HUDF surveys |
| title | Characterizing the evolving K -band luminosity function using the UltraVISTA, CANDELS and HUDF surveys |
| title_full | Characterizing the evolving K -band luminosity function using the UltraVISTA, CANDELS and HUDF surveys |
| title_fullStr | Characterizing the evolving K -band luminosity function using the UltraVISTA, CANDELS and HUDF surveys |
| title_full_unstemmed | Characterizing the evolving K -band luminosity function using the UltraVISTA, CANDELS and HUDF surveys |
| title_short | Characterizing the evolving K -band luminosity function using the UltraVISTA, CANDELS and HUDF surveys |
| title_sort | characterizing the evolving k band luminosity function using the ultravista candels and hudf surveys |
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