The bright end of the galaxy luminosity function at z ≃ 7 from the VISTA VIDEO survey
<p>We have conducted a search for <em>z</em> ≃ 7 Lyman-break galaxies over 8.2 deg<sup>2</sup> of near-infrared imaging from the Visible and Infrared Survey Telescope for Astronomy (VISTA) Deep Extragalactic Observations (VID...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
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Oxford University Press
2023
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| _version_ | 1826311707782283264 |
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| author | Varadaraj, RG Bowler, RAA Jarvis, MJ Adams, NJ Haussler, B |
| author_facet | Varadaraj, RG Bowler, RAA Jarvis, MJ Adams, NJ Haussler, B |
| author_sort | Varadaraj, RG |
| collection | OXFORD |
| description | <p>We have conducted a search for <em>z</em> ≃ 7 Lyman-break galaxies over 8.2 deg<sup>2</sup> of near-infrared imaging from the Visible and Infrared Survey Telescope for Astronomy (VISTA) Deep Extragalactic Observations (VIDEO) survey in the <em>XMM–Newton</em>-Large Scale Structure (XMM-LSS) and the <em>Extended Chandra Deep Field</em>-South (ECDF-S) fields. Candidate galaxies were selected from a full photometric redshift analysis down to a <em>Y</em> + <em>J</em> depth of 25.3 (5σ), utilizing deep auxiliary optical and <em>Spitzer</em>/Infrared Array Camera (IRAC) data to remove brown dwarf and red interloper galaxy contaminants. Our final sample consists of 28 candidate galaxies at 6.5 ≤ <em>z</em> ≤ 7.5 with −23.5 ≤ <em>M</em><sub>UV</sub> ≤ −21.6. We derive stellar masses of 9.1 ≤ log<sub>10</sub>(<em>M</em><sub>⋆</sub>/M<sub>⊙</sub>) ≤ 10.9 for the sample, suggesting that these candidates represent some of the most massive galaxies known at this epoch. We measure the rest-frame ultraviolet (UV) luminosity function (LF) at <em>z</em> ≃ 7, confirming previous findings of a gradual decline in number density at the bright end (<em>M</em><sub>UV</sub> < −22) that is well described by a double power law (DPL). We show that quasar contamination in this magnitude range is expected to be minimal, in contrast to conclusions from recent pure-parallel <em>Hubble</em> studies. Our results are up to a factor of 10 lower than previous determinations from optical-only ground-based studies at <em>M</em><sub>UV</sub> ≲ −23. We find that the inclusion of <em>YJHK</em><sub>s</sub> photometry is vital for removing brown dwarf contaminants, and <em>z</em> ≃ 7 samples based on red optical data alone could be highly contaminated (≳50 per cent). In comparison with other robust <em>z</em> > 5 samples, our results further support little evolution in the very bright end of the rest-frame UV LF from <em>z</em> = 5–10, potentially signalling a lack of mass quenching and/or dust obscuration in the most massive galaxies in the first Gyr.</p> |
| first_indexed | 2024-03-07T08:13:40Z |
| format | Journal article |
| id | oxford-uuid:1e61b4b8-336d-40e4-88c7-f4d43163763e |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T08:13:40Z |
| publishDate | 2023 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:1e61b4b8-336d-40e4-88c7-f4d43163763e2023-12-19T06:32:44ZThe bright end of the galaxy luminosity function at z ≃ 7 from the VISTA VIDEO surveyJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1e61b4b8-336d-40e4-88c7-f4d43163763eEnglishSymplectic ElementsOxford University Press2023Varadaraj, RGBowler, RAAJarvis, MJAdams, NJHaussler, B<p>We have conducted a search for <em>z</em> ≃ 7 Lyman-break galaxies over 8.2 deg<sup>2</sup> of near-infrared imaging from the Visible and Infrared Survey Telescope for Astronomy (VISTA) Deep Extragalactic Observations (VIDEO) survey in the <em>XMM–Newton</em>-Large Scale Structure (XMM-LSS) and the <em>Extended Chandra Deep Field</em>-South (ECDF-S) fields. Candidate galaxies were selected from a full photometric redshift analysis down to a <em>Y</em> + <em>J</em> depth of 25.3 (5σ), utilizing deep auxiliary optical and <em>Spitzer</em>/Infrared Array Camera (IRAC) data to remove brown dwarf and red interloper galaxy contaminants. Our final sample consists of 28 candidate galaxies at 6.5 ≤ <em>z</em> ≤ 7.5 with −23.5 ≤ <em>M</em><sub>UV</sub> ≤ −21.6. We derive stellar masses of 9.1 ≤ log<sub>10</sub>(<em>M</em><sub>⋆</sub>/M<sub>⊙</sub>) ≤ 10.9 for the sample, suggesting that these candidates represent some of the most massive galaxies known at this epoch. We measure the rest-frame ultraviolet (UV) luminosity function (LF) at <em>z</em> ≃ 7, confirming previous findings of a gradual decline in number density at the bright end (<em>M</em><sub>UV</sub> < −22) that is well described by a double power law (DPL). We show that quasar contamination in this magnitude range is expected to be minimal, in contrast to conclusions from recent pure-parallel <em>Hubble</em> studies. Our results are up to a factor of 10 lower than previous determinations from optical-only ground-based studies at <em>M</em><sub>UV</sub> ≲ −23. We find that the inclusion of <em>YJHK</em><sub>s</sub> photometry is vital for removing brown dwarf contaminants, and <em>z</em> ≃ 7 samples based on red optical data alone could be highly contaminated (≳50 per cent). In comparison with other robust <em>z</em> > 5 samples, our results further support little evolution in the very bright end of the rest-frame UV LF from <em>z</em> = 5–10, potentially signalling a lack of mass quenching and/or dust obscuration in the most massive galaxies in the first Gyr.</p> |
| spellingShingle | Varadaraj, RG Bowler, RAA Jarvis, MJ Adams, NJ Haussler, B The bright end of the galaxy luminosity function at z ≃ 7 from the VISTA VIDEO survey |
| title | The bright end of the galaxy luminosity function at z ≃ 7 from the VISTA VIDEO survey |
| title_full | The bright end of the galaxy luminosity function at z ≃ 7 from the VISTA VIDEO survey |
| title_fullStr | The bright end of the galaxy luminosity function at z ≃ 7 from the VISTA VIDEO survey |
| title_full_unstemmed | The bright end of the galaxy luminosity function at z ≃ 7 from the VISTA VIDEO survey |
| title_short | The bright end of the galaxy luminosity function at z ≃ 7 from the VISTA VIDEO survey |
| title_sort | bright end of the galaxy luminosity function at z ≃ 7 from the vista video survey |
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