Obscured star formation in bright z ≃ 7 Lyman-break galaxies
We present Atacama Large Millimeter/Submillimeter Array observations of the rest-frame far-infrared (FIR) dust continuum emission of six bright Lyman-break galaxies (LBGs) at z ≃ 7. One LBG is detected (5.2σ at peak emission), whilst the others remain individually undetected at the 3σ level. The ave...
| প্রধান লেখক: | , , , , |
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| বিন্যাস: | Journal article |
| প্রকাশিত: |
Oxford University Press
2018
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| _version_ | 1826287805361291264 |
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| author | Bowler, R Bourne, N Dunlop, J McLure, R McLeod, D |
| author_facet | Bowler, R Bourne, N Dunlop, J McLure, R McLeod, D |
| author_sort | Bowler, R |
| collection | OXFORD |
| description | We present Atacama Large Millimeter/Submillimeter Array observations of the rest-frame far-infrared (FIR) dust continuum emission of six bright Lyman-break galaxies (LBGs) at z ≃ 7. One LBG is detected (5.2σ at peak emission), whilst the others remain individually undetected at the 3σ level. The average FIR luminosity of the sample is found to be LFIR≃2×1011L⊙, corresponding to an obscured star formation rate (SFR) that is comparable to that inferred from the unobscured UV emission. In comparison to the infrared excess (IRX=LFIR/LUV)–β relation, our results are consistent with a Calzetti-like attenuation law (assuming a dust temperature of T = 40–50 K). We find a physical offset of 3kpc between the dust continuum emission and the rest-frame UV light probed by Hubble Space Telescope imaging for galaxy ID65666 at z=7.17+0.09−0.06. The offset is suggestive of an inhomogeneous dust distribution, where 75 per cent of the total star formation activity (SFR≃70M⊙/yr) of the galaxy is completely obscured. Our results provide direct evidence that dust obscuration plays a key role in shaping the bright end of the observed rest-frame UV luminosity function at z ≃ 7, in agreement with cosmological galaxy formation simulations. The existence of a heavily obscured component of galaxy ID65666 indicates that dusty star-forming regions, or even entire galaxies, that are ‘UV dark’ are significant even in the z ≃ 7 galaxy population. |
| first_indexed | 2024-03-07T02:04:10Z |
| format | Journal article |
| id | oxford-uuid:9e638f6e-2c36-4f48-98d5-a0b3cc5f19a0 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T02:04:10Z |
| publishDate | 2018 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:9e638f6e-2c36-4f48-98d5-a0b3cc5f19a02022-03-27T00:49:47ZObscured star formation in bright z ≃ 7 Lyman-break galaxiesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:9e638f6e-2c36-4f48-98d5-a0b3cc5f19a0Symplectic Elements at OxfordOxford University Press2018Bowler, RBourne, NDunlop, JMcLure, RMcLeod, DWe present Atacama Large Millimeter/Submillimeter Array observations of the rest-frame far-infrared (FIR) dust continuum emission of six bright Lyman-break galaxies (LBGs) at z ≃ 7. One LBG is detected (5.2σ at peak emission), whilst the others remain individually undetected at the 3σ level. The average FIR luminosity of the sample is found to be LFIR≃2×1011L⊙, corresponding to an obscured star formation rate (SFR) that is comparable to that inferred from the unobscured UV emission. In comparison to the infrared excess (IRX=LFIR/LUV)–β relation, our results are consistent with a Calzetti-like attenuation law (assuming a dust temperature of T = 40–50 K). We find a physical offset of 3kpc between the dust continuum emission and the rest-frame UV light probed by Hubble Space Telescope imaging for galaxy ID65666 at z=7.17+0.09−0.06. The offset is suggestive of an inhomogeneous dust distribution, where 75 per cent of the total star formation activity (SFR≃70M⊙/yr) of the galaxy is completely obscured. Our results provide direct evidence that dust obscuration plays a key role in shaping the bright end of the observed rest-frame UV luminosity function at z ≃ 7, in agreement with cosmological galaxy formation simulations. The existence of a heavily obscured component of galaxy ID65666 indicates that dusty star-forming regions, or even entire galaxies, that are ‘UV dark’ are significant even in the z ≃ 7 galaxy population. |
| spellingShingle | Bowler, R Bourne, N Dunlop, J McLure, R McLeod, D Obscured star formation in bright z ≃ 7 Lyman-break galaxies |
| title | Obscured star formation in bright z ≃ 7 Lyman-break galaxies |
| title_full | Obscured star formation in bright z ≃ 7 Lyman-break galaxies |
| title_fullStr | Obscured star formation in bright z ≃ 7 Lyman-break galaxies |
| title_full_unstemmed | Obscured star formation in bright z ≃ 7 Lyman-break galaxies |
| title_short | Obscured star formation in bright z ≃ 7 Lyman-break galaxies |
| title_sort | obscured star formation in bright z ≃ 7 lyman break galaxies |
| work_keys_str_mv | AT bowlerr obscuredstarformationinbrightz7lymanbreakgalaxies AT bournen obscuredstarformationinbrightz7lymanbreakgalaxies AT dunlopj obscuredstarformationinbrightz7lymanbreakgalaxies AT mclurer obscuredstarformationinbrightz7lymanbreakgalaxies AT mcleodd obscuredstarformationinbrightz7lymanbreakgalaxies |