Spectroscopy of z similar to 7 candidate galaxies: using Lyman alpha to constrain the neutral fraction of hydrogen in the high-redshift universe
Following our previous spectroscopic observations of z > 7 galaxies with Gemini/Gemini Near Infra-Red Spectrograph (GNIRS) and Very Large Telescope (VLT)/XSHOOTER, which targeted a total of eight objects,we present here our results froma deeper and largerVLT/FOcal Reducer and Spectrograph (FO...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Language: | English |
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Oxford University Press
2014
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| _version_ | 1797092192662061056 |
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| author | Caruana, J Bunker, A Wilkins, S Stanway, E Lorenzoni, S Jarvis, M Ebert, H |
| author_facet | Caruana, J Bunker, A Wilkins, S Stanway, E Lorenzoni, S Jarvis, M Ebert, H |
| author_sort | Caruana, J |
| collection | OXFORD |
| description | Following our previous spectroscopic observations of z > 7 galaxies with Gemini/Gemini Near Infra-Red Spectrograph (GNIRS) and Very Large Telescope (VLT)/XSHOOTER, which targeted a total of eight objects,we present here our results froma deeper and largerVLT/FOcal Reducer and Spectrograph (FORS2) spectroscopic sample of Wide Field Camera 3 selected z>7 candidate galaxies.With our FORS2 setup we cover the 737-1070 nm wavelength range, enabling a search for Lyman α in the redshift range spanning 5.06-7.80. We target 22 z-band dropouts and nd no evidence of Lyman α emission, with the exception of a tentative detection (<5σ, which is our adopted criterion for a secure detection) for one object. The upper limits on Lyman α ux and the broad-band magnitudes are used to constrain the rest-frame equivalent widths for this line emission. We analyse our FORS2 observations in combination with our previous GNIRS and XSHOOTER observations, and suggest that a simple model where the fraction of high rest-frame equivalent width emitters follows the trend seen at z = 3-6.5is inconsistent with our non-detections at z ~ 7.8 at the 96 per cent condence level. This may indicate that a signicant neutral HI fraction in the intergalactic medium suppresses Lyman α, with an estimated neutral fraction χHI ~ 0.5, in agreement with other estimates. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. |
| first_indexed | 2024-03-07T03:42:39Z |
| format | Journal article |
| id | oxford-uuid:be6da938-4222-4096-a29e-982d6982fa17 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T03:42:39Z |
| publishDate | 2014 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:be6da938-4222-4096-a29e-982d6982fa172022-03-27T05:39:20ZSpectroscopy of z similar to 7 candidate galaxies: using Lyman alpha to constrain the neutral fraction of hydrogen in the high-redshift universeJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:be6da938-4222-4096-a29e-982d6982fa17EnglishSymplectic Elements at OxfordOxford University Press2014Caruana, JBunker, AWilkins, SStanway, ELorenzoni, SJarvis, MEbert, HFollowing our previous spectroscopic observations of z > 7 galaxies with Gemini/Gemini Near Infra-Red Spectrograph (GNIRS) and Very Large Telescope (VLT)/XSHOOTER, which targeted a total of eight objects,we present here our results froma deeper and largerVLT/FOcal Reducer and Spectrograph (FORS2) spectroscopic sample of Wide Field Camera 3 selected z>7 candidate galaxies.With our FORS2 setup we cover the 737-1070 nm wavelength range, enabling a search for Lyman α in the redshift range spanning 5.06-7.80. We target 22 z-band dropouts and nd no evidence of Lyman α emission, with the exception of a tentative detection (<5σ, which is our adopted criterion for a secure detection) for one object. The upper limits on Lyman α ux and the broad-band magnitudes are used to constrain the rest-frame equivalent widths for this line emission. We analyse our FORS2 observations in combination with our previous GNIRS and XSHOOTER observations, and suggest that a simple model where the fraction of high rest-frame equivalent width emitters follows the trend seen at z = 3-6.5is inconsistent with our non-detections at z ~ 7.8 at the 96 per cent condence level. This may indicate that a signicant neutral HI fraction in the intergalactic medium suppresses Lyman α, with an estimated neutral fraction χHI ~ 0.5, in agreement with other estimates. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. |
| spellingShingle | Caruana, J Bunker, A Wilkins, S Stanway, E Lorenzoni, S Jarvis, M Ebert, H Spectroscopy of z similar to 7 candidate galaxies: using Lyman alpha to constrain the neutral fraction of hydrogen in the high-redshift universe |
| title | Spectroscopy of z similar to 7 candidate galaxies: using Lyman alpha to constrain the neutral fraction of hydrogen in the high-redshift universe |
| title_full | Spectroscopy of z similar to 7 candidate galaxies: using Lyman alpha to constrain the neutral fraction of hydrogen in the high-redshift universe |
| title_fullStr | Spectroscopy of z similar to 7 candidate galaxies: using Lyman alpha to constrain the neutral fraction of hydrogen in the high-redshift universe |
| title_full_unstemmed | Spectroscopy of z similar to 7 candidate galaxies: using Lyman alpha to constrain the neutral fraction of hydrogen in the high-redshift universe |
| title_short | Spectroscopy of z similar to 7 candidate galaxies: using Lyman alpha to constrain the neutral fraction of hydrogen in the high-redshift universe |
| title_sort | spectroscopy of z similar to 7 candidate galaxies using lyman alpha to constrain the neutral fraction of hydrogen in the high redshift universe |
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