Exploring 21 cm-Lya Emitter Synergies for SKA
We study the signatures of reionization and ionizing properties of early galaxies in the cross-correlations between the 21 cm emission from the spin-flip transition of neutral hydrogen (H i) and the underlying galaxy population. In particular, we focus on a sub-population of galaxies visible as Lyα...
| Main Authors: | , , , |
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| Format: | Journal Article |
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Institute of Physics Publishing
2017
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| Online Access: | http://purl.org/au-research/grants/arc/DE140100316 http://hdl.handle.net/20.500.11937/51841 |
| _version_ | 1848758784921436160 |
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| author | Hutter, A. Dayal, P. Müller, V. Trott, Cathryn |
| author_facet | Hutter, A. Dayal, P. Müller, V. Trott, Cathryn |
| author_sort | Hutter, A. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We study the signatures of reionization and ionizing properties of early galaxies in the cross-correlations between the 21 cm emission from the spin-flip transition of neutral hydrogen (H i) and the underlying galaxy population. In particular, we focus on a sub-population of galaxies visible as Lyα Emitters (LAEs). With both observables simultaneously derived from a z ≃ 6.6 hydrodynamical simulation (GADGET-2) snapshot post-processed with a radiative transfer code (pCRASH) and a dust model, we perform a parameter study and aim to constrain both the average intergalactic medium (IGM) ionization state (1 – {XHI}) and the reionization topology (outside-in versus inside-out). We find that, in our model, LAEs occupy the densest and most-ionized regions resulting in a very strong anti-correlation between the LAEs and the 21 cm emission. A 1000 hr Square Kilometer Array (SKA)-LOW1—Subaru Hyper Suprime-Cam experiment can provide constraints on (XHI), allowing us to distinguish between IGM ionization levels of 50%, 25%, 10%, and fully ionized at scales r <~ 10 comoving Mpc (assuming foreground avoidance for SKA). Our results support the inside-out reionization scenario where the densest knots (under-dense voids) are ionized first (last) for (XHI) >~ 0.1. Further, 1000 hr SKA-LOW1 observations should be able to confirm the inside-out scenario by detecting a lower 21 cm brightness temperature (by about 2–10 mK) in the densest regions (>~2 arcmin scales) hosting LAEs, compared to lower-density regions devoid of them. © 2017. The American Astronomical Society. All rights reserved. |
| first_indexed | 2025-11-14T09:49:30Z |
| format | Journal Article |
| id | curtin-20.500.11937-51841 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:49:30Z |
| publishDate | 2017 |
| publisher | Institute of Physics Publishing |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-518412022-09-06T04:28:05Z Exploring 21 cm-Lya Emitter Synergies for SKA Hutter, A. Dayal, P. Müller, V. Trott, Cathryn We study the signatures of reionization and ionizing properties of early galaxies in the cross-correlations between the 21 cm emission from the spin-flip transition of neutral hydrogen (H i) and the underlying galaxy population. In particular, we focus on a sub-population of galaxies visible as Lyα Emitters (LAEs). With both observables simultaneously derived from a z ≃ 6.6 hydrodynamical simulation (GADGET-2) snapshot post-processed with a radiative transfer code (pCRASH) and a dust model, we perform a parameter study and aim to constrain both the average intergalactic medium (IGM) ionization state (1 – {XHI}) and the reionization topology (outside-in versus inside-out). We find that, in our model, LAEs occupy the densest and most-ionized regions resulting in a very strong anti-correlation between the LAEs and the 21 cm emission. A 1000 hr Square Kilometer Array (SKA)-LOW1—Subaru Hyper Suprime-Cam experiment can provide constraints on (XHI), allowing us to distinguish between IGM ionization levels of 50%, 25%, 10%, and fully ionized at scales r <~ 10 comoving Mpc (assuming foreground avoidance for SKA). Our results support the inside-out reionization scenario where the densest knots (under-dense voids) are ionized first (last) for (XHI) >~ 0.1. Further, 1000 hr SKA-LOW1 observations should be able to confirm the inside-out scenario by detecting a lower 21 cm brightness temperature (by about 2–10 mK) in the densest regions (>~2 arcmin scales) hosting LAEs, compared to lower-density regions devoid of them. © 2017. The American Astronomical Society. All rights reserved. 2017 Journal Article http://hdl.handle.net/20.500.11937/51841 10.3847/1538-4357/836/2/176 http://purl.org/au-research/grants/arc/DE140100316 Institute of Physics Publishing restricted |
| spellingShingle | Hutter, A. Dayal, P. Müller, V. Trott, Cathryn Exploring 21 cm-Lya Emitter Synergies for SKA |
| title | Exploring 21 cm-Lya Emitter Synergies for SKA |
| title_full | Exploring 21 cm-Lya Emitter Synergies for SKA |
| title_fullStr | Exploring 21 cm-Lya Emitter Synergies for SKA |
| title_full_unstemmed | Exploring 21 cm-Lya Emitter Synergies for SKA |
| title_short | Exploring 21 cm-Lya Emitter Synergies for SKA |
| title_sort | exploring 21 cm-lya emitter synergies for ska |
| url | http://purl.org/au-research/grants/arc/DE140100316 http://hdl.handle.net/20.500.11937/51841 |