The impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments
Predictions for the ability of 21 cm interferometric experiments to discriminate Epoch of Reionization (EoR) signal models are typically limited by the simplicity of data models, whereby foreground signals and characteristics of the instrument are often simplified or neglected. To move toward more r...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Language: | English |
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IOP PUBLISHING LTD
2020
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| Subjects: | |
| Online Access: | http://purl.org/au-research/grants/arc/CE170100013 http://hdl.handle.net/20.500.11937/90037 |
| _version_ | 1848765316439474176 |
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| author | Nasirudin, Ainulnabilah Murray, Steven Trott, Cathryn Greig, B. Joseph, Ronniy C. Power, C. |
| author_facet | Nasirudin, Ainulnabilah Murray, Steven Trott, Cathryn Greig, B. Joseph, Ronniy C. Power, C. |
| author_sort | Nasirudin, Ainulnabilah |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Predictions for the ability of 21 cm interferometric experiments to discriminate Epoch of Reionization (EoR) signal models are typically limited by the simplicity of data models, whereby foreground signals and characteristics of the instrument are often simplified or neglected. To move toward more realistic scenarios, we explore the effects of applying more realistic foreground and instrument models to the 21 cm signal, as well as the ability to estimate astrophysical parameters with these additional complexities. We use a highly optimized version of 21cmFAST, integrated into 21cmMC, to generate lightcones of the brightness temperature fluctuation for Bayesian parameter estimation. We include a statistical point-source foreground model and an instrument model based on the Murchison Widefield Array scaled in observation time to have an effective sensitivity similar to the future Square Kilometre Array. We also extend the current likelihood prescription to account for the presence of beam convolution and foregrounds, the two-dimensional power spectrum (PS), and the correlation of PS modes. We use frequency bands between 150 and 180 MHz to constrain the ionizing efficiency (ζ), the minimum virial temperature of halos (), the soft X-ray emissivity per unit star formation rate (SFR) (L X/SFR), and the X-ray energy threshold (E 0). We find that the inclusion of realistic foregrounds and instrumental components biases the parameter constraints, due to unaccounted for cross-power between the EoR signal, foregrounds, and thermal noise. This causes estimates of ζ to be biased by up to 5σ, but the estimates of T vir, L X/SFR and E 0 remain unaffected and are all within 1σ. |
| first_indexed | 2025-11-14T11:33:19Z |
| format | Journal Article |
| id | curtin-20.500.11937-90037 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:33:19Z |
| publishDate | 2020 |
| publisher | IOP PUBLISHING LTD |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-900372023-02-08T01:13:04Z The impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments Nasirudin, Ainulnabilah Murray, Steven Trott, Cathryn Greig, B. Joseph, Ronniy C. Power, C. Science & Technology Physical Sciences Astronomy & Astrophysics Reionization Cosmology Large-scale structure of the universe Astronomical instrumentation COSMIC DAWN ASTROPHYSICS SIMULATIONS COSMOLOGY PARAMETER 21CMMC Predictions for the ability of 21 cm interferometric experiments to discriminate Epoch of Reionization (EoR) signal models are typically limited by the simplicity of data models, whereby foreground signals and characteristics of the instrument are often simplified or neglected. To move toward more realistic scenarios, we explore the effects of applying more realistic foreground and instrument models to the 21 cm signal, as well as the ability to estimate astrophysical parameters with these additional complexities. We use a highly optimized version of 21cmFAST, integrated into 21cmMC, to generate lightcones of the brightness temperature fluctuation for Bayesian parameter estimation. We include a statistical point-source foreground model and an instrument model based on the Murchison Widefield Array scaled in observation time to have an effective sensitivity similar to the future Square Kilometre Array. We also extend the current likelihood prescription to account for the presence of beam convolution and foregrounds, the two-dimensional power spectrum (PS), and the correlation of PS modes. We use frequency bands between 150 and 180 MHz to constrain the ionizing efficiency (ζ), the minimum virial temperature of halos (), the soft X-ray emissivity per unit star formation rate (SFR) (L X/SFR), and the X-ray energy threshold (E 0). We find that the inclusion of realistic foregrounds and instrumental components biases the parameter constraints, due to unaccounted for cross-power between the EoR signal, foregrounds, and thermal noise. This causes estimates of ζ to be biased by up to 5σ, but the estimates of T vir, L X/SFR and E 0 remain unaffected and are all within 1σ. 2020 Journal Article http://hdl.handle.net/20.500.11937/90037 10.3847/1538-4357/ab8003 English http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/FT180100321 http://creativecommons.org/licenses/by/4.0/ IOP PUBLISHING LTD fulltext |
| spellingShingle | Science & Technology Physical Sciences Astronomy & Astrophysics Reionization Cosmology Large-scale structure of the universe Astronomical instrumentation COSMIC DAWN ASTROPHYSICS SIMULATIONS COSMOLOGY PARAMETER 21CMMC Nasirudin, Ainulnabilah Murray, Steven Trott, Cathryn Greig, B. Joseph, Ronniy C. Power, C. The impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments |
| title | The impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments |
| title_full | The impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments |
| title_fullStr | The impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments |
| title_full_unstemmed | The impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments |
| title_short | The impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments |
| title_sort | impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments |
| topic | Science & Technology Physical Sciences Astronomy & Astrophysics Reionization Cosmology Large-scale structure of the universe Astronomical instrumentation COSMIC DAWN ASTROPHYSICS SIMULATIONS COSMOLOGY PARAMETER 21CMMC |
| url | http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/CE170100013 http://hdl.handle.net/20.500.11937/90037 |