Impact of station far sidelobes on EoR/CD power spectra
Stations of dipole antennas for SKA1-Low will comprise 256 elements spread over an area with a diameter of 38 m. We consider the effect of residual unsubtracted sources well outside of the main beam for differing numbers of unique station configurations, in the epoch of reionization (EoR) and the co...
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| Format: | Journal Article |
| Language: | English |
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SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS
2022
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| Online Access: | http://purl.org/au-research/grants/arc/CE170100013 http://hdl.handle.net/20.500.11937/91575 |
| _version_ | 1848765552551526400 |
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| author | Trott, Cathryn |
| author_facet | Trott, Cathryn |
| author_sort | Trott, Cathryn |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Stations of dipole antennas for SKA1-Low will comprise 256 elements spread over an area with a diameter of 38 m. We consider the effect of residual unsubtracted sources well outside of the main beam for differing numbers of unique station configurations, in the epoch of reionization (EoR) and the cosmic dawn (CD), both in simulation and with theoretical considerations. We find that beam sidelobes imprint power that renders the cosmological signal unobservable over a range of scales unless compact sources are subtracted beyond θZ = 30 degrees from zenith, and that station apodization will likely be required to control far sidelobes. An array with Nb = 4 unique station configurations is sufficient to reduce the contamination, with an increase to Nb = 8 showing little improvement. Comparison with an achromatic Airy disk beam model shows that beam sidelobe level is the main contributor to excess power in the EoR window, and beam chromaticity is less relevant. In the EoR, z = 8.5, subtracting sources above 200 mJy out to θZ = 45 deg, will be required to access relevant modes of the power spectrum. |
| first_indexed | 2025-11-14T11:37:04Z |
| format | Journal Article |
| id | curtin-20.500.11937-91575 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:37:04Z |
| publishDate | 2022 |
| publisher | SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-915752023-05-17T04:51:29Z Impact of station far sidelobes on EoR/CD power spectra Trott, Cathryn Science & Technology Technology Physical Sciences Engineering, Aerospace Instruments & Instrumentation Optics Engineering astronomy antennas interferometry REIONIZATION EPOCH LIMITS ARRAY astro-ph.IM astro-ph.IM astro-ph.CO Stations of dipole antennas for SKA1-Low will comprise 256 elements spread over an area with a diameter of 38 m. We consider the effect of residual unsubtracted sources well outside of the main beam for differing numbers of unique station configurations, in the epoch of reionization (EoR) and the cosmic dawn (CD), both in simulation and with theoretical considerations. We find that beam sidelobes imprint power that renders the cosmological signal unobservable over a range of scales unless compact sources are subtracted beyond θZ = 30 degrees from zenith, and that station apodization will likely be required to control far sidelobes. An array with Nb = 4 unique station configurations is sufficient to reduce the contamination, with an increase to Nb = 8 showing little improvement. Comparison with an achromatic Airy disk beam model shows that beam sidelobe level is the main contributor to excess power in the EoR window, and beam chromaticity is less relevant. In the EoR, z = 8.5, subtracting sources above 200 mJy out to θZ = 45 deg, will be required to access relevant modes of the power spectrum. 2022 Journal Article http://hdl.handle.net/20.500.11937/91575 10.1117/1.JATIS.8.1.011011 English http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/FT180100321 SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS fulltext |
| spellingShingle | Science & Technology Technology Physical Sciences Engineering, Aerospace Instruments & Instrumentation Optics Engineering astronomy antennas interferometry REIONIZATION EPOCH LIMITS ARRAY astro-ph.IM astro-ph.IM astro-ph.CO Trott, Cathryn Impact of station far sidelobes on EoR/CD power spectra |
| title | Impact of station far sidelobes on EoR/CD power spectra |
| title_full | Impact of station far sidelobes on EoR/CD power spectra |
| title_fullStr | Impact of station far sidelobes on EoR/CD power spectra |
| title_full_unstemmed | Impact of station far sidelobes on EoR/CD power spectra |
| title_short | Impact of station far sidelobes on EoR/CD power spectra |
| title_sort | impact of station far sidelobes on eor/cd power spectra |
| topic | Science & Technology Technology Physical Sciences Engineering, Aerospace Instruments & Instrumentation Optics Engineering astronomy antennas interferometry REIONIZATION EPOCH LIMITS ARRAY astro-ph.IM astro-ph.IM astro-ph.CO |
| url | http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/CE170100013 http://hdl.handle.net/20.500.11937/91575 |