Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum
The detection of the Epoch of Reionization (EoR) delay power spectrum using a 'foreground avoidance method' highly depends on the instrument chromaticity. The systematic effects induced by the radio telescope spread the foreground signal in the delay domain, which contaminates the EoR wind...
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| Format: | Article |
| Language: | English |
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Oxford University Press (OUP)
2022
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| Online Access: | https://hdl.handle.net/1721.1/141907 |
| _version_ | 1811003591745339392 |
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| author | Hewitt, Jacqueline N |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Hewitt, Jacqueline N |
| author_sort | Hewitt, Jacqueline N |
| collection | MIT |
| description | The detection of the Epoch of Reionization (EoR) delay power spectrum using a 'foreground avoidance method' highly depends on the instrument chromaticity. The systematic effects induced by the radio telescope spread the foreground signal in the delay domain, which contaminates the EoR window theoretically observable. Applied to the Hydrogen Epoch of Reionization Array (HERA), this paper combines detailed electromagnetic and electrical simulations in order to model the chromatic effects of the instrument, and quantify its frequency and time responses. In particular, the effects of the analogue receiver, transmission cables, and mutual coupling are included. These simulations are able to accurately predict the intensity of the reflections occurring in the 150-m cable which links the antenna to the backend. They also show that electromagnetic waves can propagate from one dish to another one through large sections of the array due to mutual coupling. The simulated system time response is attenuated by a factor 104 after a characteristic delay which depends on the size of the array and on the antenna position. Ultimately, the system response is attenuated by a factor 105 after 1400 ns because of the reflections in the cable, which corresponds to characterizable ka-modes above 0.7 $h\,\,\rm {Mpc}^{-1}$ at 150 MHz. Thus, this new study shows that the detection of the EoR signal with HERA Phase I will be more challenging than expected. On the other hand, it improves our understanding of the telescope, which is essential to mitigate the instrument chromaticity. |
| first_indexed | 2024-09-23T16:06:52Z |
| format | Article |
| id | mit-1721.1/141907 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T16:06:52Z |
| publishDate | 2022 |
| publisher | Oxford University Press (OUP) |
| record_format | dspace |
| spelling | mit-1721.1/1419072023-02-14T20:02:34Z Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum Hewitt, Jacqueline N Massachusetts Institute of Technology. Department of Physics The detection of the Epoch of Reionization (EoR) delay power spectrum using a 'foreground avoidance method' highly depends on the instrument chromaticity. The systematic effects induced by the radio telescope spread the foreground signal in the delay domain, which contaminates the EoR window theoretically observable. Applied to the Hydrogen Epoch of Reionization Array (HERA), this paper combines detailed electromagnetic and electrical simulations in order to model the chromatic effects of the instrument, and quantify its frequency and time responses. In particular, the effects of the analogue receiver, transmission cables, and mutual coupling are included. These simulations are able to accurately predict the intensity of the reflections occurring in the 150-m cable which links the antenna to the backend. They also show that electromagnetic waves can propagate from one dish to another one through large sections of the array due to mutual coupling. The simulated system time response is attenuated by a factor 104 after a characteristic delay which depends on the size of the array and on the antenna position. Ultimately, the system response is attenuated by a factor 105 after 1400 ns because of the reflections in the cable, which corresponds to characterizable ka-modes above 0.7 $h\,\,\rm {Mpc}^{-1}$ at 150 MHz. Thus, this new study shows that the detection of the EoR signal with HERA Phase I will be more challenging than expected. On the other hand, it improves our understanding of the telescope, which is essential to mitigate the instrument chromaticity. 2022-04-15T13:07:57Z 2022-04-15T13:07:57Z 2020 2022-04-15T12:44:38Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/141907 Hewitt, Jacqueline N. 2020. "Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum." Monthly Notices of the Royal Astronomical Society, 500 (1). en 10.1093/MNRAS/STAA3268 Monthly Notices of the Royal Astronomical Society Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Oxford University Press (OUP) arXiv |
| spellingShingle | Hewitt, Jacqueline N Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum |
| title | Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum |
| title_full | Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum |
| title_fullStr | Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum |
| title_full_unstemmed | Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum |
| title_short | Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum |
| title_sort | understanding the hera phase i receiver system with simulations and its impact on the detectability of the eor delay power spectrum |
| url | https://hdl.handle.net/1721.1/141907 |
| work_keys_str_mv | AT hewittjacquelinen understandingtheheraphaseireceiversystemwithsimulationsanditsimpactonthedetectabilityoftheeordelaypowerspectrum |