Study of systematics effects on the cross power spectrum of 21 cm line and cosmic microwave background using Murchison Widefield Array data
Autor: | Keitaro Takahashi, B. Pindor, Shintaro Yoshiura, Hiroyuki Tashiro, Kiyotomo Ichiki, Cathryn M. Trott |
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Rok vydání: | 2018 |
Předmět: |
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
media_common.quotation_subject Cosmic microwave background Cosmic background radiation FOS: Physical sciences Murchison Widefield Array Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences symbols.namesake 0103 physical sciences Planck 010303 astronomy & astrophysics Reionization Astrophysics::Galaxy Astrophysics media_common Physics 010308 nuclear & particles physics Astrophysics::Instrumentation and Methods for Astrophysics Astronomy and Astrophysics 13. Climate action Space and Planetary Science Sky Dark Ages symbols Hydrogen line Astrophysics - Cosmology and Nongalactic Astrophysics |
Zdroj: | Monthly Notices of the Royal Astronomical Society. 483:2697-2711 |
ISSN: | 1365-2966 0035-8711 |
Popis: | Observation of the 21cm line signal from neutral hydrogen during the Epoch of Reionization is challenging due to extremely bright Galactic and extragalactic foregrounds and complicated instrumental calibration. A reasonable approach for mitigating these problems is the cross correlation with other observables. In this work, we present the first results of the cross power spectrum (CPS) between radio images observed by the Murchison Widefield Array and the cosmic microwave background (CMB), measured by the Planck experiment. We study the systematics due to the ionospheric activity, the dependence of CPS on group of pointings, and frequency. The resulting CPS is consistent with zero because the error is dominated by the foregrounds in the 21cm observation. Additionally, the variance of the signal indicates the presence of unexpected systematics error at small scales. Furthermore, we reduce the error by one order of magnitude with application of a foreground removal using a polynomial fitting method. Based on the results, we find that the detection of the 21cm-CMB CPS with the MWA Phase I requires more than 99.95% of the foreground signal removed, 2000 hours of deep observation and 50% of the sky fraction coverage. Comment: 15 pages, 16 figures, accepted to MNRAS |
Databáze: | OpenAIRE |
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