Report
Evidence of Ultra-faint Radio Frequency Interference in Deep 21~cm Epoch of Reionization Power Spectra with the Murchison Widefield Array
| العنوان: | Evidence of Ultra-faint Radio Frequency Interference in Deep 21~cm Epoch of Reionization Power Spectra with the Murchison Widefield Array |
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| المؤلفون: | Wilensky, Michael J., Morales, Miguel F., Hazelton, Bryna J., Star, Pyxie L., Barry, Nichole, Byrne, Ruby, Jordan, C. H., Jacobs, Daniel C., Pober, Jonathan C., Trott, C. M. |
| المصدر: | The Astrophysical Journal, 2023, Volume 957, Number 2, p. 78 |
| سنة النشر: | 2023 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics |
| الوصف: | We present deep upper limits from the 2014 Murchison Widefield Array (MWA) Phase I observing season, with a particular emphasis on identifying the spectral fingerprints of extremely faint radio frequency interference (RFI) contamination in the 21~cm power spectra (PS). After meticulous RFI excision involving a combination of the \textsc{SSINS} RFI flagger and a series of PS-based jackknife tests, our lowest upper limit on the Epoch of Reionization (EoR) 21~cm PS signal is $\Delta^2 \leq 1.61\cdot10^4 \text{ mK}^2$ at $k=0.258\text{ h Mpc}^{-1}$ at a redshift of 7.1 using 14.7 hours of data. By leveraging our understanding of how even fainter RFI is likely to contaminate the EoR PS, we are able to identify ultra-faint RFI signals in the cylindrical PS. Surprisingly this signature is most obvious in PS formed with less than an hour of data, but is potentially subdominant to other systematics in multiple-hour integrations. Since the total RFI budget in a PS detection is quite strict, this nontrivial integration behavior suggests a need to more realistically model coherently integrated ultra-faint RFI in PS measurements so that its potential contribution to a future detection can be diagnosed. Comment: Update acknowledgements, author metadata, and attach journal doi |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.3847/1538-4357/acffbd |
| URL الوصول: | http://arxiv.org/abs/2310.03851 |
| رقم الانضمام: | edsarx.2310.03851 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.3847/1538-4357/acffbd |
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