Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Study of systematics effects on the Cross Power Spectrum of 21 cm Line
  and Cosmic Microwave Background using Murchison Widefield Array Data   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.

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The categories of this paper are: q-bio
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
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The categories of this paper are: econ
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
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The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
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The categories of this paper are: q-fin
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an