Аннотация
We present limits on the 21cm power spectrum from the Epoch of Reionization
(EoR) using data from the 64 antenna configuration of the Donald C. Backer
Precision Array for Probing the Epoch of Reionization (PAPER) analyzed through
a power spectrum pipeline independent from previous PAPER analyses. Previously
reported results from PAPER have been found to contain significant signal loss
(Cheng et al. 2018, arxiv:1810.05175). Several lossy steps from previous PAPER
pipelines have not been included in this analysis, namely: delay-based
foreground filtering, optimal fringe-rate filtering, and empirical
covariance-based estimators. Steps which remain in common with previous
analyses include redundant calibration and local sidereal time (LST) binning.
The power spectra reported here are effectively the result of applying a linear
Fourier transform analysis to the calibrated, LST binned data. This analysis
also uses more data than previous publications, including the complete
available redshift range of $z 7.5$ to $11$. In previous PAPER analyses,
many power spectrum measurements were found to be detections of noncosmological
power at levels of significance ranging from two to hundreds of times the
theoretical noise. Here, excess power is examined using redundancy between
baselines and power spectrum jackknives. The upper limits we find on the 21cm
power spectrum from reionization are ($1500$ mK)$^2$, ($1900$ mK)$^2$,
($280$ mK)$^2$, ($200$ mK)$^2$, ($380$ mK)$^2$, ($300$ mK)$^2$ at
redshifts $z=10.87,\ 9.93,\ 8.68,\ 8.37,\ 8.13,$ and $7.48$, respectively. For
reasons described in Cheng et al. 2018 (arxiv:1810.05175), these limits
supersede all previous PAPER results (Ali et al. 2018, arxiv:1502.06016).
Пользователи данного ресурса
Пожалуйста,
войдите в систему, чтобы принять участие в дискуссии (добавить собственные рецензию, или комментарий)