Angular power spectra of 610 MHz radio halos show excess power-law fluctuations only in Abell 2744, requiring multiplicative C_ℓ ∝ ℓ^{-3} structure atop an exponential profile and consistent with ICM turbulence.
A Tapered Gridded Estimator (TGE) for the Multi-Frequency Angular Power Spectrum (MAPS) and the Cosmological HI 21-cm Power Spectrum
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
In this work we present a new approach to estimate the power spectrum $P({\bf k})$ of redshifted HI 21-cm brightness temperature fluctuations. The MAPS $C_{\ell}(\nu_a,\nu_b)$ completely quantifies the second order statistics of the sky signal under the assumption that the signal is statistically homogeneous and isotropic on the sky. Here we generalize an already existing visibility based estimator for $C_{\ell}$, namely TGE, to develop an estimator for $C_{\ell}(\nu_a,\nu_b)$. The 21-cm power spectrum is the Fourier transform of $C_{\ell}(\Delta \nu)$ with respect to $\Delta \nu=\mid \nu_a-\nu_b \mid$, and we use this to estimate $P({\bf k})$. Using simulations of $150 \, {\rm MHz}$ GMRT observations, we find that this estimator is able to recover $P(k)$ with an accuracy of $5-20 \%$ over a reasonably large $k$ range even when the data in $80 \%$ randomly chosen frequency channels is flagged.
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2026 3roles
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A review chapter summarizing advances in map-making and component-separation techniques for 21-cm intensity mapping to address systematics and foreground contamination in simulations for SKA-Mid.
Summarizes observational lessons on simulation pipelines and systematic mitigation from SKAO precursors for Cosmic Dawn and EoR studies.
citing papers explorer
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Intensity fluctuations of radio halo in galaxy cluster: Insights from power spectrum estimation
Angular power spectra of 610 MHz radio halos show excess power-law fluctuations only in Abell 2744, requiring multiplicative C_ℓ ∝ ℓ^{-3} structure atop an exponential profile and consistent with ICM turbulence.
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Methodological Frontiers in 21-cm Intensity Mapping: the Treatment of Systematics and Foreground Contamination
A review chapter summarizing advances in map-making and component-separation techniques for 21-cm intensity mapping to address systematics and foreground contamination in simulations for SKA-Mid.
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Observations of the Cosmic Dawn and Epoch of Reionization with the SKAO: Observational Lessons Learned from Precursors and Pathfinder Instruments
Summarizes observational lessons on simulation pipelines and systematic mitigation from SKAO precursors for Cosmic Dawn and EoR studies.