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We report improved measurements of temperature anisotropies in the cosmic microwave background (CMB) radiation made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). In this paper, we use a new analysis technique and include…

We present a comprehensive simulation-based study of the BayesEoR code for 21 cm power spectrum recovery when analytically marginalizing over foreground parameters. To account for covariance between the 21 cm signal and contaminating…

Instrumentation and Methods for Astrophysics · Physics 2023-02-09 Jacob Burba , Peter H. Sims , Jonathan C. Pober

The remarkable improvement in the estimates of different cosmological parameters in recent years has been largely spearheaded by accurate measurements of the angular power spectrum of Cosmic Microwave Background (CMB) radiation. This has…

Astrophysics · Physics 2011-04-11 Tarun Souradeep , Rajib Saha , Pankaj Jain

We describe a fast and accurate method for estimation of the cosmic microwave background (CMB) anisotropy angular power spectrum --- Monte Carlo Apodised Spherical Transform EstimatoR. Originally devised for use in the interpretation of the…

Astrophysics · Physics 2011-08-11 E. Hivon , K. M. Gorski , C. B. Netterfield , B. P. Crill , S. Prunet , F. Hansen

In recent years, a Gaussian Process Regression (GPR) based framework has been developed for foreground mitigation from data collected by the LOw-Frequency ARray (LOFAR), to measure the 21-cm signal power spectrum from the Epoch of…

We study the position-dependent power spectrum and the integrated bispectrum statistic for 2D cosmological fields on the sphere (integrated angular bispectrum). First, we derive a useful, $m$-independent, formula for the full-sky integrated…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-19 Gabriel Jung , Filippo Oppizzi , Andrea Ravenni , Michele Liguori

The most promising near-term observable of the cosmic dark age prior to widespread reionization (z~15-200) is the sky-averaged \lambda 21 cm background arising from hydrogen in the intergalactic medium. Though an individual antenna could in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 G. Bernardi , M. McQuinn , L. J. Greenhill

We compute the expected angular power spectrum of the cosmic Far Infrared Background (FIRB). We find that the signal due to source correlations dominates the shot--noise for $\ell \la 1000$ and results in anisotropies with rms amplitudes…

Astrophysics · Physics 2008-11-26 Zoltan Haiman , Lloyd Knox

Optical tweezers and AFM cantilevers are often calibrated by fitting their experimental powerspectra of Brownian motion. We demonstrate here that if this is done with typical weighted least-squares methods the result is a bias of relative…

Instrumentation and Detectors · Physics 2014-11-20 Simon F. Norrelykke , Henrik Flyvbjerg

Observations of the EoR with the 21-cm hyperfine emission of neutral hydrogen (HI) promise to open an entirely new window onto the formation of the first stars, galaxies and accreting black holes. In order to characterize the weak 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-06 Abhik Ghosh , L. V. E. Koopmans , Emma Chapman , Vibor Jelic

The power spectrum of redshifted 21 cm emission brightness temperature fluctuations is a powerful probe of the Epoch of Reionization (EoR). However, bright foreground emission presents a significant impediment to its unbiased recovery from…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-31 Peter H. Sims , Jonathan C. Pober

We have analysed the Rhodes/HartRAO survey at 2326 MHz and derived the global angular power spectrum of Galactic continuum emission. In order to measure the angular power spectrum of the diffuse component, point sources were removed from…

Astrophysics · Physics 2009-11-06 G. Giardino , A. J. Banday , P. Fosalba , K. M. Gorski , J. L. Jonas , W. O'Mullane , J. Tauber

The 21-cm signal from neutral hydrogen is anticipated to reveal critical insights into the formation of early cosmic structures during the Cosmic Dawn and the subsequent Epoch of Reionization. However, the intrinsic faintness of the signal,…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Yuchen Liu , Eloy de Lera Acedo , Peter Sims

Direct detection of the Epoch of Reionization (EoR) via the red-shifted 21-cm line will have unprecedented implications on the study of structure formation in the infant Universe. To fulfill this promise, current and future 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Abhik Ghosh , Florent Mertens , Leon V. E. Koopmans

Observation of the redshifted 21-cm signal from Cosmic Dawn and Epoch of Reionization is a challenging endeavor in observational cosmology. Presence of orders of magnitude brighter astrophysical foregrounds and various instrumental…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-03 Aishrila Mazumder , Abhirup Datta , Arnab Chakraborty , Suman Majumdar

The expansion and upgrade of the global network of ground-based gravitational wave detectors promises to improve our capacity to infer the sky-localization of transient sources, enabling more effective multi-messenger follow-ups. At the…

General Relativity and Quantum Cosmology · Physics 2024-04-29 Mattia Emma , Tiago Fernandes de Nobrega , Gregory Ashton

The radio sky at lower frequencies, particularly below 20 MHz, is expected to be a combination of increasingly bright non-thermal emission and significant absorption from intervening thermal plasma. The sky maps at these frequencies cannot…

Instrumentation and Methods for Astrophysics · Physics 2021-09-01 Akhil Jaini , Avinash A. Deshpande , Sainath Bitragunta

Foreground removal is a major challenge for detecting the redshifted 21-cm neutral hydrogen (HI) signal from the Epoch of Reionization (EoR). We have used 150 MHz GMRT observations to characterize the statistical properties of the…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-24 Abhik Ghosh , Jayanti Prasad , Somnath Bharadwaj , Sk. Saiyad Ali , Jayaram N. Chengalur

The precise measurement of the sky-averaged HI absorption signal between 50 and 200 MHz is the primary goal of global 21-cm cosmology. This measurement has the potential to unravel the underlying physics of cosmic structure formation and…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-04 Emma Shen , Dominic Anstey , Marta Spinelli , Eloy de Lera Acedo , Anastasia Fialkov

Sky-coverage in laser-assisted AO observations largely depends on the system's capability to guide on the faintest natural guide-stars possible. Here we give an up-to-date status of our natural guide-star processing tailored to the…

Instrumentation and Methods for Astrophysics · Physics 2016-11-23 Carlos M. Correia , Benoit Neichel , Jean-Marc Conan , Cyril Petit , Jean-Francois Sauvage , Thierry Fusco , Joel D. R. Vernet , Niranjan Thatte