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We present the angular power spectrum derived from the first-year Wilkinson Microwave Anisotropy Probe (WMAP) sky maps. We study a variety of power spectrum estimation methods and data combinations and demonstrate that the results are…

Spectra of astronomical targets acquired from ground-based instruments are affected by the atmospheric transmission. The authors and their institutes are developing a web-based service, TAPAS (Transmissions of the AtmosPhere for…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 J. L. Bertaux , R. Lallement , S. Ferron , C. Boone , R. Bodichon

We present a new method for probing the thermal electron content of the Galaxy by spectral analysis of background point sources in the absorption-only limit to the radiative transfer equation. In this limit, calculating the spectral index,…

High Energy Astrophysical Phenomena · Physics 2016-05-25 D. I. Jones , A. P. Igoshev , M. Haverkorn

We present a method for measuring CMB polarization power spectra given incomplete sky coverage and test it with simulated examples such as Boomerang 2001 and MAP. By augmenting the quadratic estimator method with an additional step, we find…

Astrophysics · Physics 2009-10-07 Max Tegmark , Angelica de Oliveira-Costa

Radio interferometric data are used to estimate the sky brightness distributions in radio frequencies. Here we focus on estimators of the large-scale structure and the power spectrum of the sky brightness distribution inferred from radio…

Instrumentation and Methods for Astrophysics · Physics 2019-04-17 Prasun Dutta , Meera Nandakumar

The post-reionization $(z \le 6)$ neutral hydrogen (HI) 21-cm intensity mapping signal holds the potential to probe the large scale structures, study the expansion history and constrain various cosmological parameters. Here we apply the…

Neutral hydrogen ($\rm{HI}$) $21$-cm intensity mapping (IM) offers an efficient technique for mapping the large-scale structures in the universe. We introduce the 'Cross' Tapered Gridded Estimator (Cross TGE), which cross-correlates two…

Drift scan observations provide the broad sky coverage and instrumental stability needed to measure the Epoch of Reionization (EoR) 21-cm signal. In such observations, the telescope's pointing center (PC) moves continuously on the sky. The…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-20 Suman Chatterjee , Khandakar Md Asif Elahi , Somnath Bharadwaj , Shouvik Sarkar , Samir Choudhuri , Shiv Sethi , Akash Kumar Patwa

Measurement of the angular power spectrum of the cosmic microwave background is most often based on a spherical harmonic analysis of the observed temperature anisotropies. Even if all-sky maps are obtained, however, it is likely that the…

Astrophysics · Physics 2009-10-31 Daniel J. Mortlock , Anthony D. Challinor , Michael P. Hobson

We present a Bayesian angular power spectrum and signal map inference engine which can be adapted to interferometric observations of anisotropies inthe cosmic microwave background, 21 cm emission line mapping of galactic brightness…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 P. M. Sutter , Benjamin D. Wandelt , Siddharth Malu

This study investigates some of the consequences of representing the sky by a rectangular grid of pixels on the dynamic range of images derived from radio interferometric measurements. In particular, the effects of image pixelization…

Astrophysics · Physics 2009-11-13 W. D. Cotton , Juan M. Uson

There is enormous potential to advance cosmology from statistical characterizations of cosmic microwave background sky maps. The angular power spectrum of the microwave anisotropy is a particularly important statistic. Existing algorithms…

Astrophysics · Physics 2009-10-30 Siang Peng Oh , David N. Spergel , Gary Hinshaw

21cm tomography promises to be a powerful tool for estimating cosmological parameters, constraining the epoch of reionization, and probing the so-called dark ages. However, realizing this promise will require the extraction of a…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Adrian Liu , Max Tegmark

Our position inside the Galaxy requires all-sky surveys to reveal its large-scale properties. The zero-level calibration of all-sky surveys differs from standard 'relative' measurements, where a source is measured in respect to its…

Astrophysics · Physics 2009-11-13 Wolfgang Reich , Patricia Reich

We present an alternative estimate of the unresolved point source contribution to the WMAP temperature power spectrum based on current knowledge of sources from radio surveys in the 1.4-90 GHz range. We implement a stochastic extrapolation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Loris P. L. Colombo , Elena Pierpaoli

The redshifted 21cm signal of neutral hydrogen from the epoch of reionization (EoR) is extremely weak and its first detection is therefore expected to be statistical with first-generation low-frequency radio interferometers. In this letter…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Qian Zheng , Xiang-ping Wu , Jun-hua Gu , Jingying Wang , Haiguang Xu

5th Generation Mobile Network Systems(5G systems) operating in milli-meter Wave (mmW) bands will employ base stations with integrated Active Antenna Systems (AASs) capable of beam-tracking using narrow beams obtained from array antennas…

Signal Processing · Electrical Eng. & Systems 2018-04-04 Jonas Fridén , Aidin Razavi , Anders Stjernman

Much attention has been given to the problem of estimating cosmological parameters from the $C_l$ measured by future experiments. Many of the approaches which are being used either invoke poorly controlled approximations or are…

Astrophysics · Physics 2007-05-23 Benjamin D. Wandelt , Eric Hivon , Krzysztof M. Gorski

Ground-based astronomical observations at thermal infrared wavelengths face the problem of extracting the weak astronomical signal from the large and rapidly variable background flux. The observing strategy most commonly used, the so-called…

Astrophysics · Physics 2009-10-31 M. Bertero , P. Boccacci , M. Robberto

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