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The accurate and precise removal of 21-cm foregrounds from Epoch of Reionization redshifted 21-cm emission data is essential if we are to gain insight into an unexplored cosmological era. We apply a non-parametric technique, Generalized…

Current-generation low frequency interferometers constructed with the objective of detecting the high-redshift 21 cm background, aim to generate power spectra of the brightness-temperature contrast of neutral hydrogen in primordial…

Instrumentation and Methods for Astrophysics · Physics 2016-06-01 S. A. Kohn , J. Aguirre , C. Nunhokee , G. Bernardi , J. Pober , Z. Ali , R. Bradley , C. Carilli , D. DeBoer , N. Gugliucci , D. Jacobs , P. Klima , D. MacMahon , J. Manley , D. Moore , A. Parsons , I. Stefan , W. Walbrugh

We introduce a new method for performing robust Bayesian estimation of the three-dimensional spatial power spectrum at the Epoch of Reionization (EoR), from interferometric observations. The versatility of this technique allows us to…

Instrumentation and Methods for Astrophysics · Physics 2018-11-06 Peter H. Sims , Lindley Lentati , Jonathan C. Pober , Chris Carilli , Michael P. Hobson , Paul Alexander , Paul Sutter

One of the aims of the Low Frequency Array (LOFAR) Epoch of Reionization (EoR) project is to measure the power spectrum of variations in the intensity of redshifted 21-cm radiation from the EoR. The sensitivity with which this power…

The cosmic 21-cm signal promises to revolutionize studies of the Epoch of Reionization (EoR). Radio interferometers are aiming for a preliminary, low signal-to-noise (S/N) detection of the 21-cm power spectrum. Cross-correlating 21-cm with…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-09 Samuel Gagnon-Hartman , James E. Davies , Andrei Mesinger

We have completed a robotic wide-angle imaging survey of the southern sky (declination less than +15 degrees) at 656.3 nm wavelength, the H-alpha emission line of hydrogen. Each image of the resulting Southern H-Alpha Sky Survey Atlas…

Astrophysics · Physics 2008-11-26 J. E. Gaustad , P. R. McCullough , W. Rosing , D. Van Buren

Direct detection of the Dark Ages and the Epoch of Reionization (EOR) is among the main scientific objectives of all current and future low-frequency radio facilities. In this paper we summarize and discuss recent results, based on…

Astrophysics · Physics 2008-11-26 Ilian T. Iliev , Garrelt Mellema , Ue-Li Pen , Paul R. Shapiro

Interferometric experiments of the reionization era offer the advantages of measuring power in spatial modes with increased sensitivity afforded by multiple independent sky measurements. Here we review early work to measure this signal,…

Instrumentation and Methods for Astrophysics · Physics 2019-09-30 Cathryn M. Trott , Jonathan C. Pober

SKA-MID surveys will be the first in the radio domain to achieve clearly sub-arcsecond resolution at high sensitivity over large areas, opening new science applications for galaxy evolution. To investigate the potential of these surveys, we…

Accurate modelling of the primary beam is an important but difficult task in radio astronomy. For high dynamic range problems such as 21cm intensity mapping, small modelling errors in the sidelobes and spectral structure of the beams can…

Instrumentation and Methods for Astrophysics · Physics 2024-07-25 Michael J. Wilensky , Jacob Burba , Philip Bull , Hugh Garsden , Katrine A. Glasscock , Nicolas Fagnoni , Eloy de Lera Acedo , David R. DeBoer , Nima Razavi-Ghods

EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope, due to be completed in 2012. The primary goal of EMU is to make a deep ($\sim 10\mu$Jy/bm rms) radio continuum…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Ray P. Norris

One of the key science goals for the most sensitive telescopes, both current and upcoming, is the detection of the redshifted 21-cm signal from the Cosmic Dawn and Epoch of Reionization. The success of detection relies on accurate…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-13 Aishrila Mazumder , Arnab Chakraborty , Abhirup Datta , Samir Choudhuri , Nirupam Roy , Yogesh Wadadekar , C. H. Ishwara-Chandra

Aiming to correctly restore the redshifted 21 cm signals emitted by the neutral hydrogen during the cosmic reionization processes, we re-examine the separation approaches based on the quadratic polynomial fitting technique in frequency…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jingying Wang , Haiguang Xu , Tao An , Junhua Gu , Xueying Guo , Weitian Li , Yu Wang , Chengze Liu , Olivier Martineau-Huynh , Xiang-Ping Wu

The SZE-21cm has been proposed as an alternative probe for the Dark Ages (DA) and the Epoch of Reionization (EoR). The effect is produced when photons of the 21cm background are inverse Compton (up-)scattered by electrons residing in hot…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-03 Charles Mpho Takalana , Paolo Marchegiani , Sergio Colafrancesco

The Galactic magnetic field (GMF) plays a role in many astrophysical processes and is a significant foreground to cosmological signals, such as the Epoch of Reionization (EoR), but is not yet well understood. Dispersion and Faraday rotation…

Instrumentation and Methods for Astrophysics · Physics 2018-08-22 C. Sobey , the LOFAR , MWA collaborations

Unaccounted for systematics from foregrounds and instruments can severely limit the sensitivity of current experiments from detecting redshifted 21~cm signals from the Epoch of Reionization (EoR). Upcoming experiments are faced with a…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-06 Nithyanandan Thyagarajan , Aaron Parsons , David DeBoer , Judd Bowman , Aaron Ewall-Wice , Abraham Neben , Nipanjana Patra

One of the critical challenges facing imaging studies of the 21-cm signal at the Epoch of Reionization (EoR) is the separation of astrophysical foreground contamination. These foregrounds are known to lie in a wedge-shaped region of…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-27 Samuel Gagnon-Hartman , Yue Cui , Jacob Kennedy , Adrian Liu , Siamak Ravanbakhsh

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

Experiments designed to measure the redshifted 21~cm line from the Epoch of Reionization (EoR) are challenged by strong astrophysical foreground contamination, ionospheric distortions, complex instrumental response and other different types…

Radio interferometers can potentially detect the sky-averaged signal from the Cosmic Dawn (CD) and the Epoch of Reionisation (EoR) by studying the Moon as a thermal block to the foreground sky. The first step is to mitigate the Earth-based…

Instrumentation and Methods for Astrophysics · Physics 2023-12-19 Himanshu Tiwari , Benjamin McKinley , Cathryn M. Trott , Nithyanandan Thyagarajan
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