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This paper summarizes some of the major calibration and image reconstruction techniques used in radio interferometry and describes them in a common mathematical framework. The use of this framework has a number of benefits, ranging from…

Instrumentation and Methods for Astrophysics · Physics 2009-11-26 U. Rau , S. Bhatnagar , M. A. Voronkov , T. J. Cornwell

This paper explores the potential for statistical epoch of reionization (EOR) measurements using wide field radio observations. New developments in low frequency radio instrumentation and signal processing allow very sensitive EOR…

Astrophysics · Physics 2009-11-10 Miguel F. Morales , Jacqueline Hewitt

We present a catalog of 624 radio sources detected around the North Celestial Pole (NCP) with the 21 Centimeter Array (21CMA), a radio interferometer dedicated to the statistical measurement of the epoch of reionization (EoR). The data are…

Astrophysics of Galaxies · Physics 2016-12-14 Qian Zheng , Xiang-Ping Wu , Melanie Johnston-Hollitt , Jun-Hua Gu , Haiguang Xu

The interferometric technique known as peeling addresses many of the challenges faced when observing with low-frequency radio arrays, and is a promising tool for the associated calibration systems. We investigate a real-time peeling…

Radio interferometry is an observational technique used to study astrophysical phenomena. Data gathered by an interferometer requires substantial processing before astronomers can extract the scientific information from it. Data processing…

Instrumentation and Methods for Astrophysics · Physics 2024-12-24 Brian M. Kirk , Urvashi Rau , Ramyaa Ramyaa

The primary scientific results of the future space-based gravitational wave interferometer LISA will come from the parameter inference of a large variety of gravitational wave sources. However, the presence of calibration errors could…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Etienne Savalle , Jonathan Gair , Lorenzo Speri , Stanislav Babak

Using Fisher information and the Cram\'er-Rao lower bound, we analyse fundamental precision limits in the determination of spectral parameters in inelastic optical scattering. General analytic formulae are derived which account for the…

Instrumentation and Detectors · Physics 2019-04-03 Peter Török , Matthew R. Foreman

We present a sophisticated statistical point-source foreground model for low-frequency radio Epoch of Reionization (EoR) experiments using the 21 cm neutral hydrogen emission line. Motivated by our understanding of the low-frequency radio…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-16 Steven G. Murray , Cathryn M. Trott , Christopher H. Jordan

Radio interferometers are phased arrays producing high-resolution images from the covariance matrix of measurements. Calibration of such instruments is necessary and is a critical task. This is how the estimation of instrumental errors is…

Instrumentation and Methods for Astrophysics · Physics 2023-09-26 Yassine Mhiri , Mohammed Nabil El Korso , Arnaud Breloy , Pascal Larzabal

Using the latest upper limits on the 21-cm power spectrum at $z\approx9.1$ from the Low Frequency Array (LOFAR), we explore regions of parameter space which are inconsistent with the data. We use 21CMMC, a Monte Carlo Markov Chain sampler…

We perform a Fisher analysis to estimate the expected constraints on the Epoch of Reionization (EoR) model parameters (i.e., minimum virial temperature, the ionizing efficiency and the mean free path of ionizing photons) taking into account…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-04 Hayato Shimabukuro , Shintaro Yoshiura , Keitaro Takahashi , Shuichiro Yokoyama , Kiyotomo Ichiki

(Abridged) Noise considerations for experiments that aim to statistically estimate the 21 cm signal from high redshift neutral hydrogen during the Epoch of Reionisation (EoR) using interferometric data are typically computed assuming a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Cathryn M. Trott

We present new upper limits on the 21-cm signal power spectrum from the Epoch of Reionization (EoR), at redshifts $z \approx 10.1, 9.1, \text{ and } 8.3$, based on reprocessed observations from the Low-Frequency Array (LOFAR). The analysis…

We present techniques developed to calibrate and correct Murchison Widefield Array (MWA) low frequency (72-300 MHz) radio observations for polarimetry. The extremely wide field-of-view, excellent instantaneous (u, v)-coverage and…

The Epoch of Reionization (EoR) features a rich interplay between the first luminous sources and the low-density gas of the intergalactic medium (IGM), where photons from these sources ionize the IGM. There are currently few observational…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-07 Paul La Plante , Michelle Ntampaka

We analyse the accuracy of radio interferometric gridding of visibilities with the aim to quantify the Epoch of Reionization (EoR) 21-cm power spectrum bias caused by gridding, ultimately to determine the suitability of different imaging…

Instrumentation and Methods for Astrophysics · Physics 2019-10-16 A. R. Offringa , F. Mertens , S. van der Tol , B. Veenboer , B. K. Gehlot , L. V. E. Koopmans , M. Mevius

We quantify the effect of radio frequency interference (RFI) on measurements of the 21-cm power spectrum during the Epoch of Reionization (EoR). Specifically, we investigate how the frequency structure of RFI source emission generates…

Instrumentation and Methods for Astrophysics · Physics 2020-09-09 Michael J. Wilensky , Nichole Barry , Miguel F. Morales , Bryna J. Hazelton , Ruby Byrne

We explore the ability of measurements of the 21-cm power spectrum during reionization to enable the simultaneous reconstruction of the reionization history and the properties of the ionizing sources. For various sets of simulated 21-cm…

Astrophysics · Physics 2015-05-13 Rennan Barkana

The power spectra of the redshifted 21-cm signal from the Epoch of Reionization (EoR) contain information about the ionization and thermal states of the intergalactic medium (IGM), and depend on the properties of the EoR sources. Recently,…

Radio frequency interference (RFI) is the principal factor limiting the sensitivities of radio telescopes, particularly at frequencies below 1 GHz. I present a conceptually new approach to mitigation of RFI in interferometric data. This has…

Instrumentation and Methods for Astrophysics · Physics 2011-02-11 Ramana Athreya