159 citations · 1.1k across the 18 of their papers we have counts for
18 papers
Probing Ionospheric Structures using the LOFAR radio telescope
M. Mevius, S. van der Tol, V. N. Pandey +24
LOFAR is the LOw Frequency Radio interferometer ARray located at mid-latitude (). Here, we present results on ionospheric structures derived from 29 LOFAR nighttim…
Linear polarization structures in LOFAR observations of the interstellar medium in the 3C196 field
V. Jelić, A. G. de Bruyn, V. N. Pandey +21
This study aims to characterize linear polarization structures in LOFAR observations of the interstellar medium (ISM) in the 3C196 field, one of the primary fields of the LOFAR-Epo…
Simulating the 21cm forest detectable with LOFAR and SKA in the spectra of high-z GRBs
B. Ciardi, S. Inoue, F. B. Abdalla +26
We investigate the feasibility of detecting 21cm absorption features in the afterglow spectra of high redshift long Gamma Ray Bursts (GRBs). This is done employing simulations of c…
Collaborative Randomized Beamforming for Phased Array Radio Interferometers
Orhan Ocal, Paul Hurley, Giovanni Cherubini +1
The Square Kilometre Array (SKA) will form the largest radio telescope ever built and such a huge instrument in the desert poses enormous engineering and logistic challenges. Algor…
Lunar occultation of the diffuse radio sky: LOFAR measurements between 35 and 80 MHz
H. K. Vedantham, L. V. E. Koopmans, A. G. de Bruyn +91
We present radio observations of the Moon between and MHz to demonstrate a novel technique of interferometrically measuring large-scale diffuse emission extending far bey…
Initial LOFAR observations of Epoch of Reionization windows: II. Diffuse polarized emission in the ELAIS-N1 field
V. Jelic, A. G. de Bruyn, M. Mevius +106
This study aims to characterise the polarized foreground emission in the ELAIS-N1 field and to address its possible implications for the extraction of the cosmological 21-cm signal…
Constraining the epoch of reionization with the variance statistic: simulations of the LOFAR case
Ajinkya H. Patil, Saleem Zaroubi, Emma Chapman +27
Several experiments are underway to detect the cosmic redshifted 21-cm signal from neutral hydrogen from the Epoch of Reionization (EoR). Due to their very low signal-to-noise rati…
Robust Radio Interferometric Calibration Using the t-Distribution
S. Kazemi, S. Yatawatta
A major stage of radio interferometric data processing is calibration or the estimation of systematic errors in the data and the correction for such errors. A stochastic error (noi…
Radio Interferometric Calibration via Ordered-Subsets Algorithms: OS-LS and OS-SAGE calibrations
S. Kazemi, S. Yatawatta, S. Zaroubi
The main objective of this work is to accelerate the Maximum-Likelihood (ML) estimation procedure in radio interferometric calibration. We introduce the OS-LS and the OS-SAGE radio…
Probing reionization with LOFAR using 21-cm redshift space distortions
Hannes Jensen, Kanan K. Datta, Garrelt Mellema +24
One of the most promising ways to study the epoch of reionization (EoR) is through radio observations of the redshifted 21-cm line emission from neutral hydrogen. These observation…
Initial deep LOFAR observations of Epoch of Reionization windows: I. The North Celestial Pole
S. Yatawatta, A. G. de Bruyn, M. A. Brentjens +86
The aim of the LOFAR Epoch of Reionization (EoR) project is to detect the spectral fluctuations of the redshifted HI 21cm signal. This signal is weaker by several orders of magnitu…
Clustered Calibration: An Improvement to Radio Interferometric Direction Dependent Self-Calibration
Sanaz Kazemi, Sarod Yatawatta, Saleem Zaroubi
The new generation of radio synthesis arrays, such as LOFAR and SKA, have been designed to surpass existing arrays in terms of sensitivity, angular resolution and frequency coverag…
Prospects for detecting the 21cm forest from the diffuse intergalactic medium with LOFAR
B. Ciardi, P. Labropoulos, A. Maselli +20
We discuss the feasibility of the detection of the 21cm forest in the diffuse IGM with the radio telescope LOFAR. The optical depth to the 21cm line has been derived using simulati…
The LOFAR radio environment
A. R. Offringa, A. G. de Bruyn, S. Zaroubi +93
Aims: This paper discusses the spectral occupancy for performing radio astronomy with the Low-Frequency Array (LOFAR), with a focus on imaging observations. Methods: We have analys…
LOFAR insights into the epoch of reionization from the cross power spectrum of 21cm emission and galaxies
R. P. C. Wiersma, B. Ciardi, R. M. Thomas +18
Using a combination of N-body simulations, semi-analytic models and radiative transfer calculations, we have estimated the theoretical cross power spectrum between galaxies and the…
Imaging neutral hydrogen on large-scales during the Epoch of Reionization with LOFAR
S. Zaroubi, A. G. de Bruyn, G. Harker +17
The first generation of redshifted 21 cm detection experiments, carried out with arrays like LOFAR, MWA and GMRT, will have a very low signal-to-noise ratio per resolution element…
Clustered Radio Interferometric Calibration
Sanaz Kazemi, Sarod Yatawatta, Saleem Zaroubi
This paper introduces an amendment to radio interferometric calibration of sources below the noise level. The main idea is to employ the information of the stronger sources' measur…
Radio Interferometric Calibration Using The SAGE Algorithm
S. Kazemi, S. Yatawatta, S. Zaroubi +3
The aim of the new generation of radio synthesis arrays such as LOFAR and SKA is to achieve much higher sensitivity, resolution and frequency coverage than what is available now, e…