654 citations · 11.3k across the 278 of their papers we have counts for
21 papers · 1 filter
Polarisation and Faraday rotation measure imaging at metre wavelengths with sub-arcsecond resolution: a foundational calibration strategy
R. J. van Weeren, J. M. G. H. J. de Jong, X. K Le Saux +12
Low-frequency radio polarimetric observations provide a powerful probe of magnetic fields in astrophysical sources and the intervening medium, as well as magnetospheric emission fr…
A decade of sub-arcsecond imaging with the International LOFAR Telescope
Leah K. Morabito, Neal Jackson, Jurjen de Jong +7
The International LOFAR Telescope (ILT) is a pan-European radio interferometer with baselines up to 2,000 km. This provides sub-arcsecond resolution at frequencies of <200 MHz. Sin…
Unlocking ultra-deep wide-field imaging with sidereal visibility averaging
J. M. G. H. J. de Jong, R. J. van Weeren, T. J. Dijkema +3
Producing ultra-deep high-angular-resolution images with current and next-generation radio interferometers introduces significant computational challenges. In particular, the imagi…
Into the depths: Unveiling ELAIS-N1 with LOFAR's deepest sub-arcsecond wide-field images
J. M. G. H. J. de Jong, R. J. van Weeren, F. Sweijen +11
We present the deepest wide-field 115-166 MHz image at sub-arcsecond resolution spanning an area of 2.5 by 2.5 degrees centred at the ELAIS-N1 deep field. To achieve this, we impro…
Characterization of the decametre sky at subarcminute resolution
C. Groeneveld, R. J. van Weeren, E. Osinga +11
The largely unexplored decameter radio band (10-30 MHz) provides a unique window for studying a range of astronomical topics, such as auroral emission from exoplanets, inefficient…
1-arcsecond imaging of ELAIS-N1 field at 144MHz using the LoTSS survey with international LOFAR telescope
Haoyang Ye, Frits Sweijen, Reinout van Weeren +10
We present the first wide area (2.5 x 2.5 deg^2) LOFAR High Band Antenna image at a resolution of 1.2'' x 2'' with a median noise of approximately 80 microJy per beam. It was made…
A novel radio imaging method for physical spectral index modelling
E. Ceccotti, A. R. Offringa, L. V. E. Koopmans +9
We present a new method, called "forced-spectrum fitting", for physically-based spectral modelling of radio sources during deconvolution. This improves upon current common deconvol…
Sub-arcsecond imaging with the International LOFAR Telescope I. Foundational calibration strategy and pipeline
L. K. Morabito, N. J. Jackson, S. Mooney +71
[abridged] The International LOFAR Telescope is an interferometer with stations spread across Europe. With baselines of up to ~2,000 km, LOFAR has the unique capability of achievin…
The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary Data Release
T. W. Shimwell, H. J. A. Röttgering, P. N. Best +69
The LOFAR Two-metre Sky Survey (LoTSS) is a deep 120-168 MHz imaging survey that will eventually cover the entire Northern sky. Each of the 3170 pointings will be observed for 8 hr…
LBCS: the LOFAR Long-Baseline Calibrator Survey
N. Jackson, A. Tagore, A. Deller +76
(abridged). We outline LBCS (the LOFAR Long-Baseline Calibrator Survey), whose aim is to identify sources suitable for calibrating the highest-resolution observations made with the…
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…
LOFAR facet calibration
R. J. van Weeren, W. L. Williams, M. J. Hardcastle +39
LOFAR, the Low-Frequency Array, is a powerful new radio telescope operating between 10 and 240 MHz. LOFAR allows detailed sensitive high-resolution studies of the low-frequency rad…
The LOFAR Multifrequency Snapshot Sky Survey (MSSS) I. Survey description and first results
G. H. Heald, R. F. Pizzo, E. Orrú +147
We present the Multifrequency Snapshot Sky Survey (MSSS), the first northern-sky LOFAR imaging survey. In this introductory paper, we first describe in detail the motivation and de…
Calibrating the absolute amplitude scale for air showers measured at LOFAR
A. Nelles, J. R. Hörandel, T. Karskens +74
Air showers induced by cosmic rays create nanosecond pulses detectable at radio frequencies. These pulses have been measured successfully in the past few years at the LOw Frequency…
Measuring a Cherenkov ring in the radio emission from air showers at 110-190 MHz with LOFAR
A. Nelles, P. Schellart, S. Buitink +66
Measuring radio emission from air showers offers a novel way to determine properties of the primary cosmic rays such as their mass and energy. Theory predicts that relativistic tim…
The LOFAR long baseline snapshot calibrator survey
J. Moldón, A. T. Deller, O. Wucknitz +82
Aims. An efficient means of locating calibrator sources for International LOFAR is developed and used to determine the average density of usable calibrator sources on the sky for s…
Comparison of algorithms for determination of rotation measure and Faraday structure I. 1100 - 1400 MHz
X. H. Sun, L. Rudnick, Takuya Akahori +14
(abridged) We run a Faraday structure determination data challenge to benchmark the currently available algorithms including Faraday synthesis (previously called RM synthesis in th…
Detecting cosmic rays with the LOFAR radio telescope
P. Schellart, A. Nelles, S. Buitink +102
The low frequency array (LOFAR), is the first radio telescope designed with the capability to measure radio emission from cosmic-ray induced air showers in parallel with interferom…
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…
LOFAR: opening a new window on low frequency radio astronomy
R. Morganti, G. Heald, J. Hessels +8
This contribution reports on the status of LOFAR (the LOw Frequency ARray) in its ongoing commissioning phase. The purpose is to illustrate the progress that is being made, often o…
Progress with the LOFAR Imaging Pipeline
George Heald, John McKean, Roberto Pizzo +14
One of the science drivers of the new Low Frequency Array (LOFAR) is large-area surveys of the low-frequency radio sky. Realizing this goal requires automated processing of the int…