LOFAR: The low-frequency array
Review article, 2013
LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer constructed in the north of the Netherlands and across europe. Utilizing a novel phased-array design, LOFAR covers the largely unexplored low-frequency range from 10-240 MHz and provides a number of unique observing capabilities. Spreading out from a core located near the village of Exloo in the northeast of the Netherlands, a total of 40 LOFAR stations are nearing completion. A further five stations have been deployed throughout Germany, and one station has been built in each of France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR achieves unparalleled sensitivity and angular resolution in the low-frequency radio regime. The LOFAR facilities are jointly operated by the International LOFAR Telescope (ILT) foundation, as an observatory open to the global astronomical community. LOFAR is one of the first radio observatories to feature automated processing pipelines to deliver fully calibrated science products to its user community. LOFAR's new capabilities, techniques and modus operandi make it an important pathfinder for the Square Kilometre Array (SKA). We give an overview of the LOFAR instrument, its major hardware and software components, and the core science objectives that have driven its design. In addition, we present a selection of new results from the commissioning phase of this new radio observatory. © ESO 2013.
Dark ages, reionization, first stars
Radio lines: General
Radio continuum: General
Telescopes
Instrumentation: Interferometers
Author
M. P. van Haarlem
Netherlands Institute for Radio Astronomy (ASTRON)
M. W. Wise
Netherlands Institute for Radio Astronomy (ASTRON)
A.W. Gunst
Netherlands Institute for Radio Astronomy (ASTRON)
G. Heald
Netherlands Institute for Radio Astronomy (ASTRON)
J. McKean
Netherlands Institute for Radio Astronomy (ASTRON)
J. W. T. Hessels
Netherlands Institute for Radio Astronomy (ASTRON)
A. G. de Bruyn
Netherlands Institute for Radio Astronomy (ASTRON)
R. Nijboer
Netherlands Institute for Radio Astronomy (ASTRON)
J. Swinbank
Anton Pannekoek Institute for Astronomy
R. A. Fallows
Netherlands Institute for Radio Astronomy (ASTRON)
M. Brentjens
Netherlands Institute for Radio Astronomy (ASTRON)
A. Nelles
Radboud University
R. Beck
Max Planck Society
H.D. Falcke
Netherlands Institute for Radio Astronomy (ASTRON)
R. P. Fender
University of Southampton
J.R. Hörandel
Radboud University
L.V.E. Koopmans
University of Groningen
G. Mann
Leibniz Institute for Astrophysics Potsdam
G. Miley
Leiden University
H. Rottgering
Leiden University
B.W. Stappers
University of Manchester
Ramj Wijers
Anton Pannekoek Institute for Astronomy
S. Zaroubi
University of Groningen
M. Van Den Akker
Radboud University
A. Alexov
Anton Pannekoek Institute for Astronomy
J. M. Anderson
Max Planck Society
K. Anderson
Anton Pannekoek Institute for Astronomy
Arnold van Ardenne
Netherlands Institute for Radio Astronomy (ASTRON)
Chalmers, Earth and Space Sciences, Onsala Space Observatory
M. J. Arts
Netherlands Institute for Radio Astronomy (ASTRON)
A. Asgekar
Netherlands Institute for Radio Astronomy (ASTRON)
I.M. Avruch
Netherlands Institute for Radio Astronomy (ASTRON)
Fabien Batejat
Astronomy and Plasmaphysics
L. Bähren
Anton Pannekoek Institute for Astronomy
M.E. Bell
University of Southampton
M. R. Bell
Max Planck Society
I. van Bemmel
Netherlands Institute for Radio Astronomy (ASTRON)
P. Bennema
Netherlands Institute for Radio Astronomy (ASTRON)
M. J. Bentum
Netherlands Institute for Radio Astronomy (ASTRON)
G. Bernardi
University of Groningen
P.N. Best
University of Edinburgh
L. Birzan
Leiden University
A. Bonafede
Jacobs University Bremen
A.J. Boonstra
Netherlands Institute for Radio Astronomy (ASTRON)
R. Braun
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
J. Bregman
Netherlands Institute for Radio Astronomy (ASTRON)
F. Breitling
Leibniz Institute for Astrophysics Potsdam
R.H. Van De Brink
Netherlands Institute for Radio Astronomy (ASTRON)
J.W. Broderick
University of Southampton
P.C. Broekema
Netherlands Institute for Radio Astronomy (ASTRON)
W. N. Brouw
Netherlands Institute for Radio Astronomy (ASTRON)
M. Brueggen
University of Hamburg
H. R. Butcher
Netherlands Institute for Radio Astronomy (ASTRON)
W. van Cappellen
Netherlands Institute for Radio Astronomy (ASTRON)
B. Ciardi
Max Planck Society
T. Coenen
Anton Pannekoek Institute for Astronomy
John Conway
Chalmers, Earth and Space Sciences, Onsala Space Observatory
A. H.W.M. Coolen
Netherlands Institute for Radio Astronomy (ASTRON)
A. Corstanje
Radboud University
Sieds Damstra
Netherlands Institute for Radio Astronomy (ASTRON)
O. Davies
STFC Rutherford Appleton Laboratory
A. Deller
Netherlands Institute for Radio Astronomy (ASTRON)
R. -J. Dettmar
Ruhr-Universität Bochum
G. van Diepen
Netherlands Institute for Radio Astronomy (ASTRON)
K. Dijkstra
University of Groningen
P. Donker
Netherlands Institute for Radio Astronomy (ASTRON)
A. Doorduin
Netherlands Institute for Radio Astronomy (ASTRON)
J. Dromer
Netherlands Institute for Radio Astronomy (ASTRON)
M. Drost
Netherlands Institute for Radio Astronomy (ASTRON)
A. Van Duin
Netherlands Institute for Radio Astronomy (ASTRON)
J. Eisloffel
Thüringer Landessternwarte Tautenburg
J. Van Enst
Netherlands Institute for Radio Astronomy (ASTRON)
C. Ferrari
Observatoire de la Cote d'Azur
W. Frieswijk
Netherlands Institute for Radio Astronomy (ASTRON)
H. Gankema
University of Groningen
M. A. Garrett
Netherlands Institute for Radio Astronomy (ASTRON)
F. De Gasperin
Max Planck Society
M. Gerbers
Netherlands Institute for Radio Astronomy (ASTRON)
E. de Geus
Netherlands Institute for Radio Astronomy (ASTRON)
J.M. Grießmeier
Netherlands Institute for Radio Astronomy (ASTRON)
T. Grit
Netherlands Institute for Radio Astronomy (ASTRON)
P. Gruppen
Netherlands Institute for Radio Astronomy (ASTRON)
J.P. Hamaker
Netherlands Institute for Radio Astronomy (ASTRON)
T. E. Hassall
University of Manchester
M. Hoeft
Thüringer Landessternwarte Tautenburg
H. Holties
Netherlands Institute for Radio Astronomy (ASTRON)
A. Horneffer
Radboud University
A. J. van der Horst
Anton Pannekoek Institute for Astronomy
A. Van Houwelingen
Netherlands Institute for Radio Astronomy (ASTRON)
A. Huijgen
Netherlands Institute for Radio Astronomy (ASTRON)
M. Iacobelli
Leiden University
H. T. Intema
Leiden University
N. Jackson
University of Manchester
V. Jelić
Netherlands Institute for Radio Astronomy (ASTRON)
A. De Jong
Netherlands Institute for Radio Astronomy (ASTRON)
E. Juette
Ruhr-Universität Bochum
D. Kant
Netherlands Institute for Radio Astronomy (ASTRON)
A. Karastergiou
University of Oxford
A. Koers
Netherlands Institute for Radio Astronomy (ASTRON)
H. Kollen
Netherlands Institute for Radio Astronomy (ASTRON)
V.I. Kondratiev
Netherlands Institute for Radio Astronomy (ASTRON)
E. Kooistra
Netherlands Institute for Radio Astronomy (ASTRON)
Y. Koopman
Netherlands Institute for Radio Astronomy (ASTRON)
A. Koster
Netherlands Institute for Radio Astronomy (ASTRON)
M. Kuniyoshi
Max Planck Society
M. Kramer
University of Manchester
G. Kuper
Netherlands Institute for Radio Astronomy (ASTRON)
P. Lambropoulos
Netherlands Institute for Radio Astronomy (ASTRON)
C. Law
Anton Pannekoek Institute for Astronomy
J. van Leeuwen
Netherlands Institute for Radio Astronomy (ASTRON)
J. Lemaitre
Netherlands Institute for Radio Astronomy (ASTRON)
M. Loose
Netherlands Institute for Radio Astronomy (ASTRON)
P. Maat
Netherlands Institute for Radio Astronomy (ASTRON)
G. Macario
Observatoire de la Cote d'Azur
S. Markoff
Anton Pannekoek Institute for Astronomy
J. Masters
Anton Pannekoek Institute for Astronomy
R. McFadden
Netherlands Institute for Radio Astronomy (ASTRON)
D. McKay-Bukowski
STFC Rutherford Appleton Laboratory
H. Meijering
Netherlands Institute for Radio Astronomy (ASTRON)
H. Meulman
Netherlands Institute for Radio Astronomy (ASTRON)
M. Mevius
University of Groningen
E. Middelberg
Ruhr-Universität Bochum
R. Millenaar
Netherlands Institute for Radio Astronomy (ASTRON)
J. C. A. Miller-Jones
Anton Pannekoek Institute for Astronomy
R.N. Mohan
Leiden University
J.D. Mol
Netherlands Institute for Radio Astronomy (ASTRON)
J. Morawietz
Netherlands Institute for Radio Astronomy (ASTRON)
R. Morganti
Netherlands Institute for Radio Astronomy (ASTRON)
D. D. Mulcahy
Max Planck Society
E. Mulder
Netherlands Institute for Radio Astronomy (ASTRON)
H. Munk
Netherlands Institute for Radio Astronomy (ASTRON)
L. Nieuwenhuis
Netherlands Institute for Radio Astronomy (ASTRON)
R. Van Nieuwpoort
Netherlands Institute for Radio Astronomy (ASTRON)
J. E. Noordam
Netherlands Institute for Radio Astronomy (ASTRON)
M. J. Norden
Netherlands Institute for Radio Astronomy (ASTRON)
A. Noutsos
Max Planck Society
A. R. Offringa
University of Groningen
Hans Olofsson
Astronomy and Plasmaphysics
A. Omar
Netherlands Institute for Radio Astronomy (ASTRON)
E. Orrú
Netherlands Institute for Radio Astronomy (ASTRON)
R. E. Overeem
Netherlands Institute for Radio Astronomy (ASTRON)
H. Paas
University of Groningen
M. Pandey-Pommier
Leiden University
V. N. Pandey
University of Groningen
R. Pizzo
Netherlands Institute for Radio Astronomy (ASTRON)
A.G. Polatidis
Netherlands Institute for Radio Astronomy (ASTRON)
D. Rafferty
Leiden University
S. Rawlings
University of Oxford
W. Reich
Max Planck Society
J. P. de Reijer
Netherlands Institute for Radio Astronomy (ASTRON)
J. Reitsma
Netherlands Institute for Radio Astronomy (ASTRON)
G.A. Renting
Netherlands Institute for Radio Astronomy (ASTRON)
P. Riemers
Netherlands Institute for Radio Astronomy (ASTRON)
E. Rol
Anton Pannekoek Institute for Astronomy
J. W. Romein
Netherlands Institute for Radio Astronomy (ASTRON)
J. Roosjen
Netherlands Institute for Radio Astronomy (ASTRON)
Mark Ruiter
Netherlands Institute for Radio Astronomy (ASTRON)
A. M. M. Scaife
University of Southampton
K. Van Der Schaaf
Netherlands Institute for Radio Astronomy (ASTRON)
B. Scheers
Anton Pannekoek Institute for Astronomy
Pim Schellart
Radboud University
A. P. Schoenmakers
Netherlands Institute for Radio Astronomy (ASTRON)
G. Schoonderbeek
Netherlands Institute for Radio Astronomy (ASTRON)
M. Serylak
University of Orléans
A. Shulevski
University of Groningen
J. Sluman
Netherlands Institute for Radio Astronomy (ASTRON)
O. Smirnov
Netherlands Institute for Radio Astronomy (ASTRON)
C. Sobey
Max Planck Society
H. Spreeuw
Anton Pannekoek Institute for Astronomy
M. Steinmetz
Leibniz Institute for Astrophysics Potsdam
C.G.M. Sterks
University of Groningen
H.-J. Stiepel
Netherlands Institute for Radio Astronomy (ASTRON)
K. J.C. Stuurwold
Netherlands Institute for Radio Astronomy (ASTRON)
M. Tagger
University of Orléans
Y. Tang
Netherlands Institute for Radio Astronomy (ASTRON)
C. Tasse
LESIA - Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique
I. Thomas
Netherlands Institute for Radio Astronomy (ASTRON)
S. Thoudam
Radboud University
M. C. Toribio
Netherlands Institute for Radio Astronomy (ASTRON)
B. van der Tol
Leiden University
O. Usov
Leiden University
M. Van Veelen
Netherlands Institute for Radio Astronomy (ASTRON)
A.-J. Van Der Veen
Netherlands Institute for Radio Astronomy (ASTRON)
S. ter Veen
Radboud University
J. P.W. Verbiest
Max Planck Society
R. Vermeulen
Netherlands Institute for Radio Astronomy (ASTRON)
N. Vermaas
Netherlands Institute for Radio Astronomy (ASTRON)
C. Vocks
Leibniz Institute for Astrophysics Potsdam
C. Vogt
Netherlands Institute for Radio Astronomy (ASTRON)
M. De Vos
Netherlands Institute for Radio Astronomy (ASTRON)
E. Van Der Wal
Netherlands Institute for Radio Astronomy (ASTRON)
R. van Weeren
Netherlands Institute for Radio Astronomy (ASTRON)
H. Weggemans
Netherlands Institute for Radio Astronomy (ASTRON)
P. Weltevrede
University of Manchester
S. White
Max Planck Society
S. J. Wijnholds
Netherlands Institute for Radio Astronomy (ASTRON)
T. Wilhelmsson
Max Planck Society
O. Wucknitz
University of Bonn
S. Yatawatta
University of Groningen
P.M. Zarka
LESIA - Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique
A.J. Zensus
Max Planck Society
J. E. van Zwieten
Netherlands Institute for Radio Astronomy (ASTRON)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 556 A2Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1051/0004-6361/201220873