LOFAR: The LOw-Frequency ARray
read the original abstract
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.
This paper has not been read by Pith yet.
Forward citations
Cited by 25 Pith papers
-
Polarisation and Faraday rotation measure imaging at metre wavelengths with sub-arcsecond resolution: a foundational calibration strategy
A calibration strategy using full-Jones corrections with an in-field unpolarised calibrator and visibility-based multi-epoch alignment enables sub-arcsecond polarimetric imaging with LOFAR at metre wavelengths.
-
Detection of a parsec-scale, compact, and fading ejecta from an accreting massive black hole
VLBI at 4.9 GHz plus multi-epoch survey data reveal a fading parsec-scale radio component near the optical center of a dwarf galaxy, interpreted as transient ejecta from IMBH accretion.
-
Imaging spectroscopy reveals spike-like repeating radio burst pairs in the solar corona
Detection and characterization of 613 repeating radio burst pairs in the solar corona at 30-50 MHz, with delayed components interpreted as turbulent echoes of harmonic emission via imaging spectroscopy and propagation...
-
Nearest Neighbour-Based Statistics for 21cm-Galaxy Cross-Correlations in the Epoch of Reionization
kNN CDF statistics detect 21cm-galaxy cross-correlations more effectively than two-point methods and distinguish reionization models at fixed ionized fraction even with noise and foregrounds.
-
Towards improved synchrotron self absorption energy estimates: accounting for inhomogeneous and non-spherical emitting regions
This paper derives quantitative correction factors for traditional SSA minimum energy estimates to account for inhomogeneity and non-spherical geometry in emitting regions.
-
21cmEMUv3: a hybrid diffusion-LSTM emulator of 21cmFAST summary observables
21cmEMUv3 emulates the cylindrical 21cm power spectrum via score-based diffusion and six other 21cmFAST observables via LSTM networks at sub-percent accuracy, then uses the emulator to infer a lower limit on soft-band...
-
A Designer's Guide to Lunar Far-Side Interferometer Array: Power Spectrum Measurement and Cosmological Constraints from the Dark Ages
A lunar array needs at least ~30,000 Fourier modes and distributed stations to reach σ(α_s)=0.034 on inflation, competitive with Planck, though thermal noise limits high-redshift small-scale access.
-
Imaging spectroscopy reveals spike-like repeating radio burst pairs in the solar corona
Imaging spectroscopy identifies repeating solar radio burst pairs whose delayed components are interpreted as turbulent echoes of harmonic emission in anisotropic coronal plasma.
-
The ultra low-frequency spectral properties of bright extended radio galaxies in the 3CRR catalogue
Presents ultra-low frequency spectral index maps for 22 bright extended radio galaxies showing indices of ~0.5 near cores rising to >1.0 in lobes for FR I sources and 0.5-0.9 in FR II hotspots.
-
Mitigating residual foregrounds and systematic errors in SKA1-Low AA* EoR observations via Bayesian Gaussian Process Regression
Bayesian GPR recovers the 21cm signal within 2σ credible intervals for most k-modes (0.06 to 1.0 h/Mpc) in SKA1-Low simulations that include realistic residual foregrounds and systematics.
-
Role of SKA in Advancing Remote Measurements of Magnetic Fields of Solar Coronal Mass Ejections
SKA's higher sensitivity and bandwidth will enable fuller exploitation of radio methods for measuring CME magnetic fields and improving space weather predictions.
-
Measuring High-Energy Cosmic Particles with the SKA
SKA-Low is projected to reconstruct cosmic-ray air-shower depth of maximum with better than 8 g/cm² resolution and enable full reconstruction down to PeV energies via radio detection.
-
Early phases of star formation with SKAO: synchrotron emission from dense starless cores in molecular clouds
SKAO will enable detection of synchrotron emission from prestellar cores to probe their magnetic field properties in nearby star-forming regions.
-
Tracing Large-scale Structure with the MeerKLASS On-the-Fly Survey: Angular Clustering of Radio Sources at 816 MHz
First measurement of angular clustering w(theta) for radio sources at 816 MHz over 800 deg2 yields positive signal and effective bias 1.53-2.0 depending on N(z) prior.
-
PEARLS: JWST Counterparts of Micro-Jy Radio Sources in the NEP Time Domain Field. II. All Four Spokes
JWST finds infrared counterparts for nearly all micro-Jy radio sources, with star formation explaining the radio output in roughly 79% of cases after accounting for non-linear luminosity relations.
-
Probing Primordial Black Holes with upcoming Radio Telescopes: a case study for LOFAR2.0, FAST Core Array and BINGO
LOFAR2.0, FAST Core Array and BINGO can constrain the PBH dark matter fraction f_PBH below 0.16-0.39 for masses above 10^{-2} to 10 solar masses via FRB lensing statistics.
-
Mitigating gain calibration errors from EoR observations with SKA1-Low AA*
Simulations show hybrid foreground mitigation (GPR + PCA combined with avoidance) recovers the HI 21cm signal within 2σ for gain calibration errors ≤1% in SKA1-Low AA* observations over 0.05-0.5 Mpc^{-1} scales.
-
Hunting for extreme high-energy-peaked BL Lacs: Rare to find and difficult to classify
Follow-up observations reclassify 7 of 10 candidate ultra extreme high-energy-peaked BL Lacs as AGNs, with only 2 possibly compatible with MeV-peaked SEDs.
-
A Non-Negativity Iterative Approach to Image Deconvolution for SKA
Presents a non-negativity constrained iterative deconvolution method for SKA radio images that is fast and performs well on simulated point and extended sources in noise-free conditions.
-
Cosmology from Clustering of Continuum Galaxies
Forecasts angular clustering for a 20,000 sq deg SKAO radio continuum survey reaching O(300-400 million) sources and discusses needed corrections for telescope systematics and population modeling.
-
The Murchison Widefield Array Phase III upgrade: Sensitivity Doubled, Number of Baselines Quadrupled, Flexibility Enhanced, and EoR Observations Optimised
MWA Phase III upgrade adds receivers and uses MWAX correlator to support full 256-tile correlation, doubling sensitivity and quadrupling baselines.
-
Radio Wave Propagation as a Probe of the Solar Corona and Solar Wind
Radio wave distortion effects serve as established probes of solar corona and wind turbulence parameters, with SKA expected to expand observational capabilities.
-
SKAO and Gamma-Ray Synergies
Overview of synergies between SKA radio observations and gamma-ray facilities for studying transient, variable, and steady GeV-TeV sources.
-
AGN Jets from Formation to Dissipation
The chapter summarizes gaps in AGN jet research and projects how SKA standalone and combined observations will address jet-host galaxy co-evolution across scales.
-
Axions as Dark Matter, Dark Energy, and Dark Radiation
A mini-review of axion phenomenology showing how light bosons can account for dark matter, drive cosmic acceleration, or contribute to relativistic backgrounds in the early and late Universe.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.