The LOFAR Two-metre Sky Survey
Astronomy and Astrophysics, vol. 659, pp. A1
Abstract
In this data release from the ongoing LOw-Frequency ARray (LOFAR) Two-metre Sky Survey we present 120–168 MHz images covering 27% of the northern sky. Our coverage is split into two regions centred at approximately 12h45m +44°30′ and 1h00m +28°00′ and spanning 4178 and 1457 square degrees respectively. The images were derived from 3451 h (7.6 PB) of LOFAR High Band Antenna data which were corrected for the direction-independent instrumental properties as well as direction-dependent ionospheric distortions during extensive, but fully automated, data processing. A catalogue of 4 396 228 radio sources is derived from our total intensity (Stokes I) maps, where the majority of these have never been detected at radio wavelengths before. At 6″ resolution, our full bandwidth Stokes I continuum maps with a central frequency of 144 MHz have: a median rms sensitivity of 83 μJy beam−1; a flux density scale accuracy of approximately 10%; an astrometric accuracy of 0.2″; and we estimate the point-source completeness to be 90% at a peak brightness of 0.8 mJy beam−1. By creating three 16 MHz bandwidth images across the band we are able to measure the in-band spectral index of many sources, albeit with an error on the derived spectral index of > ± 0.2 which is a consequence of our flux-density scale accuracy and small fractional bandwidth. Our circular polarisation (Stokes V) 20″ resolution 120–168 MHz continuum images have a median rms sensitivity of 95 μJy beam−1, and we estimate a Stokes I to Stokes V leakage of 0.056%. Our linear polarisation (Stokes Q and Stokes U) image cubes consist of 480 × 97.6 kHz wide planes and have a median rms sensitivity per plane of 10.8 mJy beam−1 at 4′ and 2.2 mJy beam−1 at 20″; we estimate the Stokes I to Stokes Q/U leakage to be approximately 0.2%. Here we characterise and publicly release our Stokes I, Q, U and V images in addition to the calibrated uv-data to facilitate the thorough scientific exploitation of this unique dataset.
Authors 100
-
Leiden University · Leiden Observatory · Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Affiliation as printed
Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK
-
Centre National de la Recherche Scientifique · Rhodes University · Université Paris Sciences et Lettres · Observatoire de Paris · Galaxies, Etoiles, Physique et Instrumentation
Affiliation as printed
Department of Physics & Electronics, Rhodes University, PO Box 94 Grahamstown 6140, South Africa
GEPI, Observatoire de Paris, Université PSL, CNRS, 5 place Jules Janssen, 92190 Meudon, France
-
Royal Observatory · University of Edinburgh
Affiliation as printed
School of Physics and Astronomy, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, EH9 3HJ Edinburgh, UK
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Thüringer Landessternwarte Tautenburg
Affiliation as printed
Thüringer Landessternwarte, Sternwarte 5, 07778 Tautenburg, Germany
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Rhodes University · South African Radio Astronomy Observatory
Affiliation as printed
Department of Physics & Electronics, Rhodes University, PO Box 94 Grahamstown 6140, South Africa
South African Radio Astronomy Observatory (SARAO), 2 Fir Street, Black River Business Park, Observatory, Cape Town, South Africa
-
Affiliation as printed
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
-
Istituto di Radioastronomia di Bologna · National Institute for Astrophysics
Affiliation as printed
INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
-
Leiden University · Leiden Observatory · Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Affiliation as printed
Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Kraków, Poland
-
Chalmers University of Technology
Affiliation as printed
Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
-
Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
-
Royal Observatory · University of Edinburgh
Affiliation as printed
School of Physics and Astronomy, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, EH9 3HJ Edinburgh, UK
-
Affiliation as printed
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
-
Royal Observatory · University of Edinburgh
Affiliation as printed
School of Physics and Astronomy, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, EH9 3HJ Edinburgh, UK
-
Affiliation as printed
Department of Astrophysics/IMAPP, Radboud University Nijmegen, PO Box 9010 6500 GL Nijmegen, The Netherlands
-
Rhodes University · South African Radio Astronomy Observatory
Affiliation as printed
Department of Physics & Electronics, Rhodes University, PO Box 94 Grahamstown 6140, South Africa
South African Radio Astronomy Observatory (SARAO), 2 Fir Street, Black River Business Park, Observatory, Cape Town, South Africa
-
Affiliation as printed
Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
-
Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Affiliation as printed
Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham DH1 3LE, UK
Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
-
University of Groningen · Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
Kapteyn Astronomical Institute, University of Groningen, PO Box 800 9700 AV Groningen, The Netherlands
-
University of Groningen · Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
Kapteyn Astronomical Institute, University of Groningen, PO Box 800 9700 AV Groningen, The Netherlands
-
Leiden University · Leiden Observatory · Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
SURF, PO Box 94613 1090 GP Amsterdam, The Netherlands
-
Affiliation as printed
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
-
Royal Observatory · University of Edinburgh
Affiliation as printed
School of Physics and Astronomy, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, EH9 3HJ Edinburgh, UK
-
Affiliation as printed
Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK
-
Affiliation as printed
Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany
-
Rhodes University · South African Radio Astronomy Observatory
Affiliation as printed
Department of Physics & Electronics, Rhodes University, PO Box 94 Grahamstown 6140, South Africa
South African Radio Astronomy Observatory (SARAO), 2 Fir Street, Black River Business Park, Observatory, Cape Town, South Africa
-
Affiliation as printed
School of Physical Sciences and Centre for Astrophysics & Relativity, Dublin City University, Glasnevin D09 W6Y4, Ireland
-
University of Groningen · Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
Kapteyn Astronomical Institute, University of Groningen, PO Box 800 9700 AV Groningen, The Netherlands
-
Rutherford Appleton Laboratory · The Open University
Affiliation as printed
RAL Space, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, UK
School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Royal Observatory · University of Edinburgh
Affiliation as printed
School of Physics and Astronomy, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, EH9 3HJ Edinburgh, UK
-
Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
-
Affiliation as printed
Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX, UK
-
Universität Hamburg · Istituto di Radioastronomia di Bologna · National Institute for Astrophysics · University of Bologna
Affiliation as printed
DIFA – Universitá di Bologna, via Gobetti 93/2, 40129 Bologna, Italy
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
-
Affiliation as printed
DIFA – Universitá di Bologna, via Gobetti 93/2, 40129 Bologna, Italy
-
Istituto di Radioastronomia di Bologna · National Institute for Astrophysics · University of Bologna
Affiliation as printed
DIFA – Universitá di Bologna, via Gobetti 93/2, 40129 Bologna, Italy
INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
-
Center for Theoretical Physics · Polish Academy of Sciences
Affiliation as printed
Center for Theoretical Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
-
Istituto di Radioastronomia di Bologna · Osservatorio Astronomico di Padova · National Institute for Astrophysics
Affiliation as printed
INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy
Italian ALMA Regional Centre, Via Gobetti 101, 40129 Bologna, Italy
INAF-Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy
-
Affiliation as printed
European Southern Observatory, Karl-Schwarzchild-Strasse 2, 85748 Garching bei München, Germany
-
Istituto di Radioastronomia di Bologna · National Institute for Astrophysics
Affiliation as printed
INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
-
Center for Astrophysics Harvard & Smithsonian
Affiliation as printed
Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138, USA
-
Affiliation as printed
School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
-
Affiliation as printed
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
-
Istituto di Radioastronomia di Bologna · National Institute for Astrophysics · University of Bologna
Affiliation as printed
DIFA – Universitá di Bologna, via Gobetti 93/2, 40129 Bologna, Italy
INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
-
Affiliation as printed
SURF, PO Box 94613 1090 GP Amsterdam, The Netherlands
-
Affiliation as printed
Ruhr University Bochum, Faculty of Physics and Astronomy, Astronomical Institute, 44780 Bochum, Germany
-
Affiliation as printed
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
-
Affiliation as printed
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
-
Max Planck Institute for Astrophysics · Ludwig-Maximilians-Universität München
Affiliation as printed
Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 Munich, Germany
Max Planck Institute for Astrophysics, Karl-Schwarzschild Str. 1, 85748 Garching, Germany
-
National Radio Astronomy Observatory
Affiliation as printed
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
-
Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
-
Thüringer Landessternwarte Tautenburg
Affiliation as printed
Thüringer Landessternwarte, Sternwarte 5, 07778 Tautenburg, Germany
-
Radboud University Nijmegen · University of Warmia and Mazury in Olsztyn
Affiliation as printed
Department of Astrophysics/IMAPP, Radboud University Nijmegen, PO Box 9010 6500 GL Nijmegen, The Netherlands
Space Radio-Diagnostics Research Centre, University of Warmia and Mazury, ul. Oczapowskiego 2, 10-719 Olsztyn, Poland
-
Commonwealth Scientific and Industrial Research Organisation
Affiliation as printed
CSIRO Space & Astronomy, PO Box 1130 Bentley, WA 6102, Australia
-
Affiliation as printed
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
-
Affiliation as printed
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
-
Thüringer Landessternwarte Tautenburg
Affiliation as printed
Thüringer Landessternwarte, Sternwarte 5, 07778 Tautenburg, Germany
-
Chalmers University of Technology
Affiliation as printed
Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
-
Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
-
Affiliation as printed
Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Kraków, Poland
-
Affiliation as printed
Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
-
Royal Observatory · University of Edinburgh
Affiliation as printed
School of Physics and Astronomy, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, EH9 3HJ Edinburgh, UK
-
University of Groningen · Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
Kapteyn Astronomical Institute, University of Groningen, PO Box 800 9700 AV Groningen, The Netherlands
-
Nicolaus Copernicus University
Affiliation as printed
Institute of Astronomy, Faculty of Physics, Astronomy and Informatics, NCU, Grudziadzka 5, 87-100 Toruń, Poland
-
National Institute for Astrophysics
Affiliation as printed
INAF – IAPS, Via Fosso del Cavaliere 100, 00133 Roma, Italy
-
Thüringer Landessternwarte Tautenburg
Affiliation as printed
Thüringer Landessternwarte, Sternwarte 5, 07778 Tautenburg, Germany
-
Centre National de la Recherche Scientifique · Aix-Marseille Université · National Centre for Nuclear Research
Affiliation as printed
Aix Marseille Univ. CNRS, CNES, LAM, Marseille, France
National Centre for Nuclear Research, ul. Pasteura 7, 02-093 Warszawa, Poland
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Osservatorio Astrofisico di Torino · Consorzio Interuniversitario Fisica Spaziale · University of Turin
Affiliation as printed
Consorzio Interuniversitario per la Fisica Spaziale, via Pietro Giuria 1, 10125 Torino, Italy
Dipartimento di Fisica, Università degli Studi di Torino, via Pietro Giuria 1, 10125 Torino, Italy
INAF-Osservatorio Astrofisico di Torino, via Osservatorio 20, 10025 Pino Torinese, Italy
-
Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
-
Affiliation as printed
School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
-
Leiden University · Leiden Observatory · Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Affiliation as printed
Joint Institute for VLBI ERIC, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
-
National Centre for Nuclear Research
Affiliation as printed
National Centre for Nuclear Research, Astrophysics Division, ul. Pasteura 7, 02-093 Warsaw, Poland
-
Affiliation as printed
Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Kraków, Poland
-
Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
-
Affiliation as printed
Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Kraków, Poland
-
Affiliation as printed
Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
-
Istituto di Radioastronomia di Bologna · National Institute for Astrophysics
Affiliation as printed
INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
-
Affiliation as printed
SURF, PO Box 94613 1090 GP Amsterdam, The Netherlands
-
Istituto di Radioastronomia di Bologna · National Institute for Astrophysics · University of Bologna
Affiliation as printed
DIFA – Universitá di Bologna, via Gobetti 93/2, 40129 Bologna, Italy
INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
-
Affiliation as printed
Astrophysics Research Centre, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
School of Mathematics, Statistics, & Computer Science, University of KwaZulu-Natal, Durban, South Africa
-
Commonwealth Scientific and Industrial Research Organisation · Istituto di Radioastronomia di Bologna · National Institute for Astrophysics · University of Bologna
Affiliation as printed
CSIRO Space & Astronomy, PO Box 1130 Bentley, WA 6102, Australia
DIFA – Universitá di Bologna, via Gobetti 93/2, 40129 Bologna, Italy
INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
-
University of Amsterdam · Netherlands Institute for Radio Astronomy
Affiliation as printed
ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
Anton Pannekoek Institute, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam, The Netherlands
-
Affiliation as printed
Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
-
Affiliation as printed
SURF, PO Box 94613 1090 GP Amsterdam, The Netherlands
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
-
Affiliation as printed
Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany
-
Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
Cited by 490 stored of 491
No patents citing this paper on Lens.org (checked 2026-10-11).