The LOFAR Two-metre Sky Survey: VII. Third Data Release
Journal article, 2026
We present the third data release of the LOFAR Two-metre Sky Survey (LoTSS-DR3). The survey images cover 88% of the northern sky and were created from 12 950 h of data (18.6 PB) accumulated over 10.5 years. Producing the images took 20 million core hours of processing through direction-independent and direction-dependent calibration pipelines that correct for instrumental effects as well as spatially and temporally varying ionospheric distortions. In our 120–168 MHz continuum mosaic images with an angular resolution of 600 (900 below declination 10◦) we catalogue 13 667 877 sources, formed from 16 943 656 Gaussian components. The scatter in the astrometric precision approximately follows the expected noise-like behaviour but with an additional systematic component of at least 0.2400 that is likely due to calibration imperfections. The random flux density scale error is 6%, while the systematic offset was previously shown to be within 2%. The median sensitivity of our mosaics is 92 µJy beam−1, improving to 68 µJy beam−1 at high observing elevations, but degrading to 183 µJy beam−1 at the celestial equator due to station area projection effects. Completeness simulations, accounting for realistic source models, time- and bandwidth-smearing effects, and astrometric errors, indicate that we detect more than 95% of compact sources with integrated flux densities exceeding 9 times the local root mean square (RMS) noise. However, the recovered source counts in a particular integrated flux density bin do not match the injected counts until flux densities exceed 45 times the local RMS noise. The Euclidean-normalised differential source counts derived from the survey constrain the radio source population over five orders of magnitude and are in good agreement with previous deep and wide-area surveys. All data products are publicly available, including catalogues, individual-field Stokes I, Q, U, and V images, mosaicked Stokes I images, and uv data with associated direction-dependent calibration solutions.
radio continuum: general
surveys
catalogs
instrumentation: interferometers
Author
T. W. Shimwell
Netherlands Institute for Radio Astronomy (ASTRON)
M. J. Hardcastle
University of Hertfordshire
C. Tasse
Paris Observatory
A. Drabent
Thüringer Landessternwarte Tautenburg
A. Botteon
Istituto di Radioastronomia
W. L. Williams
SKA Organisation
P.N. Best
University of Edinburgh
H. Rottgering
Leiden University
M. Brueggen
University of Hamburg
G. Brunetti
Istituto di Radioastronomia
J. R. Callingham
Netherlands Institute for Radio Astronomy (ASTRON)
K.T. Chyz̊y
Jagiellonian University in Kraków
John Conway
Chalmers, Space, Earth and Environment, Onsala Space Observatory
F. De Gasperin
Istituto di Radioastronomia
M. Haverkorn
Radboud University
Cathy Horellou
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
N. Jackson
University of Manchester
G. Miley
Leiden University
L. Morabito
Durham University
R. Morganti
Netherlands Institute for Radio Astronomy (ASTRON)
S. P. O’Sullivan
Complutense University
D. J. Schwarz
Bielefeld University
D. J.B. Smith
University of Hertfordshire
R. van Weeren
Leiden University
Harish K. Vedantham
Netherlands Institute for Radio Astronomy (ASTRON)
G. White
The Open University
A. Ahmadi
Netherlands Institute for Radio Astronomy (ASTRON)
L. Alegre
University of Hertfordshire
M. Arias
Netherlands Institute for Radio Astronomy (ASTRON)
B. Asabere
Netherlands Institute for Radio Astronomy (ASTRON)
B. Bahr-Kalus
Istituto nazionale di astrofisica (INAF)
B. Barkus
University of Hertfordshire
M. Bilicki
Polish Academy of Sciences
L. Böhme
Bielefeld University
M. Brentjens
Netherlands Institute for Radio Astronomy (ASTRON)
M. Brienza
Istituto di Radioastronomia
D. Bomans
Ruhr-Universität Bochum
A. Bonafede
Istituto di Radioastronomia
M. Bonato
Istituto di Radioastronomia
E. Bonnassieux
University of Bordeaux
J.M. Boxelaar
Istituto di Radioastronomia
S. Camera
Istituto nazionale di astrofisica (INAF)
R. Cassano
Istituto di Radioastronomia
J. Chilufya
University of Hertfordshire
M. Cianfaglione
Istituto di Radioastronomia
J. H. Croston
The Open University
V. Cuciti
Istituto di Radioastronomia
P. Dabhade
Narodowe Centrum Badan Jadrowych
E. De Rubeis
Istituto di Radioastronomia
J.M.G.H.J. de Jong
Netherlands Institute for Radio Astronomy (ASTRON)
D. Dallacasa
Istituto di Radioastronomia
R. -J. Dettmar
Ruhr-Universität Bochum
K. Duncan
University of Edinburgh
G. Di Gennaro
Istituto di Radioastronomia
H.W. Edler
Netherlands Institute for Radio Astronomy (ASTRON)
C. Groeneveld
Istituto di Radioastronomia
G. Gurkan
University of Hertfordshire
M. Hajduk
University of Warmia and Mazury in Olsztyn
C. Hale
University of Edinburgh
V. Heesen
University of Hamburg
D. N. Hoang
Thüringer Landessternwarte Tautenburg
M. Hoeft
Thüringer Landessternwarte Tautenburg
H. Holties
Netherlands Institute for Radio Astronomy (ASTRON)
M.A. Horton
University of Cambridge
M. Iacobelli
Netherlands Institute for Radio Astronomy (ASTRON)
M. Jamrozy
Jagiellonian University in Kraków
M.J. Jarvis
University of Oxford
V. Jelić
Ruder Boskovic Institute
M. Kadler
University of Würzburg
R. Kondapally
Durham University
M. Kunert-Bajraszewska
Nicolaus Copernicus University (SGMK)
M. Loose
Netherlands Institute for Radio Astronomy (ASTRON)
M. Magliocchetti
Istituto nazionale di astrofisica (INAF)
K. Malek
Narodowe Centrum Badan Jadrowych
C. Manzano
Jülich Research Centre
J. McKean
University of Groningen
M. Mevius
Netherlands Institute for Radio Astronomy (ASTRON)
B. Mingo
University of Hertfordshire
A. Miskolczi
Jülich Research Centre
A. Misra
Jagiellonian University in Kraków
J. Moldon
Spanish National Research Council (CSIC)
Dhanya G. Nair
University of Concepcion
S.J. Nakoneczny
Polish Academy of Sciences
E. Orrú
Netherlands Institute for Radio Astronomy (ASTRON)
M. Pashapour-Ahmadabadi
Bielefeld University
T. Pasini
Istituto di Radioastronomia
J. Petley
Leiden University
J.C.S. Pierce
University of Hertfordshire
I. Prandoni
Istituto di Radioastronomia
D. Rafferty
University of Hamburg
K. Rajpurohit
Harvard-Smithsonian Center for Astrophysics
C. J. Riseley
Ruhr-Universität Bochum
I.D. Roberts
University of Waterloo
S. Sethi
Jagiellonian University in Kraków
A. Shulevski
Netherlands Institute for Radio Astronomy (ASTRON)
M. Stein
Ruhr-Universität Bochum
C. Stuardi
Istituto di Radioastronomia
F. Sweijen
Durham University
S. ter Veen
Netherlands Institute for Radio Astronomy (ASTRON)
R. Timmerman
Durham University
M. Vaccari
Istituto di Radioastronomia
S. J. Wijnholds
Netherlands Institute for Radio Astronomy (ASTRON)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 707 A198Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.1051/0004-6361/202557749