The LOFAR Two-metre Sky Survey: Deep Fields Data Release 2 I. The ELAIS-N1 field
Journal article, 2025
We present the final 6 '' resolution data release of the ELAIS-N1 field from the LOw-Frequency ARray (LOFAR) Two-metre Sky Survey Deep Fields project (LoTSS Deep). The 144 MHz images are the most sensitive achieved to date at this frequency and were created from 290 TB of data obtained from 505 h on-source observations taken over 7.5 years. The data were processed following the strategies developed for previous LoTSS and LoTSS Deep data releases. The resulting images span 24.53 square degrees, and using a refined source detection approach, we identified 154 952 radio sources formed from 182 184 Gaussian components within this area. The maps reach a noise level of 10.7 mu Jy beam(-1) at 6 '' resolution, where approximately half of the noise is due to source confusion. In about 7.4% of the image, our limited dynamic range around bright sources results in a further > 5% increase in the noise. The images have a flux density scale accuracy of about 9%, and the standard deviation of offsets between our source positions and those from Pan-STARRS is 0.2 '' in RA and Dec for high significance detections. We searched individual epoch images for variable sources, identifying 39 objects with considerable variation. We also searched for circularly polarised sources, achieving three detections of previously known emitters (two stars and one pulsar) whilst constraining the typical polarisation fraction plus leakage to be less than 0.045%.
techniques: image processing
surveys
radio continuum: general
catalogs
Author
T. W. Shimwell
Netherlands Institute for Radio Astronomy (ASTRON)
Leiden University
C. L. Hale
University of Edinburgh
University of Oxford
P. N. Best
University of Edinburgh
A. Botteon
Istituto nazionale di astrofisica (INAF)
A. Drabent
Thüringer Landessternwarte Tautenburg
M. J. Hardcastle
University of Hertfordshire
V. Jelic
Ruder Boskovic Institute
J. M. G. H. J. de Jong
Leiden University
R. Kondapally
University of Edinburgh
H. J. A. Roettgering
Leiden University
C. Tasse
Rhodes University
Université Paris PSL
R. J. van Weeren
Leiden University
W. L. Williams
Jodrell Bank Observatory
A. Bonafede
Istituto nazionale di astrofisica (INAF)
University of Bologna
M. Bondi
Istituto nazionale di astrofisica (INAF)
M. Brueggen
University of Hamburg
G. Brunetti
Istituto nazionale di astrofisica (INAF)
J. R. Callingham
Netherlands Institute for Radio Astronomy (ASTRON)
Leiden University
F. De Gasperin
Istituto nazionale di astrofisica (INAF)
K. J. Duncan
University of Edinburgh
Cathy Horellou
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
S. Iyer
University of Amsterdam
I. de Ruiter
University of Amsterdam
K. Malek
National Centre for Nuclear Research
D. G. Nair
University of Concepcion
Max Planck Society
L. K. Morabito
Durham University
I. Prandoni
Istituto nazionale di astrofisica (INAF)
A. Rowlinson
University of Amsterdam
Netherlands Institute for Radio Astronomy (ASTRON)
A. Shulevski
University of Amsterdam
Netherlands Institute for Radio Astronomy (ASTRON)
University of Groningen
D. J. B. Smith
University of Hertfordshire
F. Sweijen
Durham University
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 695 A80Subject Categories (SSIF 2025)
Signal Processing
Astronomy, Astrophysics, and Cosmology
DOI
10.1051/0004-6361/202452930