LOFAR 150-MHz observations of the Bootes field: catalogue and source counts
Journal article, 2016
We present the first wide area (19 deg(2)), deep (a parts per thousand 120-150 mu Jy beam(-1)), high-resolution (5.6 x 7.4 arcsec) LOFAR High Band Antenna image of the Bootes field made at 130-169 MHz. This image is at least an order of magnitude deeper and 3-5 times higher in angular resolution than previously achieved for this field at low frequencies. The observations and data reduction, which includes full direction-dependent calibration, are described here. We present a radio source catalogue containing 6 276 sources detected over an area of 19 deg(2), with a peak flux density threshold of 5 sigma. As the first thorough test of the facet calibration strategy, introduced by van Weeren et al., we investigate the flux and positional accuracy of the catalogue. We present differential source counts that reach an order of magnitude deeper in flux density than previously achieved at these low frequencies, and show flattening at 150-MHz flux densities below 10 mJy associated with the rise of the low flux density star-forming galaxies and radio-quiet AGN.
techniques: interferometric
radio continuum: galaxies
surveys
galaxies: active
Author
W. L. Williams
Leiden University
University of Hertfordshire
Netherlands Institute for Radio Astronomy (ASTRON)
R. J. van Weeren
Harvard-Smithsonian Center for Astrophysics
H. Rottgering
Leiden University
P. Best
Royal Observatory
T. J. Dijkema
Netherlands Institute for Radio Astronomy (ASTRON)
F. De Gasperin
University of Hamburg
M. J. Hardcastle
University of Hertfordshire
G. Heald
University of Groningen
Netherlands Institute for Radio Astronomy (ASTRON)
I. Prandoni
INAF OAS Bologna
J. Sabater
Royal Observatory
T. W. Shimwell
Leiden University
C. Tasse
Paris Diderot University
I. van Bemmel
Joint Institute for VLBI in Europe (JIVE)
M. Brüggen
University of Hamburg
G. Brunetti
INAF OAS Bologna
John Conway
Chalmers, Earth and Space Sciences, Onsala Space Observatory
T.A. Enßlin
Max Planck Society
D. Engels
University of Hamburg
H. Falcke
Netherlands Institute for Radio Astronomy (ASTRON)
Radboud University
C. Ferrari
Observatoire de la Cote d'Azur
M. Haverkorn
Radboud University
Leiden University
N. Jackson
University of Manchester
M. J. Jarvis
University of Oxford
University of the Western Cape
A. D. Kapinska
University of Portsmouth
ARC Centre of Excellence for All-sky Astrophysics (CAASTRO)
University of Western Australia
E. Mahony
Netherlands Institute for Radio Astronomy (ASTRON)
G. K. Miley
Leiden University
L. K. Morabito
Leiden University
R. Morganti
Netherlands Institute for Radio Astronomy (ASTRON)
University of Groningen
E. Orru
Netherlands Institute for Radio Astronomy (ASTRON)
E. Retana-Montenegro
Leiden University
S. S. Sridhar
University of Groningen
Netherlands Institute for Radio Astronomy (ASTRON)
M. C. Toribio
Leiden University
G. J. White
Open University
STFC Rutherford Appleton Laboratory
M. W. Wise
Netherlands Institute for Radio Astronomy (ASTRON)
Anton Pannekoek Institute for Astronomy
J. T L Zwart
University of Cape Town
University of the Western Cape
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 460 3 2385-2412Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1093/mnras/stw1056