LOFAR/H-ATLAS: a deep low-frequency survey of the Herschel-ATLAS North Galactic Pole field
Journal article, 2016
We present Low-Frequency Array (LOFAR) High-Band Array observations of the Herschel-ATLAS North Galactic Pole survey area. The survey we have carried out, consisting of four pointings covering around 142 deg(2) of sky in the frequency range 126-173 MHz, does not provide uniform noise coverage but otherwise is representative of the quality of data to be expected in the planned LOFAR wide-area surveys, and has been reduced using recently developed 'facet calibration' methods at a resolution approaching the full resolution of the data sets (similar to 10 x 6 arcsec) and an rms off-source noise that ranges from 100 mu Jy beam(-1) in the centre of the best fields to around 2 mJy beam(-1) at the furthest extent of our imaging. We describe the imaging, cataloguing and source identification processes, and present some initial science results based on a 5 sigma source catalogue. These include (i) an initial look at the radio/far-infrared correlation at 150 MHz, showing that many Herschel sources are not yet detected by LOFAR; (ii) number counts at 150 MHz, including, for the first time, observational constraints on the numbers of star-forming galaxies; (iii) the 150-MHz luminosity functions for active and star-forming galaxies, which agree well with determinations at higher frequencies at low redshift, and show strong redshift evolution of the star-forming population; and (iv) some discussion of the implications of our observations for studies of radio galaxy life cycles.
galaxies
galaxies
less-than 1.0
sdss-iii
sky survey
star-formation history
mass-selected galaxies
science
function
forming galaxies
infrared-radio correlation
active
galaxies
luminosity
radio continuum
wide-field
demonstration phase
infrared
Author
M. J. Hardcastle
University of Hertfordshire
G. Gurkan
University of Hertfordshire
R. J. van Weeren
Harvard-Smithsonian Center for Astrophysics
W. L. Williams
University of Hertfordshire
P. N. Best
Royal Observatory
F. De Gasperin
Leiden University
D. Rafferty
University of Hamburg
S. C. Read
University of Hertfordshire
J. Sabater
Royal Observatory
T. W. Shimwell
Leiden University
D. J. B. Smith
University of Hertfordshire
C. Tasse
Paris Diderot University
N. Bourne
Royal Observatory
M. Brienza
University of Groningen
Netherlands Institute for Radio Astronomy (ASTRON)
M. Brüggen
University of Hamburg
G. Brunetti
INAF OAS Bologna
K.T. Chyz̊y
Jagiellonian University in Kraków
John Conway
Chalmers, Earth and Space Sciences, Onsala Space Observatory
L. Dunne
Cardiff University
Royal Observatory
S. Eales
Jagiellonian University in Kraków
S. J. Maddox
Royal Observatory
Cardiff University
M. J. Jarvis
University of Oxford
University of the Western Cape
E. Mahony
ARC Centre of Excellence for All-sky Astrophysics (CAASTRO)
The University of Sydney
R. Morganti
University of Groningen
Netherlands Institute for Radio Astronomy (ASTRON)
I. Prandoni
INAF OAS Bologna
H. Rottgering
Leiden University
E. Valiante
Cardiff University
G. J. White
Open University
STFC Rutherford Appleton Laboratory
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 462 2 1910-1936Subject Categories
Astronomy, Astrophysics and Cosmology
Infrastructure
Onsala Space Observatory
DOI
10.1093/mnras/stw1763