Characterising the Apertif primary beam response
Journal article, 2022

Context. Phased array feeds (PAFs) are multi-element receivers in the focal plane of a telescope that make it possible to simultaneously form multiple beams on the sky by combining the complex gains of the individual antenna elements. Recently, the Westerbork Synthesis Radio Telescope (WSRT) was upgraded with PAF receivers to carry out several observing programs, including two imaging surveys and a time-domain survey. The Apertif imaging surveys use a configuration of 40 partially overlapping compound beams (CBs) simultaneously formed on the sky and arranged in an approximately rectangular shape. Aims. This work is aimed at characterising the response of the 40 Apertif CBs to create frequency-resolved I, XX, and YY polarization empirical beam shapes. The measured CB maps can be used for the image deconvolution, primary beam correction, and mosaicking processes of Apertif imaging data. Methods. We used drift scan measurements to measure the response of each of the 40 Apertif CBs. We derived beam maps for all individual beams in I, XX, and YY polarisation in 10 or 18 frequency bins over the same bandwidth as the Apertif imaging surveys. We sampled the main lobe of the beams and the side lobes up to a radius of 0.6 degrees from the beam centres. In addition, we derived beam maps for each individual WSRT dish. Results. We present the frequency and time dependence of the beam shapes and sizes. We compared the compound beam shapes derived with the drift scan method to beam shapes derived with an independent method using a Gaussian Process Regression comparison between the Apertif continuum images and the NRAO VLA Sky Survey (NVSS) catalogue. We find a good agreement between the beam shapes derived with the two independent methods.

instrumentation

methods

telescopes

surveys

detectors

observational

interferometers

instrumentation

Author

H. Denes

Netherlands Institute for Radio Astronomy (ASTRON)

K. M. Hess

Spanish National Research Council (CSIC)

University of Groningen

Netherlands Institute for Radio Astronomy (ASTRON)

E. A. K. Adams

University of Groningen

Netherlands Institute for Radio Astronomy (ASTRON)

A. Kutkin

Netherlands Institute for Radio Astronomy (ASTRON)

Russian Academy of Sciences

R. Morganti

University of Groningen

Netherlands Institute for Radio Astronomy (ASTRON)

J. M. van der Hulst

University of Groningen

T. A. Oosterloo

Netherlands Institute for Radio Astronomy (ASTRON)

University of Groningen

V. A. Moss

The University of Sydney

Commonwealth Scientific and Industrial Research Organisation (CSIRO)

Netherlands Institute for Radio Astronomy (ASTRON)

B. Adebahr

Ruhr-Universität Bochum

W. J. G. de Blok

University of Groningen

University of Cape Town

Netherlands Institute for Radio Astronomy (ASTRON)

Marianna Ivashina

Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks

A. H. W. M. Coolen

Netherlands Institute for Radio Astronomy (ASTRON)

S. Damstra

Netherlands Institute for Radio Astronomy (ASTRON)

B. Hut

Netherlands Institute for Radio Astronomy (ASTRON)

G. M. Loose

Netherlands Institute for Radio Astronomy (ASTRON)

D. M. Lucero

Virginia Polytechnic Institute and State University

Y. Maan

Netherlands Institute for Radio Astronomy (ASTRON)

Tata Institute of Fundamental Research

A. Mika

Netherlands Institute for Radio Astronomy (ASTRON)

M. J. Norden

Netherlands Institute for Radio Astronomy (ASTRON)

L. C. Oostrum

University of Amsterdam

Netherlands eScience Center

Netherlands Institute for Radio Astronomy (ASTRON)

D. J. Pisano

University of Cape Town

West Virginia University

R. Smits

Netherlands Institute for Radio Astronomy (ASTRON)

W. A. van Cappellen

Netherlands Institute for Radio Astronomy (ASTRON)

R. van den Brink

Netherlands Institute for Radio Astronomy (ASTRON)

Tricas Industrial Design & Engineering

D. van der Schuur

Netherlands Institute for Radio Astronomy (ASTRON)

G. N. J. van Diepen

Netherlands Institute for Radio Astronomy (ASTRON)

J. van Leeuwen

University of Amsterdam

Netherlands Institute for Radio Astronomy (ASTRON)

D. Vohl

Netherlands Institute for Radio Astronomy (ASTRON)

University of Amsterdam

S. J. Wijnholds

Netherlands Institute for Radio Astronomy (ASTRON)

J. Ziemke

University of Oslo

Netherlands Institute for Radio Astronomy (ASTRON)

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 667 A40

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

Radiology, Nuclear Medicine and Medical Imaging

DOI

10.1051/0004-6361/202244045

More information

Latest update

10/10/2023