Observing pulsars and fast transients with LOFAR

¹ Jodrell Bank Center for Astrophysics, School of Physics and Astronomy, The University of Manchester, M13 9, PL Manchester, UK
e-mail: Ben.Stappers@manchester.ac.uk
² Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo, The Netherlands
³ Astronomical Institute “Anton Pannekoek”, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam, The Netherlands
⁴ Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK
⁵ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
⁶ School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ, UK
⁷ Max Planck Institute for Astrophysics, Karl Schwarzschild Str. 1, 85741 Garching, Germany
⁸ Department of Physics & Astronomy, Hicks Building, Hounsfield Road, Sheffield S3 7RH, UK
⁹ Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
¹⁰ Kapteyn Astronomical Institute, PO Box 800, 9700 AV Groningen, TheNetherlands
¹¹ Onsala Space Observatory, Dept. of Earth and Space Sciences, Chalmers University of Technology, SE-43992 Onsala, Sweden
¹² Department of Astrophysics/IMAPP, Radboud University Nijmegen, PO Box 9010, 6500 GL Nijmegen, The Netherlands
¹³ International Centre for Radio Astronomy Research – Curtin University, GPO Box U1987, Perth, WA 6845, Australia
¹⁴ STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX, UK
¹⁵ Institute for Astronomy, University of Edinburgh, Royal Observatory of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
¹⁶ LESIA, UMR CNRS 8109, Observatoire de Paris, 92195 Meudon, France
¹⁷ Argelander-Institut für Astronomie, University of Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
¹⁸ Leibniz-Institut fr Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
¹⁹ Thüringer Landessternwarte, Sternwarte 5, 07778 Tautenburg, Germany
²⁰ Astronomisches Institut der Ruhr-Universität Bochum, Universitaetsstrasse 150, 44780 Bochum, Germany
²¹ Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
²² Laboratoire de Physique et Chimie de l’Environnement et de l’Espace, CNRS/Université d’Orléans, France
²³ Center for Information Technology (CIT), University of Groningen, The Netherlands
²⁴ Radio Astronomy Lab, UC Berkeley, CA, USA
²⁵ Centre de Recherche Astrophysique de Lyon, Observatoire de Lyon, 9 Av. Charles André, 69561 Saint Genis Laval Cedex, France
²⁶ Mt Stromlo Observatory, Research School of Astronomy and Astrophysics, Australian National University, Weston, A.C.T. 2611, Australia

Received: 9 February 2011
Accepted: 22 March 2011

Abstract

Low frequency radio waves, while challenging to observe, are a rich source of information about pulsars. The LOw Frequency ARray (LOFAR) is a new radio interferometer operating in the lowest 4 octaves of the ionospheric “radio window”: 10–240 MHz, that will greatly facilitate observing pulsars at low radio frequencies. Through the huge collecting area, long baselines, and flexible digital hardware, it is expected that LOFAR will revolutionize radio astronomy at the lowest frequencies visible from Earth. LOFAR is a next-generation radio telescope and a pathfinder to the Square Kilometre Array (SKA), in that it incorporates advanced multi-beaming techniques between thousands of individual elements. We discuss the motivation for low-frequency pulsar observations in general and the potential of LOFAR in addressing these science goals. We present LOFAR as it is designed to perform high-time-resolution observations of pulsars and other fast transients, and outline the various relevant observing modes and data reduction pipelines that are already or will soon be implemented to facilitate these observations. A number of results obtained from commissioning observations are presented to demonstrate the exciting potential of the telescope. This paper outlines the case for low frequency pulsar observations and is also intended to serve as a reference for upcoming pulsar/fast transient science papers with LOFAR.