Journal articles

Wide-band, low-frequency pulse profiles of 100 radio pulsars with LOFAR

M. Pilia ¹ J.W.T. J Hessels ¹ B.W W Stappers ² V.I. Kondratiev ¹ M M Kramer ³ J J van Leeuwen ⁴ P P Weltevrede ² A G Lyne ² K Zagkouris ⁵ T.E. E Hassall ⁶ A.V. A Bilous ⁷ R.P. P Breton ⁶ H Falcke ¹ Jean-Mathias Griessmeier ^{8, 9} E E Keane ¹⁰ A A Karastergiou ¹¹ M M Kuniyoshi ¹² A A Noutsos ¹² S. Osłowski ¹³ M. M Serylak ¹⁴ C. C Sobey ¹ S V ter Veen ¹ A A Alexov ¹⁵ A J Anderson ¹⁶ A A Asgekar ¹ A A Avruch ¹⁷ M E Bell ¹⁸ M J Bentum ¹ G G Bernardi ¹⁹ L. Bîrzan ²⁰ A A Bonafede ²¹ B Breitling ²² J J Broderick ⁵ M M Brüggen ²³ C C Ciardi ²⁴ Stéphane C Corbel ^{25, 9} D D de Geus ¹ A J de Jong ²⁶ A D Deller ¹ S D Duscha ¹ J J Eislöffel ²⁷ R A Fallows ²⁸ R Fender ²⁹ C C Ferrari ³⁰ W W Frieswijk ¹ M.A G Garrett ¹ A G Gunst ¹ J.P. J Hamaker ¹ H G Heald ¹ A A Horneffer ¹² P J Jonker ¹⁷ J J Juette ³¹ G G Kuper ¹ P P Maat ¹ M G Mann ³² S M Markoff ⁴ R M Mcfadden ¹ D. D Mckay-Bukowski ³³ C J Miller-Jones ³⁴ A A Nelles ³⁵ H. P Paas ³⁶ M P Pandey-Pommier ³⁷ M. P Pietka ⁵ P P Pizzo ¹ P G Polatidis ³⁷ R W Reich ¹² R Röttgering ²⁰ A. A Rowlinson ³⁸ S D Schwarz ³⁹ O Smirnov ⁴⁰ S M Steinmetz ⁴¹ S A Stewart ⁴² S J Swinbank ⁴³ Michel Tagger ⁸ Y Tang ⁴⁴ C C Tasse ⁴⁵ S Thoudam ⁴⁶ C C Toribio ¹ A J van Der Horst ⁴ R V Vermeulen ¹ C C Vocks ³² R J van Weeren ¹⁷ R.A.M.J Wijers ⁴⁷ R W Wijnands ⁴ S J Wijnholds ¹ O W Wucknitz ⁴⁸ P P Zarka ⁴⁵

1 ASTRON - Netherlands Institute for Radio Astronomy

2 Jodrell Bank Centre for Astrophysics

3 VUMC - Vrije Universiteit Medical Centre

4 AI PANNEKOEK - Astronomical Institute Anton Pannekoek

5 Oxford Astrophysics

6 School of Physics and Astronomy [Southampton]

7 IMAPP - Institute for Mathematics, Astrophysics and Particle Physics

8 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace

9 USN - Unité Scientifique de la Station de Nançay

10 CAS - Centre for Astrophysics and Supercomputing [Swinburne]

11 Department of Physics [Oxford]

12 MPIFR - Max-Planck-Institut für Radioastronomie

13 Universität Bielefeld = Bielefeld University

14 University of Cape Town

15 STSci - Space Telescope Science Institute

16 Epidémiologie et Biostatistique [Bordeaux]

17 SRON - SRON Netherlands Institute for Space Research

18 University of Southampton

19 CfA - Harvard-Smithsonian Center for Astrophysics

20 Leiden Observatory [Leiden]

21 University of Hamburg

22 DSMZ - Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH / Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures

23 University of Edinburgh

24 MPA - Max-Planck-Institut für Astrophysik

25 AIM (UMR_7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation

26 Structural Dynamics and Acoustics

27 TLS - Thüringer Landessternwarte Tautenburg

28 Institute of Mathematical and Physical Sciences

29 Department of Astrophysics [Oxford]

30 Département de Géologie

31 Astronomisches Institut der Ruhr-Universität Bochum

32 AIP - Leibniz-Institut für Astrophysik Potsdam

33 Department of Physical Sciences, University of Oulu

34 Curtin University [Perth]

35 Radboud university [Nijmegen]

36 University of Groningen [Groningen]

37 CRAL - Centre de Recherche Astrophysique de Lyon

38 ATNF - Australia Telescope National Facility

39 ING - Institute of Farm Animal Genetics

40 SKA South Africa

41 AIP - Astrophysikalisches Institut Potsdam

42 Department of Physics [Dunedin]

43 Princeton University

44 Edinburgh Research Station

45 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique

46 Department of Astrophysics [Nijmegen]

47 Anton Pannekoek Institute for Astronomy

48 AlfA - Argelander-Institut für Astronomie

Abstract : Context. LOFAR offers the unique capability of observing pulsars across the 10−240 MHz frequency range with a fractional bandwidth of roughly 50%. This spectral range is well suited for studying the frequency evolution of pulse profile morphology caused by both intrinsic and extrinsic effects such as changing emission altitude in the pulsar magnetosphere or scatter broadening by the interstellar medium, respectively. Aims. The magnitude of most of these effects increases rapidly towards low frequencies. LOFAR can thus address a number of open questions about the nature of radio pulsar emission and its propagation through the interstellar medium. Methods. We present the average pulse profiles of 100 pulsars observed in the two LOFAR frequency bands: high band (120–167 MHz, 100 profiles) and low band (15–62 MHz, 26 profiles). We compare them with Westerbork Synthesis Radio Telescope (WSRT) and Lovell Telescope observations at higher frequencies (350 and 1400 MHz) to study the profile evolution. The profiles were aligned in absolute phase by folding with a new set of timing solutions from the Lovell Telescope, which we present along with precise dispersion measures obtained with LOFAR. Results. We find that the profile evolution with decreasing radio frequency does not follow a specific trend; depending on the geometry of the pulsar, new components can enter into or be hidden from view. Nonetheless, in general our observations confirm the widening of pulsar profiles at low frequencies, as expected from radius-to-frequency mapping or birefringence theories.

Keywords : stars: neutron pulsars: general

Document type :

Journal articles

Domain :

Sciences of the Universe [physics]

Complete list of metadata

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Submitted on : Tuesday, February 14, 2017 - 10:56:24 AM
Last modification on : Saturday, September 24, 2022 - 12:02:05 PM
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