Research Note

Pulsars with gigahertz-peaked spectra

¹ Kepler Institute of Astronomy, University of Zielona Góra, Lubuska 2, 65-265 Zielona Góra, Poland
e-mail: jkijak@astro.ia.uz.zgora.pl
² National Centre for Radio Astrophysics, TIFR, Pune University Campus, Pune, India
³ Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany

Received: 17 February 2010
Accepted: 2 April 2011

Abstract

Aims. We investigate a high frequency turn-over effect in radio spectra for pulsars with positive or flat spectral index.

Methods. Using GMRT and Effelsberg observatory, we estimated the flux density to reconstruct pulsar spectra.

Results. We find objects that have a maximum flux in their spectrum above 1 GHz, whose emitted energy decreases below 1 GHz and whose spectral indices are positive at lower frequencies. Some pulsars with a turn-over in their spectrum at high frequencies are found to exist in very interesting environments. We call these objects gigahertz-peaked spectra pulsars.