Hostname: page-component-76fb5796d-dfsvx Total loading time: 0 Render date: 2024-04-26T13:53:24.717Z Has data issue: false hasContentIssue false

Broadband observations of pulsar profiles and frequency dependent DMs

Published online by Cambridge University Press:  04 June 2018

Isabella Rammala
Affiliation:
Department of Physics and Electronics, Rhodes University, Drosty Road, Grahamstown 6139, South Africa
Aris Karastergiou
Affiliation:
Department of Physics and Electronics, Rhodes University, Drosty Road, Grahamstown 6139, South Africa Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK Physics Department, University of the Western Cape, Cape Town 7535, South Africa
Griffin Foster
Affiliation:
Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The aim of our project is to search for ways to best extract information on pulsar profiles and the interstellar medium (ISM), using the wide frequency bands that are typical of radio telescopes today. Pulsar profiles typically show a strong dependence on frequency. This depends both on the intrinsic radio emission mechanism, and the interaction of the radio waves with the ISM that lies between the pulsars and our detectors on Earth, due mostly to the effects of dispersion and scattering. In this work, we make use of radio pulsar beam models from the existing literature, to generate simulated pulse profiles, observed across various bands (centre frequencies and bandwidths), for each beam model. For all the chosen geometric parameters of the pulsar beam, observed in any frequency band, the simulated profiles manifest a relative shift in phase in their observed components, as a result of the intrinsic profile evolution. This relative shift in phase could be interpreted as an additional component to the ISM induced dispersion measure (DM). This additional DM component due to profile evolution is frequency dependent. We discuss the systematics introduced to pulsar data due to this effect.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2018 

References

Backer, D. C., 1976, ApJ, 209, 895CrossRefGoogle Scholar
Karastergiou, A., & Johnston, S., 2007, MNRAS, 380, 1678Google Scholar