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Multi-frequency scatter-broadening evolution of pulsars

Published online by Cambridge University Press:  04 June 2018

M. A. Krishnakumar
Affiliation:
Radio Astronomy Centre, NCRA–TIFR, Ooty - 643 001, India National Cente for Radio Astrophysics, TIFR, Pune - 411 007 Bharathiar University, Coimbatore - 641 046 email: [email protected]
Bhal Chandra Joshi
Affiliation:
National Cente for Radio Astrophysics, TIFR, Pune - 411 007
P. K. Manoharan
Affiliation:
Radio Astronomy Centre, NCRA–TIFR, Ooty - 643 001, India National Cente for Radio Astrophysics, TIFR, Pune - 411 007
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Abstract

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In this paper, we present our study on multi-frequency scatter-broadening observations of a large sample of pulsars, made using the Ooty Radio Telescope (ORT) and the Giant Metrewave Radio Telescope (GMRT). For each pulsar, the scatter-broadening time scales (τsc) have been estimated at different observing frequencies and the dependence of τsc with the observing frequency, i.e., the frequency scaling index (α) has been obtained. We report estimates of α for a set of 39 pulsars, of which 31 are completely new and provide the first-time measurement on about 50% of the sample. This enhanced sample suggests that almost 65% of the pulsars have an α much lower than the conventional value of 4.4 for a Kolmogorov type turbulence spectrum, and a considerably large scattering strength. An increase in scattering strength is observed with the distance to the pulsar in the Galaxy.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2018 

References

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