Low-frequency variability and the galactic distribution of electron-density fluctuation

Ghosh, T and Rao, AP (1992) Low-frequency variability and the galactic distribution of electron-density fluctuation. In: Astronomy & Astrophysics, 264 (1). pp. 203-216.

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Abstract

A sample of 96 compact flat-spectrum extragalactic sources, spread evenly over all galactic latitudes, has been studied at 327 MHz for variability over a time interval of about 15 yr. The variability shows a dependence on galactic latitude being less both at low and high latitudes and peaking around absolute value of b approximately 15-degrees. The latitude dependence is surprisingly similar in both the galactic centre and anticentre directions. Assuming various single and multi-component distributions for the ionized, irregular interstellar plasma, we have tried to generate the observed dependence using a semi-qualitative treatment of refractive interstellar scintillations. We find that it is difficult to fit our data with any single or double component cylindrical distribution. Our data suggests that the observed variability could be influenced by the spiral structure of our Galaxy.

Item Type:	Journal Article
Publication:	Astronomy & Astrophysics
Publisher:	EDP Sciences
Additional Information:	Copyright of this article belongs to EDP Sciences.
Department/Centre:	Division of Physical & Mathematical Sciences > Joint Astronomy Programme
Date Deposited:	05 May 2011 06:34
Last Modified:	05 May 2011 06:34
URI:	http://eprints.iisc.ac.in/id/eprint/37197

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