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Examples of Extreme Intraday Variability

Published online by Cambridge University Press:  12 April 2016

Lucyna Kedziora-Chudczer ,
David L. Jauncey ,
Mark A. Wieringa ,
Anastasios K. Tzioumis  and
Hayley E. Bignall
Lucyna Kedziora-Chudczer
Affiliation:
Anglo-Australian Observatory Australia Telescope National Facility, Australia. E-mail: {lkedzior;djauncey;mwiering;atziouml}@atnf.csiro.au
David L. Jauncey
Affiliation:
Australia Telescope National Facility, Australia. E-mail: {lkedzior;djauncey;mwiering;atziouml}@atnf.csiro.au
Mark A. Wieringa
Affiliation:
Australia Telescope National Facility, Australia. E-mail: {lkedzior;djauncey;mwiering;atziouml}@atnf.csiro.au
Anastasios K. Tzioumis
Affiliation:
Australia Telescope National Facility, Australia. E-mail: {lkedzior;djauncey;mwiering;atziouml}@atnf.csiro.au
Hayley E. Bignall
Affiliation:
University of Adelaide, Australia. E-mail: [email protected]

Abstract

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We present results of the ATCA IDV Survey of southern extragalactic radio sources. We discuss briefly the properties of the 22 new intraday variable sources discovered in the Survey. The follow-up observations of a few extreme examples of strong intraday variability are presented. We find that the characteristics of the total flux density fluctuations at different wavelengths are consistent with intersteller scintillations (ISS) of the microarcsecondsize soorten components. However, the scintillating components of a few extreme IDVs are characterized by the brightness temperatures far exceeding the TB = 1012 K limit. The relativistic beaming invoked in such sources would require Doppler factors up to as high as δ ~ 103.

Type
Chapter Three Intra-Day Variability, Gravitational Lensing and Polarization
Information
International Astronomical Union Colloquium , Volume 182: Sources and Scintillations: Refraction and Scattering in Radio Astronomy , 2001 , pp. 113 - 117
Copyright
Copyright © Kluwer 2001

References

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