Examples of Extreme Intraday Variability
- 109 Downloads
We present results of the ATCA IDV Survey of southern extragalactic radio sources. Wediscuss briefly the properties of the 22 new intraday variable sources discovered in the Survey. Thefollow-up observations of a few extreme examples of strong intraday variability are presented. Wefind that the characteristics of the total flux density fluctuations at different wavelengths are consistentwith intersteller scintillations (ISS) of the microarcsecondsize soorten components. However, thescintillating components of a few extreme IDV s are characterized by the brightness temperatures farexceeding the T B = 1012 K limit. The relativistic beaming invoked in such sources would requireDoppler factors up to as high as ´ ~ 103.
KeywordsBrightness Temperature Radio Source Coherent Emission Doppler Factor Inverted Spectrum
Unable to display preview. Download preview PDF.
- Duncan, R.A., White, G.L., Wark, R., Reynolds, J.E., Jauncey, D.L., Norris, R.P. and Taaffe L.: 1993, Proc. ASA 10, 310P.Google Scholar
- Kedziora-Chudczer, L.L., Jauncey, D.L., Wieringa, M.H., Reynolds, J.E. and Tzioumis, A.K.: 2000, MNRAS, submitted.Google Scholar
- Macquart, J.-P., Kedziora-Chudczer, L., Jauncey, D.L. and Rayner, D.P.: 2000, to appear in ApJ 538.Google Scholar
- Rickett, B.J., Quirrenbach, A., Wegner, R., Krichbaum, T.P. and Witzel, A.: 1995, A&A 293, 479P.Google Scholar
- Wagner, S.J. and Witzel, A.: 1995, ARA&A 33, 163P.Google Scholar
- Witzel, A., Heeschen, D.S., Schalinski, C.J. and Krichbaum, T.P.: 1986, Mitt. Astron. Ges. 65, 239P.Google Scholar