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BL LAC OBJECT PKS B1144−379: An extreme scintillator


Turner, RJ and Ellingsen, SP and Shabala, SS and Blanchard, J and Lovell, JEJ and McCallum, JN and Cimo, G, BL LAC OBJECT PKS B1144−379: An extreme scintillator, The Astrophysical Journal Letters, 754, (2) Article L19. ISSN 2041-8205 (2012) [Refereed Article]

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Copyright 2012 The American Astronomical Society

DOI: doi:10.1088/2041-8205/754/2/L19


Rapid variability in the radio flux density of the BL Lac object PKS B1144–379 has been observed at four frequencies, ranging from 1.5 to 15 GHz, with the Very Large Array and the University of Tasmania's Ceduna antenna. Intrinsic and line-of-sight effects were examined as possible causes of this variability, with interstellar scintillation best explaining the frequency dependence of the variability timescales and modulation indices. This scintillation is consistent with a compact source 20-40 μas or 0.15-0.3 pc in size. The inferred brightness temperature for PKS B1144–379 (assuming that the observed variations are due to scintillation) is 6.2 × 1012 K at 4.9 GHz, with approximately 10% of the total flux in the scintillating component. We show that scintillation surveys aimed at identifying variability timescales of days to weeks are an effective way to identify the active galactic nuclei with the highest brightness temperatures.

Item Details

Item Type:Refereed Article
Keywords:galaxies: active; ISM: structure; scattering
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Cosmology and extragalactic astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:Turner, RJ (Dr Ross Turner)
UTAS Author:Ellingsen, SP (Professor Simon Ellingsen)
UTAS Author:Shabala, SS (Associate Professor Stas Shabala)
UTAS Author:Blanchard, J (Mr Jay Blanchard)
UTAS Author:Lovell, JEJ (Dr Jim Lovell)
UTAS Author:McCallum, JN (Dr Jamie McCallum)
ID Code:78791
Year Published:2012
Web of Science® Times Cited:4
Deposited By:Mathematics and Physics
Deposited On:2012-07-26
Last Modified:2017-11-01

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