VLBA Snapshot Imaging Survey of Scintillating Sources

Author/Creator ORCID

Date

2004-10-01

Department

Program

Citation of Original Publication

Roopesh Ojha, Alan L. Fey, James E. J. Lovell, David L. Jauncey, and Kenneth J. Johnston, VLBA Snapshot Imaging Survey of Scintillating Sources, The Astronomical Journal, Volume 128, Number 4, https://doi.org/10.1086%2F423916

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Public Domain Mark 1.0
This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law

Subjects

Abstract

We present 8.4 GHz Very Long Baseline Array (VLBA) observations of 75 extragalactic radio sources drawn from the scintillating sources discovered in the Microarcsecond Scintillation-induced Variability survey. This survey clearly showed that the fraction of scintillating sources and the amplitude of their variability increases strongly with decreasing flux density, raising the possibility that scintillating sources may be systematically extremely core dominated. The observations presented here were designed to investigate this hypothesis. The results indeed show that most of the scintillating sources we observed with the VLBA have an extremely compact, core-dominated morphology, which has important implications for interpretations of the scintillation seen in these sources. In addition, these sources are potential candidates for inclusion in the International Celestial Reference Frame.