Observations of 44 extragalactic radio sources with the VLBA at 92cm: A List of Potential Calibrators and Targets for LOFAR and RadioAstron

TL;DR

This study analyzed archival VLBA 92cm data of 44 extragalactic radio sources to identify suitable calibrators and targets for LOFAR and RadioAstron, providing a valuable resource for future radio astronomy observations.

Contribution

It presents the first systematic analysis of VLBA 92cm data for these sources, identifying potential calibrators and targets for LOFAR and RadioAstron.

Findings

34 sources detected on at least one VLBA baseline

30 sources successfully imaged with sufficient data

13 sources detected on the longest VLBA baselines

Abstract

Aims. We have analysed VLBA 92cm archive data of 44 extragalactic sources in order to identify early targets and potential calibrator sources for the LOFAR radio telescope and the RadioAstron space VLBI mission. Some of these sources will also be suitable as in-beam calibrators, permitting deep, wide-field studies of other faint sources in the same field of view. Methods. All publicly available VLBA 92cm data observed between 1 January 2003 to December 31 2006 have been analysed via an automatic pipeline, implemented within AIPS. The vast majority of the data are unpublished. Results. The sample consists of 44 sources, 34 of which have been detected on at least one VLBA baseline. 30 sources have sufficient data to be successfully imaged. Most of the sources are compact, with a few showing extended structures. Of the 30 sources imaged, 13 are detected on the longest VLBA baselines (approx. 9 Mega wavelengths), while all were detected on baselines greater than 2 Mega wavelengths (the maximum baseline of LOFAR including the current international baselines).