LBA observations for project V606 semester 2021APRS

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Widefield Interplanetary scintillation studies with the Murchison Widefield Array has identified objects that are compact at 0.3 arcsecond angular scales and have a steep-spectrum. Such objects are very rare in the Active Galactic Nuclie population and are excellent pulsar candidates. This technique involving angular size as a discriminator reduces the number of objects pulsar candidates by a factor of ~45 compared to those selected from continuum source catalogues using spectra only. At Very Long Baseline Interferometry (VLBI) scales, pulsars remain unresolved. However, if sources have structures at VLBI scales, then such objects are interesting as compact steep-spectrum (CSS) objects with morphologies similar to extended radio galaxies and linear size >1 kpc but <20 kpc. Our IPS studies find that our compact and steep-spectrum objects consist of sources that are unresolved as well as resolved at IPS scales while we expect CSS sources to be resolved. We aim to investigate this population of steep-spectrum and compact sources by studying their morphology at VLBI scales. If the objects are unresolved at VLBI scales, they become compelling pulsar candidates to be followed up with Parkes for pulse searches. If they are resolved at VLBI scales, we want to investigate if we can consolidate them as a single extragalactic CSS source population using morphology. Additionally, we will use these observations as a first step to obtain high quality astrometry so that the proper motion and parallax of pulsar candidates may be measured over multiple epochs to constrain their distances.