Dr Ann Burgess (Sydney University)

The Molonglo Southern 4 Jy Sample - Dr Ann Burgess Colloquium

ATNF Marsfield Lecture Theatre

Abstract

A complete sample of 228 strong extragalactic radio sources has been
selected at declinations south of -30 degrees, and will be a valuable
resource for detailed studies of radio galaxies and quasars. The
Molonglo Southern 4 Jy sample (MS4) was designed to be a southern
complement to the well studied northern 3C sample. MS4 was defined at
408 MHz using the Molonglo Reference Catalogue as the main finding
survey. Sources were imaged at 843 MHz with the Molonglo Observatory
Synthesis Telescope. Radio spectra were used to define a strong-source
subset (called SMS4) at 178 MHz, with a flux density limit of 10.9 Jy,
providing a close equivalent to the revised northern sample, 3CRR. The
SMS4 and 3CRR samples show a reassuring similarity in source density
and median flux density. The 133 MS4 sources with angular size <35
arcsec were imaged at 5 GHz at 2-4 arcsec resolution with the Australia
Telescope Compact Array. More than 90% of the MS4 sample was reliably
optically identified, either with the UK Schmidt Southern Sky Survey or
with R-band CCD images from the Anglo-Australian Telescope. Linear
sizes of MS4 galaxies and quasars were found to be consistent with
galaxy-quasar unification models of orientation and evolution. This
colloquium will discuss the steps taken to ensure the sample's
completeness, the observational data, and prospects for further studies.