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The GLEAM 4-Jy (G4Jy) Sample is a thorough compilation of the ‘brightest’ radio sources in the southern sky (Declination 
$ \lt 30^{\circ}$), as measured at 151 MHz (
$S_{\mathrm{151\,MHz}} \gt 4.0$ Jy) with the Murchison Widefield Array (MWA), through the GaLactic and Extragalactic All-sky MWA (GLEAM) Survey. In addition to flux-density measurements, the G4Jy catalogue (https://github.com/svw26/G4Jy.) provides host-galaxy identifications (through careful visual-inspection) and four sets of spectral indices. Despite their brightness in the radio, many of these sources are poorly studied, with the vast majority lacking a spectroscopic redshift in published work. This is crucial for studying the intrinsic properties of the sources, and so we conduct a multi-semester observing campaign on the Southern African Large Telescope (SALT), with optical spectroscopy enabling us to provide new redshifts to the astronomical community. Initial results show that not all of the host galaxies exhibit emission-line spectra in the optical (
$\sim$4 500–7 500Å), which illustrates the importance of radio-frequency selection (rather than optical selection) for creating an unbiased sample of active galactic nuclei. By combining SALT redshifts with those from the 6-degree Field Galaxy Survey (6dFGS) and the Sloan Digital Sky Survey (SDSS), we calculate radio luminosities and linear sizes for 299 G4Jy sources (which includes one newly-discovered giant radio-galaxy, G4Jy 604). Furthermore, with the highest redshift acquired (so far) being 
$z \sim 2.2$ from SDSS, we look forward to evolution studies of this complete sample, as well as breaking degeneracies in radio properties with respect to, for example, the galaxy environment.
Before a binary system enters into a common envelope (CE) phase, accretion from the primary star onto the companion star through Roche Lobe overflow (RLOF) will lead to the formation of an accretion disk, which may generate jets. Accretion before and during the CE may alter the outcome of the interaction. Previous studies have considered different aspects of this physical mechanism. Here we study the properties of an accretion disk formed via 3D hydrodynamic simulations of the RLOF mass transfer between a 7 M
$_{\odot}$, red supergiant star and a 1.4 M
$_{\odot}$, neutron star companion. We simulate only the volume around the companion for improved resolution. We use a 1D implicit mesa simulation of the evolution of the system during 30 000 yr between the on-set of the RLOF and the CE to guide the binary parameters and the mass-transfer rate, while we simulate only 21 yr of the last part of the RLOF in 3D using an ideal gas quasi-isothermal equation of state. We expect that a pre-CE disk under these parameters will have a mass of 
$\sim 5\times 10^{-3}$ M
$_{\odot}$ and a radius of 
$\sim40\ R_\odot$ with a scale height of 
$\sim 5\ R$
$_{\odot}$. The temperature profile of the disk is shallower than that predicted by the formalism of Shakura and Sunyaev, but more reasonable cooling physics would need to be included. We stress test these results with respect to a number of physical and numerical parameters, as well as simulation choices, and we expect them to be reasonable within a factor of a few for the mass and 15% for the radius. We also contextualise our results within those presented in the literature, in particular with respect to the dimensionality of simulations and the adiabatic index. We discuss the measured accretion rate in the context of the Shakura and Sunyaev formalism and debate the viscous mechanisms at play, finishing with a list of prospects for future work.
