The HERA telescope, an array of 350 antennas situated next to MeerKAT in the Northern Cape province of South Africa, is being built by a team of local artisans from the town of Carnarvon. It has now released its first set of observations to the world, giving a glimpse of what the Universe looked like about …
We investigate the 1/f noise of the Five-hundred-meter Aperture Spherical Telescope (FAST) receiver system using drift-scan data from an intensity mapping pilot survey. All the 19 beams have 1/f fluctuations with similar structures. Both the temporal and the 2D power spectrum densities are estimated. The correlations directly seen in the time series data at low …
We present a novel 2D flux density model for observed HI emission lines combined with a Bayesian stacking technique to measure the baryonic Tully-Fisher relation below the nominal detection threshold. We simulate a galaxy catalogue, which includes HI lines described either with Gaussian or busy function profiles, and HI data cubes with a range of …
Traditional large-scale models of reionization usually employ simple deterministic relations between halo mass and luminosity to predict how reionization proceeds. We here examine the impact on modelling reionization of using more detailed models for the ionizing sources as identified within the 100 Mpc/h cosmological hydrodynamic simulation Simba, coupled with post-processed radiative transfer. Comparing with simple (one-to-one) models, the …
Using a sample of 67 galaxies from the MIGHTEE Survey Early Science data we study the HI-based baryonic Tully-Fisher relation (bTFr), covering a period of ∼one billion years (0≤z≤0.081). We consider the bTFr based on two different rotational velocity measures: the width of the global HI profile and Vout, measured as the outermost rotational velocity from the …
We use a generic formalism designed to search for relations in high-dimensional spaces to determine if the total mass of a subhalo can be predicted from other internal properties such as velocity dispersion, radius, or star-formation rate. We train neural networks using data from the Cosmology and Astrophysics with MachinE Learning Simulations (CAMELS) project and …
Measuring the total neutrino mass is one of the most exciting opportunities available with next-generation cosmological data sets. We study the possibility of detecting the total neutrino mass using large-scale clustering in 21cm intensity mapping and photometric galaxy surveys, together with CMB information. We include the scale-dependent halo bias contribution due to the presence of …
The award was announced during UWC’s Annual Research Recognition Awards and presented by the DVC Research and Innovation, Prof. Jozé Frantz. Mogamad-Junaid competed his MSc Summa Cum Laude within 2 years of enrolling. His hope is to go on and pursue a career as a cosmologist, studying the history and evolution of the universe, while …
On the evening of August 24, a bright object traveling fast in the upper atmosphere had thousands of people mesmerised. It was spotted by many in the Gauteng province of South Africa but was visible further North into Limpopo and Zimbabwe. At first we didn’t know what it was. ☄️BREAKING: SA Astronomical Observatory confirms large #meteor/fireball …
Peaking at 3.7 mag on 2020 July 11, YZ Ret was the second-brightest nova of the decade. The nova’s moderate proximity (2.7 kpc from Gaia) provided an opportunity to explore its multi-wavelength properties in great detail. Here we report on YZ Ret as part of a long-term project to identify the physical mechanisms responsible for …
