The transformation and evolution of a galaxy is strongly influenced by interactions with its environment. Neutral hydrogen (HI) is an excellent way to trace these interactions. Here, we present HI observations of the spiral galaxy NGC~895, which was previously thought to be isolated. High-sensitivity HI observations from the MeerKAT large survey project MIGHTEE reveal possible …
Context: To study the effects of environment on galaxies we use HI observations of galaxies in and around the cluster A2626. The cluster can effectively be divided in three different environments: the cluster itself, a group environment in the periphery of the cluster (we call it the Swarm) and substructure in the cluster itself. We …
We study the nature of the faint radio source population detected in the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Early Science data in the COSMOS field, focusing on the properties of the radio-loud active galactic nuclei (AGN). Using the extensive multi-wavelength data available in the field, we are able to classify 88 per cent …
The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) aims to improve constraints on the dark energy equation of state through measurements of large-scale structure at high redshift (0.8<z<2.5), while serving as a state-of-the-art fast radio burst detector. Bright galactic foregrounds contaminate the 400–800~MHz HIRAX frequency band, so meeting the science goals will require precise instrument …
We present measurements of the rest-frame ultraviolet luminosity function (UV LF) at redshifts z=3, z=4 and z=5, using 96894, 38655 and 7571 sources respectively to map the transition between AGN and galaxy-dominated ultraviolet emission shortly after the epoch of reionization. Sources are selected using a comprehensive photometric redshift approach, using 10\ds\, of deep extragalactic legacy fields covered by both HSC …
We study the nature of the low-redshift CGM in the Simba cosmological simulations as traced by ultraviolet absorption lines around galaxies in bins of stellar mass (M⋆>1010M⊙) for star-forming, green valley and quenched galaxies at impact parameters r⊥≤1.25r200. We generate synthetic spectra for HI, MgII, CII, SiIII, CIV, and OVI, fit Voigt profiles to obtain line …
We report the emergence of a new HI 21-cm absorption at z_abs = 1.172635 in the damped Lyman-alpha absorber (DLA) towards the gamma-ray blazar PKS 2355-106 (z_em~1.639) using science verification observations (June 2020) from the MeerKAT Absorption Line Survey (MALS). Since 2006, this DLA is known to show a narrow HI 21-cm absorption at z_abs …
We investigate how much can be learnt about four types of primordial non-Gaussianity (PNG) from small-scale measurements of the halo field. Using the \textsc{quijote-png} simulations, we quantify the information content accessible with measurements of the halo power spectrum monopole and quadrupole, the matter power spectrum, the halo-matter cross spectrum and the halo bispectrum monopole. This …
We provide perturbation theory predictions for the HI intensity mapping power spectrum multipoles using the Effective Field Theory of Large Scale Structure (EFTofLSS), which should allow us to constrain cosmological parameters exploiting mildly nonlinear scales. Assuming survey specifications typical of proposed interferometric HI intensity mapping experiments like CHORD and PUMA, and realistic ranges of validity …
In anticipation of the new era of high-redshift exploration marked by the commissioning of the James Webb Space Telescope (JWST), we present two sets of galaxy catalogues that are designed to aid the planning and interpretation of observing programs. We provide a set of 40 wide-field lightcones with footprints spanning approximately ~ 1,000 sq. arcmin, …
