Hintze Centre for Astrophysical Surveys

Abstract:

Accretion and relativistic jet formation in black holes occur across a wide range of their masses, revealing qualitative and quantitative similarities that connect the entire population of black holes. In March 2026, researchers from all areas across the black hole mass spectrum met in Oxford to educate, explore and forge new research directions.

Abstract:

Abstract We report the discovery and characterisation of MKT J032848.4–271904.6, a new radio transient identified in the LADUMA field using SARAO Science Data Processor SDP UHF-band images from approximately one year of MeerKAT observations. Using the Transient Pipeline TraP and advanced filtering techniques, we identified a number of candidate variable radio sources in the field. All but one show variability consistent with refractive interstellar scintillation, leaving MKT J032848.4–271904.6 as the sole source exhibiting intrinsic variability. In addition, MKT J032848.4–271904.6 shows intrinsic variability at 0.816 GHz, with 13 radio detections across 41 epochs and a peak flux density of 1.041 ± 0.043 mJy. We associate this emission with a low-mass M-dwarf star LP 888–63, located 23 pc from the Sun and identified as a companion to the white dwarf binary system LAWD 14 WD 0326–273. LP 888–63 displays active flaring behaviour across the electromagnetic spectrum including multi-band optical data from MeerLICHT. TESS photometry reveals a periodic modulation in the blended light curve of 5.780 ± 0.507 days, consistent with rotational variability of a mid-M dwarf. Archival ESO spectra reveal Hα emission, confirming magnetic activity. These findings highlight the capability of MeerKAT’s SDP imaging and facilities like MeerLICHT for real-time detection and characterisation of stellar transients.

Abstract:

Abstract Radio continuum surveys provide samples of active galactic nuclei (AGN) and star forming galaxies (SFGs) to high redshifts, free of biases due to dust obscuration. However, radio detected sources require multi-wavelength counterparts to understand their intrinsic properties (e.g. redshift, stellar mass) and to study the evolution of star formation and AGN activity. In this work we present host galaxy counterparts for the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) survey continuum Data Release 1 in regions with the best ancillary data (totalling 7.5 sq. deg). We combine statistical cross-matching and visual inspection to identify Ks-band selected host galaxies, and additionally combine multiple radio components into single physical objects, where needed. This results in a combined radio catalogue of ~66 000 sources, with host counterparts and redshifts identified for ~95 per cent of sources in the COSMOS field, ~91 per cent in XMM-LSS and ~90 per cent in CDFS-DEEP. This includes a significant fraction of sources with spectroscopic redshifts within the COSMOS field (~50 per cent), with ~30 and ~20 per cent in the XMM-LSS and CDFS-DEEP fields respectively. Using the cross-matched catalogue, we make an initial identification of radio-excess and star forming galaxies based on comparisons of the radio luminosities to host star formation rates. Using this split as a proxy for radio loud AGN or SFGs, we present expectations for the redshift distributions of these sources, finding broad agreement with those from deep radio luminosity functions and simulated catalogues.