All-sky Wide Infrared Survey Explorer (AllWISE) DR3. For this poster, we focus on Abell 2485 cluster field, with the following details: As a final step, we manually checked for candidates against the NASA/IPAC Extragalactic Database to look for any redshif t information , o r whethe r a sourc e exist s i n othe r optical/ IR catalogues. Our final HzRG candidate list contains a total of 331 sources: 229 USS sources and 102 potential HzRG candidates with n o spectral index information. 5σ Searching for high-redshift radio galaxies with the MeerKAT Galaxy Cluster Legacy Survey 1, 2 1, * Centre for Radio Astronomy Techniques and Technologies, Department of Physics and Electronics, Rhodes University, Makhanda, South Africa South African Radio Astronomy Observatory, Fir Street, Observatory, South Africa cossav25@gmail.com 1 2 Vasco Cossa , Kenda Knowles * Abstract MGCLS data Exploring the high redshift Universe is critical to our understanding of cosmological and astrophysical processes. This poster presents a search for high-redshift radio galaxies (HzRG) using 1.28 GHz da ta fr om t he MeerK AT Gala xy Clust er Lega cy Surv ey (MGCL S). Thro ugh rigor ous select ion criter ia, we identif ied 331 HzRG candid ate s in the A bell 2485 fi eld. This s hows that the MGCLS d ata's sensit ivit y and band width ma ke it a s trong to ol for discovering potential HzRG candidates in the Southern sky. The MGCLS DR1 products provide a compact source catalogue for 115 fields. Utilizing Knowles e t al . (2021) , w e filte r fo r field s wit h goo d dynam ic range and astrometry corrections. Subsequently, we narrow down to 39 fields with complete coverag e in both Dark Energy Camera Legacy Survey (DECaLS) DR10 and Methods and results for Abell 2485 7170 RMS Noise Step 1: Signal-to-noise and angular size requirements Abell 2485 field poses few bright-source artifacts, however, the image noise does vary across the field due to the primary bea m correction, with the local RMS noise increasing away from t he ima ge centr e. Rath er th an implementi ng a fix ed fl ux dens ity cut, we apply a signal-to-noise ratio (SNR) restriction using the fi tted flux den sity ve rsus its associ ated uncertai nt y. We simultaneously apply an angular size restriction. Step 2: Multi-wavelength cross-matching This study highlights the potential of MGCLS DR1 data for identifying HzRG candidates. Among the 115 fields, 39 offer a goo d dynami c rang e an d comprehensiv e coverag e i n DECa LS and AllWISE. Expanding the study to these fields could yield more candidates for spectroscopic follow-up. Likelihood ratio method We use the likelihood ratio (LR) method, introduced by Sutherland and Saunders (1992), to cross-match our radi o catalo g wit h multi-wavelengt h catalogues , an d t o exclu de optical and infrared counterparts as HzRGs candidates. The LR is defined as the ratio of the probability that an optical source is the true counterpart, to the probability that the sam e source is a spurious alignment, i.e., q(m) is the expected magnitude distribution for the true counterparts; f(r) is the probability distribution function of the positional uncertainties in the involved catalogues; n(m) is the surface density of the unrelated background objects with magnitude m. Step 3: Ultra-Steep Spectrum (USS) selection We are currently exploring the now-established correlation between galaxy redshift and radio spectral steepnes s (Röttgering et al., 1994). Step 4: Manual cross-checking with NED and Vizier Conclusion References 3512 3046 SNR Angular size smaj ≤ 10'' Fig 1. MGCLS Abell 2485 field with DECaLS and AllWISE coverage Fig 2. Angular separations between the positions of radio sources in the Abell 2485 and their DECaLS counterparts. In each panel, the red line shows the normalise d Gaussian distribution Fig 3. MGCLS Abell 2485–DECaLS cross-match results. The vertical dashed line indicates the optimal threshold LR > 0.1 Fig 4. Angular separations between the positions of ra