Tracing Large-scale Structure with the MeerKLASS On-the-Fly Survey: Angular Clustering of Radio Sources at 816 MHz

We present the first measurement of the angular two-point correlation function w(theta) of radio sources from the MeerKAT Large Area Synoptic Survey (MeerKLASS) UHF on-the-fly (OTF) continuum Data Release 1. DR1 provides interferometric Stokes- I imaging at a reference frequency of 816,MHz over about 800 deg squared within the DESI footprint. We detect a positive clustering signal over 0.02 theta 10. The measurement is stable to reasonable variations of the depth mask and flux threshold on intermediate and large scales. Modelling the intermediate-scale signal (0.112 theta 1.36) with a fixed-slope power law (gamma=1.8) yields A(1)=(1.434 plus or minus0.475) times10-3, corresponding to 10A=-2.843+0.124-0.175. We infer an effective large-scale bias by fitting CDM projected-matter templates w DM(theta) computed with CAMB and Limber projection, including an integral-constraint correction evaluated from random--random weights. Using two bracketing T-RECS redshift-distribution priors, we obtain b eff=1.998 plus or minus0.350 (AGN prior) and b eff=1.530 plus or minus0.265 (TOTAL prior), demonstrating that the dominant modelling uncertainty arises from N(z). As a derived summary we Limber-invert the power-law amplitude to obtain r 0=6.18 plus or minus1.13 and 5.59 plus or minus1.02 h-1 Mpc for the AGN and TOTAL priors, respectively. These results establish MeerKLASS UHF DR1 as a new wide-area, intermediate-frequency dataset for radio-continuum clustering. As MeerKLASS expands and overlapping optical/IR spectroscopy provides improved redshift calibration, future releases will enable population-split clustering and bias evolution measurements with substantially reduced modelling uncertainty.