2024/07/04 by D. Y. Klutse, Matt Hilton, Klutse, D. Y. +11 · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2407.03667
We present the first detailed radio study of the galaxy cluster XMMXCS J2215.9-1738 at z = 1.46 using MeerKAT L-band (1.3 GHz) observations. We combine our radio observation with archival optical and infrared data to investigate the star formation and AGN population within R200 (R = 0.8 Mpc) of the cluster centre. Using three selection criteria; the radio luminosity, the far-infrared radio ratio (q_\rmIR) and the mid-infrared colour, we distinguish galaxies with radio emission predominantly powered by star formation from that powered by AGNs. We selected 24 cluster members within R_\rm200 in the MeerKAT image based on either their photometric or spectroscopic redshift. We classified 12/24 (50%) as galaxies whose radio emission is dominated by star-formation activity, 6/24 (25%) as intermediate star-forming galaxies and 6/24 (25%) as AGN-dominated galaxies. Using the radio continuum luminosities of the star-forming cluster galaxies, we estimated an integrated star formation rate (SFR) value of 1700 ± 330 M\odotyr-1 within R200. We derived a mass-normalized integrated SFR value of (570 ± 110) × 10-14 yr-1. This supports previous observational and theoretical studies that indicated a rapid increase in star formation activity within the core of high-redshift clusters. We also show that the high AGN fraction within the cluster core is consistent with previous cluster observations at z > 1.5.