Digest
Rodríguez et al. report a 3.0 GHz detection of the z=0.4332 local little red dot analog J204837.26−002437.2 (J2048), linking JWST-era LRD phenomenology to a nearby compact-red-continuum system with a broad-line AGN and intense starburst. At 3.0±0.2 mJy, J2048 is roughly two orders of magnitude more radio luminous than the two previously detected LLRD analogs, with a relatively flat α=−0.39±0.04 spectrum consistent with moderately optically thick synchrotron emission and a radio luminosity of 1.2×10^41 erg s⁻¹. Its unresolved radio core, possible southeast extension, and luminosity near the low end of radio-loud ellipticals and quasars make it a promising laboratory for testing radio feedback in LRD-like nuclei; the authors argue that the black-hole radio output may nevertheless be suppressed by about an order of magnitude. A similarly luminous z>4 LRD should be reachable with moderately deep VLA observations, offering a concrete route to test whether distant LRDs are intrinsically radio weak or merely hard to detect.
Key figures to inspect
- Figure 1. The stacked 3 GHz VLASS map establishes the central observational result: J2048 is radio-bright and largely unresolved at its Gaia optical position. The marginal southeast protuberance is especially important because it may trace a kpc-scale jet or a second component in a merging ULIRG-like system, directly connecting the detection to competing AGN-feedback and starburst interpretations.
- Figure 2. The multi-survey radio spectrum provides the paper’s key physical diagnostic, showing the fitted spectral index α=−0.39±0.04. Its moderately flat, optically thick synchrotron-like slope underpins the argument that J2048 is not simply a faint star-formation radio counterpart but a useful analog for assessing suppressed or obscured black-hole-linked radio emission in LRDs.