Speaker
Description
Lyα emitters (LAEs), characterized by their prominent Lyα emission at 1216 Å, are key tracers of high-redshift galaxies and play a crucial role in our understanding of galaxy evolution and cosmic reionization. In particular, radio-detected LAEs offer valuable insights into the interplay between star formation, active galactic nuclei (AGN) activity, and the interstellar medium.
Using the HETDEX–LOFAR spectroscopic catalog, which combines spectroscopic redshifts from HETDEX DR4 with radio data from LOFAR DR1, we identify 400 robust Lyα+radio sources in the redshift range $1.88 < z < 3.52$, selected from a parent sample of 79,022 LAEs and 28,705 radio sources. After correcting for completeness, we find a radio-detected AGN fraction of $1.67 \pm 0.33%$ among LAEs and a Lyα-emitting fraction of $23.76 \pm 4.76%$ among radio sources. Both fractions increase with Lyα and radio luminosity.
We observe weak correlations between luminosity, redshift, and Lyα line width. A small subset of resolved radio galaxies, with projected radio sizes ranging from 141 to 502 kpc, highlights the diversity of Lyα environments.
Our results confirm that the majority of LAEs are star-forming and radio-quiet, while a luminous minority host AGN. The presence of Lyα emission in some radio AGN suggests ongoing interaction with cold gas, indicating a complex interplay between AGN feedback, gas dynamics, and galaxy evolution at high redshift.
