We combine the power of blind integral field spectroscopy from the Hobby-Eberly Telescope (HET) Dark Energy Experiment (HETDEX) with sources detected by the Low Frequency Array (LOFAR) to construct the HETDEX-LOFAR Spectroscopic Redshift Catalog. Starting from the first data release of the LOFAR Two-metre Sky Survey (LoTSS), including a value-added catalog with photometric redshifts, we extracted 28,705 HETDEX spectra. Using an automatic classifying algorithm, we assigned each object a star, galaxy, or quasar label along with a velocity/redshift, with supplemental classifications coming from the continuum and emission line catalogs of the internal, fourth data release from HETDEX (HDR4). We measured 9,087 new redshifts; in combination with the value-added catalog, our final spectroscopic redshift sample is 9,710 sources. This new catalog contains the highest substantial fraction of LOFAR galaxies with spectroscopic redshift information; it improves archival spectroscopic redshifts, and facilitates research to determine the [O II] emission properties of radio galaxies from 0.0<z<0.5, and the Lyα emission characteristics of both radio galaxies and quasars from 1.9<z<3.5. Additionally, by combining the unique properties of LOFAR and HETDEX, we are able to measure star formation rates (SFR) and stellar masses. Using the Visible Integral-field Replicable Unit Spectrograph (VIRUS), we measure the emission lines of [O III], [Ne III], and [O II] and evaluate line-ratio diagnostics to determine whether the emission from these galaxies is dominated by AGN or star formation and fit a new SFR-L150MHz relationship.
@article{arxiv.2411.08974,
title = {HETDEX-LOFAR Spectroscopic Redshift Catalog},
author = {Maya H. Debski and Gregory R. Zeimann and Gary J. Hill and Donald P. Schneider and Leah Morabito and Gavin Dalton and Matt J. Jarvis and Erin Mentuch Cooper and Robin Ciardullo and Eric Gawiser and Nika Jurlin},
journal= {arXiv preprint arXiv:2411.08974},
year = {2024}
}