HETDEX Public Source Catalog 2 (HPSC2) from HETDEX Public Data Release 1

The HETDEX Source Catalog 2 (HPSC2) is part of the HETDEX Public Data Release 1 (PDR1), providing a large, uniformly processed catalog of sources detected in the completed Hobby–Eberly Telescope Dark Energy Experiment (HETDEX). HETDEX is a wide-field, integral-field spectroscopic survey designed to map the large-scale distribution of Lyman-alpha emitting galaxies (LAEs) at 1.88 < z < 3.52. The survey uses the VIRUS instrument on the Hobby–Eberly Telescope to obtain over one hundred thousand spectra per exposure, enabling an untargeted census of emission-line galaxies. HPSC2 includes classifications, redshifts, and spectra for over one million sources, including 426,654 Lyman-alpha emitters (LAEs), 491,411 [O II] emitters, 150,608 stars, 19,457 low-redshift galaxies (LzG), and 18,303 AGN. The catalog is constructed from PSF-weighted spectral extractions and includes machine-learning classifications and quality metrics. It is organised into two complementary tables. The Source Observation Table provides one row per unique source observation, restricted to sources passing the primary catalog quality cuts (p_conf ≥ 0.5 and p_cnn ≥ 0.5). The Detection Information Table is the expanded catalog with one row per emission-line or continuum detection, including detections below the primary threshold. Several detections can comprise a single source observation. Data Repository Contents Filename Description hetdex_sc2_v1.5.fits Source Observation Table (FITS) - Main Catalog. Contains a sub-selection of p_conf ≥ 0.5 and p_cnn ≥ 0.5 emission-line candidates. Note continuum (det_type='cont') sources have sn=0 so be careful selecting on this column. hetdex_sc2_v1.5.dat Source Observation Table (ASCII) hetdex_sc2_spec_v1.5.fits Source Observation Table + 1D Spectra (FITS); HDUs: INFO, SPEC, SPEC_ERR, WAVELENGTH hetdex_sc2_detinfo_v1.5.fits Detection Information Table (FITS) hetdex_sc2_detinfo_v1.5.dat Detection Information Table (ASCII) readme Full column descriptions for both tables 10-HETDEX-Source-Catalog.ipynb A Jupyter notebook demonstrating how to work with this catalog Bad values are -999.0 for floating-point columns and 'n/a' for string columns. HETDEX Data Access Description is provided at:https://hetdex.org/data-results/ Full PDR1 data products (including IFU datacubes) are available at:https://web.corral.tacc.utexas.edu/hetdex/HETDEX/pdr/pdr1/ Datacube access and analysis tools:https://github.com/HETDEX/dexcube Preferred Citation & Acknowledgements If you use this catalog, please cite: Mentuch Cooper et al. 2026, ApJS, XXX, XXX doi:10.3847/1538-4365/ae6068Gebhardt et al. 2021, ApJ, 923, 217 doi:10.3847/1538-4357/ac2e03 Please include the following acknowledgement when using HETDEX data: HETDEX is led by the University of Texas at Austin McDonald Observatory and Department of Astronomy with participation from the Ludwig-Maximilians-Universität München, Max-Planck-Institut für Extraterrestrische Physik (MPE), Leibniz-Institut für Astrophysik Potsdam (AIP), Texas A&M University, Pennsylvania State University, Institut für Astrophysik Göttingen, The University of Oxford, Max-Planck-Institut für Astrophysik (MPA), The University of Tokyo and Missouri University of Science and Technology. Based on observations obtained with the Hobby-Eberly Telescope (HET), which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Ludwig-Maximillians-Universitaet Muenchen, and Georg-August Universitaet Goettingen. The HET is named in honor of its principal benefactors, William P. Hobby and Robert E. Eberly.