The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) Survey Design, Reductions, and Detections

TL;DR

HETDEX is a large spectroscopic survey designed to measure redshifts of over a million Lyα emitting galaxies between redshifts 1.88 and 3.52, enabling precise cosmological measurements of the universe's expansion.

Contribution

This paper details the design, calibration, and data processing methods of HETDEX, a novel wide-field integral field spectroscopic survey targeting high-redshift galaxies.

Findings

Survey successfully detects emission-line sources with required specifications.

Achieved high astrometric accuracy and flux calibration in initial data.

Demonstrated capability to measure cosmological parameters with <1% accuracy.

Abstract

We describe the survey design, calibration, commissioning, and emission-line detection algorithms for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The goal of HETDEX is to measure the redshifts of over a million Ly$\alpha$ emitting galaxies between 1.88<z<3.52, in a 540 deg^2 area encompassing a co-moving volume of 10.9 Gpc^3. No pre-selection of targets is involved; instead the HETDEX measurements are accomplished via a spectroscopic survey using a suite of wide-field integral field units distributed over the focal plane of the telescope. This survey measures the Hubble expansion parameter and angular diameter distance, with a final expected accuracy of better than 1%. We detail the project's observational strategy, reduction pipeline, source detection, and catalog generation, and present initial results for science verification in the COSMOS, Extended Groth Strip, and GOODS-N fields. We demonstrate that our data reach the required specifications in throughput, astrometric accuracy, flux limit, and object detection, with the end products being a catalog of emission-line sources, their object classifications, and flux-calibrated spectra.