Stellar Populations of Lyman-alpha Emitting Galaxies in the HETDEX Survey I: An Analysis of LAEs in the GOODS-N Field

TL;DR

This study analyzes the stellar populations of Lyman-alpha emitting galaxies in the GOODS-N field using HETDEX data, revealing correlations between galaxy properties and Lyman-alpha emission, and exploring predictions for high-redshift galaxies.

Contribution

It introduces a method to connect spectroscopic detections with imaging data in large surveys and compares properties of LAEs across different selection techniques.

Findings

Median stellar mass of LAEs is approximately 0.8 billion solar masses.

Stellar mass and star formation rate strongly correlate with Lyman-alpha equivalent width.

Predictions of Lyman-alpha emission for high-redshift galaxies show good agreement with observations.

Abstract

We present the results of a stellar-population analysis of Lyman-alpha emitting galaxies (LAES) in GOODS-N at 1.9 < z < 3.5 spectroscopically identified by the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). We provide a method for connecting emission-line detections from the blind spectroscopic survey to imaging counterparts, a crucial tool needed as HETDEX builds a massive database of ~1 million Lyman-alpha detections. Using photometric data spanning as many as 11 filters covering 0.4-4.5 microns from the Hubble and Spitzer Space Telescopes, we study the objects' global properties and explore which properties impact the strength of Lyman-alpha emission. We measure a median stellar mass of 0.8 (^+2.9_-0.5) x 10^9 Msol and conclude that the physical properties of HETDEX spectroscopically-selected LAEs are comparable to LAEs selected by previous deep narrow band studies. We find that stellar mass and star formation rate correlate strongly with the Lyman-alpha equivalent width. We then use a known sample of z>7 LAEs to perform a proto-study of predicting Lyman-alpha emission from galaxies in the Epoch of Reionization, finding agreement at the 1-sigma level between prediction and observation for the majority of strong emitters.