The HETDEX Survey: Emission Line Exploration and Source Classification

Abstract

The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is an untargeted spectroscopic survey that aims to measure the expansion rate of the Universe at $z\sim 2.4$ to 1% precision for both $H(z)$ and $D_A(z)$. HETDEX is in the process of mapping in excess of one million Lyman Alpha emitting (LAE) galaxies and a similar number of lower-z galaxies as a tracer of the large-scale structure. The success of the measurement is predicated on the post-observation separation of galaxies with Ly$\alpha$ emission from the lower-$z$ interloping galaxies, primarily [OII], with low contamination and high recovery rates. The Emission Line eXplorer (ELiXer) is the principal classification tool for HETDEX, providing a tunable balance between contamination and completeness as dictated by science needs. By combining multiple selection criteria, ELiXer improves upon the 20 Angstrom rest-frame equivalent width cut commonly used to distinguish LAEs from lower-$z$ [OII] emitting galaxies. Despite a spectral resolving power, R $\sim 800$, that cannot resolve the [OII] doublet, we demonstrate the ability to distinguish LAEs from foreground galaxies with 98.1% accuracy. We estimate a contamination rate of Ly$\alpha$ by [OII] of 1.2% and a Ly$\alpha$ recovery rate of 99.1% using the default ELiXer configuration. These rates meet the HETDEX science requirements.

arXiv comment38 pages, 11 figures

References in corpus (63)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• emcee: The MCMC Hammer
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological analysis of the DR12 galaxy sample
• A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncertainty from the Hubble Space Telescope and the SH0ES Team
• CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey
• CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey - The Hubble Space Telescope Observations, Imaging Data Products and Mosaics
• High Redshift Galaxies in the Hubble Deep Field. Color Selection and Star Formation History to z=4
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• In the Realm of the Hubble tension $-$ a Review of Solutions
• Overview of the DESI Legacy Imaging Surveys
• Planck 2018 results. I. Overview and the cosmological legacy of Planck
• Radiative Transfer in a Clumpy Universe: II. The Utraviolet Extragalactic Background
• The Sixteenth Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory
• Rest-Frame Ultraviolet Spectra of z~3 Lyman Break Galaxies
• The COSMOS2015 Catalog: Exploring the 1<z<6 Universe with half a million galaxies
• The Dark Energy Survey: more than dark energy - an overview
• A Redetermination of the Hubble Constant with the Hubble Space Telescope from a Differential Distance Ladder
• The Atacama Cosmology Telescope: DR4 Maps and Cosmological Parameters
• Spectroscopic Confirmation of a Population of Normal Star-Forming Galaxies at Redshifts z>3
• The Hyper Suprime-Cam Software Pipeline
• Keck Spectroscopy of Faint 3<z<7 Lyman Break Galaxies: - I. New constraints on cosmic reionisation from the luminosity and redshift-dependent fraction of Lyman-alpha emission
• Third Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• Ly-alpha Emission-Line Galaxies at z = 3.1 in the Extended Chandra Deep Field South
• Ly Alpha-Emitting Galaxies at z=3.1: L* Progenitors Experiencing Rapid Star Formation
• The Keck Lyman Continuum Spectroscopic Survey (KLCS): The Emergent Ionizing Spectrum of Galaxies at $z\sim 3$
• High-z Lyman-alpha Emitters. I. A Blank-Field Search for Objects Near Redshift z=3.4 in and around the Hubble Deep Field and the Hawaii Deep Field SSA22
• CANDELS Multiwavelength Catalogs: Source Identification and Photometry in the CANDELS Extended Groth Strip
• The CANDELS/SHARDS multi-wavelength catalog in GOODS-N: Photometry, Photometric Redshifts, Stellar Masses, Emission line fluxes and Star Formation Rates
• Direct Lyman continuum and Lyman-alpha escape observed at redshift 4
• The HETDEX Pilot Survey. II. The Evolution of the Ly-alpha Escape Fraction from the UV Slope and Luminosity Function of 1.9<z<3.8 LAEs
• Measuring the Hubble constant with Type Ia supernovae as near-infrared standard candles
• The Relationship Between Stellar Populations and Lyman Alpha Emission in Lyman Break Galaxies
• HETDEX pilot survey for emission-line galaxies - I. Survey design, performance, and catalog
• The HETDEX Instrumentation: Hobby-Eberly Telescope Wide Field Upgrade and VIRUS
• Colour corrections for high redshift objects due to intergalactic attenuation
• Recovering the systemic redshift of galaxies from their Lyman-alpha line profile
• The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) Survey Design, Reductions, and Detections
• First spectroscopic measurements of [OIII] emission from Lyman-alpha selected field galaxies at z ~ 3.1
• A Step in Understanding the Hubble Tension
• The Hubble Tension Revisited: Additional Local Distance Ladder Uncertainties
• The Millennium Run Observatory: First Light
• The HETDEX Pilot Survey. IV. The Evolution of [O II] Emitting Galaxies from z ~ 0.5 to z ~ 0
• The [OII]3727 Luminosity Function of the Local Universe
• HETDEX Public Source Catalog 1: 220K Sources Including Over 50K Lyman Alpha Emitters from an Untargeted Wide-area Spectroscopic Survey
• Overview of the Dark Energy Spectroscopic Instrument
• The Synthetic Emission Line COSMOS catalog: H$\alpha$ and [OII] galaxy luminosity functions and counts at $0.3<z<2.5$
• To Stack or Not to Stack: Spectral Energy Distribution Properties of Lya-Emitting Galaxies at z=2.1
• The evolution of the [OII], Hβ and [OIII] emission-line luminosity functions over the last nine billions years
• Bayesian Redshift Classification of Emission-line Galaxies with Photometric Equivalent Widths
• Correcting correlation functions for redshift-dependent interloper contamination
• The Spitzer-HETDEX Exploratory Large Area Survey II: Dark Energy Camera and Spitzer/IRAC Multiwavelength Catalog
• Clustering at high redshift: The connection between Lyman Alpha emitters and Lyman break galaxies
• Unbiased Cosmological Parameter Estimation from Emission Line Surveys with Interlopers
• ZELDA: fitting Lyman-alpha line profiles using deep learning
• The Active Galactic Nuclei in the Hobby-Eberly Telescope Dark Energy Experiment Survey (HETDEX) I. Sample selection
• The evolution of the UV luminosity and stellar mass functions of Lyman-alpha emitters from z~2 to z~6
• Luminosity function of [OII] emission-line galaxies in the MassiveBlack-II simulation
• Universal conditional distribution function of [OII] luminosity of galaxies, and prediction for the [OII] luminosity function at redshift $z<3$

Cited by in corpus (12)

• Introducing the Texas Euclid Survey for Lyman Alpha (TESLA) Survey: Initial Study Correlating Galaxy Properties to Lyman-Alpha Emission
• HETDEX Public Source Catalog 1 -- Stacking 50K Lyman Alpha Emitters
• Using Dark Energy Explorers and Machine Learning to Enhance the Hobby-Eberly Telescope Dark Energy Experiment
• Precise self-calibration of interloper bias in spectroscopic surveys
• The miniJPAS & J-NEP surveys: Identification and characterization of the Ly$\alpha$ Emitter population and the Ly$\alpha$ Luminosity Function
• Using Lyman Alpha Absorption to Measure the Intensity and Variability of $z\sim 2.4$ Ultraviolet Background Light
• Participatory Science and Machine Learning Applied to Millions of Sources in the Hobby-Eberly Telescope Dark Energy Experiment
• Lyα Intensity Mapping in HETDEX: Galaxy-Lyα Intensity Cross-Power Spectrum
• Cosmological-Scale Lyman-alpha Forest Absorption Around Galaxies and AGN Probed with the HETDEX and SDSS Spectroscopic Data
• HETDEX Public Data Release 1: Source Catalog 2 and Data Cubes from ~90 sq deg of Integral-Field Optical Spectroscopy
• Golden and Silver Dark Sirens for precise H0 measurement with HETDEX
• A gradient boosting and broadband approach to finding Lyman-α emitting galaxies beyond narrowband surveys