The Astrophysical Journal (Jan 2023)
The HETDEX Survey Emission-line Exploration and Source Classification
- Dustin Davis,
- Karl Gebhardt,
- Erin Mentuch Cooper,
- Robin Ciardullo,
- Maximilian Fabricius,
- Daniel J. Farrow,
- John J. Feldmeier,
- Steven L. Finkelstein,
- Eric Gawiser,
- Caryl Gronwall,
- Gary J. Hill,
- Ulrich Hopp,
- Lindsay R. House,
- Donghui Jeong,
- Wolfram Kollatschny,
- Eiichiro Komatsu,
- Martin Landriau,
- Chenxu Liu,
- Shun Saito,
- Sarah Tuttle,
- Isak G. B. Wold,
- Gregory R. Zeimann,
- Yechi Zhang
Affiliations
- Dustin Davis
- ORCiD
- Department of Astronomy, The University of Texas at Austin , 2515 Speedway Boulevard, Austin, TX 78712, USA
- Karl Gebhardt
- ORCiD
- Department of Astronomy, The University of Texas at Austin , 2515 Speedway Boulevard, Austin, TX 78712, USA
- Erin Mentuch Cooper
- ORCiD
- Department of Astronomy, The University of Texas at Austin , 2515 Speedway Boulevard, Austin, TX 78712, USA; McDonald Observatory, The University of Texas at Austin , 2515 Speedway Boulevard, Austin, TX 78712, USA
- Robin Ciardullo
- ORCiD
- Department of Astronomy & Astrophysics, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA
- Maximilian Fabricius
- ORCiD
- Max-Planck Institut für extraterrestrische Physik , Giessenbachstrasse 1, D-85748 Garching, Germany; Universitäts-Sternwarte , Fakultät für Physik, Ludwig-Maximilians Universität München, Scheinerstr. 1, D-81679 München, Germany
- Daniel J. Farrow
- ORCiD
- Max-Planck Institut für extraterrestrische Physik , Giessenbachstrasse 1, D-85748 Garching, Germany; Universitäts-Sternwarte , Fakultät für Physik, Ludwig-Maximilians Universität München, Scheinerstr. 1, D-81679 München, Germany
- John J. Feldmeier
- ORCiD
- Department of Physics, Astronomy, Geology, and Environmental Sciences, Youngstown State University Youngstown , OH 44555, USA
- Steven L. Finkelstein
- ORCiD
- Department of Astronomy, The University of Texas at Austin , 2515 Speedway Boulevard, Austin, TX 78712, USA
- Eric Gawiser
- ORCiD
- Department of Physics and Astronomy, Rutgers, The State University of New Jersey , Piscataway, NJ 08854, USA
- Caryl Gronwall
- ORCiD
- Department of Astronomy & Astrophysics, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA
- Gary J. Hill
- ORCiD
- Department of Astronomy, The University of Texas at Austin , 2515 Speedway Boulevard, Austin, TX 78712, USA; McDonald Observatory, The University of Texas at Austin , 2515 Speedway Boulevard, Austin, TX 78712, USA
- Ulrich Hopp
- ORCiD
- Max-Planck Institut für extraterrestrische Physik , Giessenbachstrasse 1, D-85748 Garching, Germany; Universitäts-Sternwarte , Fakultät für Physik, Ludwig-Maximilians Universität München, Scheinerstr. 1, D-81679 München, Germany
- Lindsay R. House
- ORCiD
- Department of Astronomy, The University of Texas at Austin , 2515 Speedway Boulevard, Austin, TX 78712, USA
- Donghui Jeong
- ORCiD
- Department of Astronomy & Astrophysics, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA
- Wolfram Kollatschny
- ORCiD
- Institut für Astrophysik, Universität Göttingen , Friedrich-Hund-Platz 1, D-37077 Göttingen, Germany
- Eiichiro Komatsu
- ORCiD
- Max-Planck-Institut für Astrophysik , Karl-Schwarzschild-Str. 1, D-85741 Garching, Germany; Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo , Kashiwanoha, Kashiwa, Chiba 277-8583, Japan
- Martin Landriau
- ORCiD
- Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USA
- Chenxu Liu
- ORCiD
- Department of Astronomy, The University of Texas at Austin , 2515 Speedway Boulevard, Austin, TX 78712, USA
- Shun Saito
- ORCiD
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo , Kashiwanoha, Kashiwa, Chiba 277-8583, Japan; Institute for Multi-messenger Astrophysics and Cosmology, Department of Physics, Missouri University of Science and Technology , 1315 N Pine St, Rolla, MO 65409, USA
- Sarah Tuttle
- ORCiD
- Department of Astronomy, University of Washington , Seattle, 3910 15th Ave NE, Room C319, Seattle, WA 98195-0002, USA
- Isak G. B. Wold
- ORCiD
- Astrophysics Science Division, Goddard Space Flight Center , Greenbelt, MD 20771, USA; Department of Physics, The Catholic University of America , Washington, DC 20064, USA; Center for Research and Exploration in Space Science and Technology , NASA/GSFC, Greenbelt, MD 20771, USA
- Gregory R. Zeimann
- ORCiD
- Hobby-Eberly Telescope, University of Texas , Austin, Austin, TX 78712, USA
- Yechi Zhang
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan; Department of Astronomy, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
- DOI
- https://doi.org/10.3847/1538-4357/acb0ca
- Journal volume & issue
-
Vol. 946,
no. 2
p. 86
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 ∼ 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 Ly α 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 α emission from the lower- z interloping galaxies, primarily [O ii ], 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 Å rest-frame equivalent width cut commonly used to distinguish LAEs from lower- z [O ii ] emitting galaxies. Despite a spectral resolving power, R ∼ 800, that cannot resolve the [O ii ] doublet, we demonstrate the ability to distinguish LAEs from foreground galaxies with 98.1% accuracy. We estimate a contamination rate of Ly α by [O ii ] of 1.2% and a Ly α recovery rate of 99.1% using the default ELiXer configuration. These rates meet the HETDEX science requirements.
Keywords
