ORCID Profile
0000-0002-2307-0146
Current Organisation
The University of Texas at Austin
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Astronomical Society
Date: 12-2021
Abstract: The Hobby–Eberly Telescope (HET) Dark Energy Experiment (HETDEX) is undertaking a blind wide-field low-resolution spectroscopic survey of 540 deg 2 of sky to identify and derive redshifts for a million Ly α -emitting galaxies in the redshift range 1.9 z 3.5. The ultimate goal is to measure the expansion rate of the universe at this epoch, to sharply constrain cosmological parameters and thus the nature of dark energy. A major multiyear Wide-Field Upgrade (WFU) of the HET was completed in 2016 that substantially increased the field of view to 22′ diameter and the pupil to 10 m, by replacing the optical corrector, tracker, and Prime Focus Instrument Package and by developing a new telescope control system. The new, wide-field HET now feeds the Visible Integral-field Replicable Unit Spectrograph (VIRUS), a new low-resolution integral-field spectrograph (LRS2), and the Habitable Zone Planet Finder, a precision near-infrared radial velocity spectrograph. VIRUS consists of 156 identical spectrographs fed by almost 35,000 fibers in 78 integral-field units arrayed at the focus of the upgraded HET. VIRUS operates in a bandpass of 3500−5500 Å with resolving power R ≃ 800. VIRUS is the first ex le of large-scale replication applied to instrumentation in optical astronomy to achieve spectroscopic surveys of very large areas of sky. This paper presents technical details of the HET WFU and VIRUS, as flowed down from the HETDEX science requirements, along with experience from commissioning this major telescope upgrade and the innovative instrumentation suite for HETDEX.
Publisher: American Astronomical Society
Date: 07-2021
Publisher: American Astronomical Society
Date: 28-06-2007
DOI: 10.1086/520575
Publisher: American Astronomical Society
Date: 11-2007
DOI: 10.1086/521138
Publisher: American Astronomical Society
Date: 09-11-2009
Publisher: SPIE
Date: 12-07-2008
DOI: 10.1117/12.789692
Publisher: American Astronomical Society
Date: 06-09-2011
Publisher: American Astronomical Society
Date: 13-08-2012
Publisher: American Astronomical Society
Date: 18-07-2014
Publisher: American Astronomical Society
Date: 08-06-2016
Publisher: American Astronomical Society
Date: 02-2023
Abstract: We present the first publicly released catalog of sources obtained from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). HETDEX is an integral field spectroscopic survey designed to measure the Hubble expansion parameter and angular diameter distance at 1.88 z 3.52 by using the spatial distribution of more than a million Ly α -emitting galaxies over a total target area of 540 deg 2 . The catalog comes from contiguous fiber spectra coverage of 25 deg 2 of sky from 2017 January through 2020 June, where object detection is performed through two complementary detection methods: one designed to search for line emission and the other a search for continuum emission. The HETDEX public release catalog is dominated by emission-line galaxies and includes 51,863 Ly α -emitting galaxy (LAE) identifications and 123,891 [O ii ]-emitting galaxies at z 0.5. Also included in the catalog are 37,916 stars, 5274 low-redshift ( z 0.5) galaxies without emission lines, and 4976 active galactic nuclei. The catalog provides sky coordinates, redshifts, line identifications, classification information, line fluxes, [O ii ] and Ly α line luminosities where applicable, and spectra for all identified sources processed by the HETDEX detection pipeline. Extensive testing demonstrates that HETDEX redshifts agree to within Δ z 0.02, 96.1% of the time to those in external spectroscopic catalogs. We measure the photometric counterpart fraction in deep ancillary Hyper Suprime-Cam imaging and find that only 55.5% of the LAE s le has an r -band continuum counterpart down to a limiting magnitude of r ∼ 26.2 mag (AB) indicating that an LAE search of similar sensitivity to HETDEX with photometric preselection would miss nearly half of the HETDEX LAE catalog s le. Data access and details about the catalog can be found online at hetdex.org/ . A copy of the catalogs presented in this work (Version 3.2) is available to download at Zenodo doi: 10.5281/zenodo.7448504 .
Publisher: American Astronomical Society
Date: 15-03-2012
Publisher: American Astronomical Society
Date: 05-2021
Abstract: In this work, we measure the Ly α escape fraction of 935 [O iii ]-emitting galaxies between 1.9 z 2.35 by comparing stacked spectra from the Hubble Space Telescope/WFC3's near-IR grism to corresponding stacks from the Hobby–Eberly Telescope Dark Energy Experiment’s Internal Data Release 2. By measuring the stacks’ H β to Ly α ratios, we determine the Ly α escape fraction as a function of stellar mass, star-formation rate, internal reddening, size, and [O iii ]/H β ratio. We show that the escape fraction of Ly α correlates with a number of parameters, such as galaxy size, star-formation rate, and nebular excitation. However, we also demonstrate that most of these relations are indirect, and that the primary variables controlling the escape of Ly α are likely to be stellar mass and internal extinction. Overall, the escape of Ly α declines from ≳16% in galaxies with to ≲1% for systems with , with the s le’s mean escape fraction being .
Publisher: American Astronomical Society
Date: 29-08-2017
Publisher: American Astronomical Society
Date: 12-2021
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 α emitting galaxies between 1.88 z 3.52, in a 540 deg 2 area encompassing a comoving volume of 10.9 Gpc 3 . No preselection 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 Cosmological Evolution Survey, Extended Groth Strip, and Great Observatories Origins Deep Survey North 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.
Publisher: Oxford University Press (OUP)
Date: 12-2011
Publisher: American Astronomical Society
Date: 27-03-2009
No related grants have been discovered for Erin Mentuch Cooper.