ORCID Profile
0000-0002-0417-1494
Current Organisation
University of Goettingen
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: EDP Sciences
Date: 10-2021
DOI: 10.1051/0004-6361/202140876
Abstract: Rest-frame ultraviolet (UV) emission lines probe electron densities, gas-phase abundances, metallicities, and ionization parameters of the emitting star-forming galaxies and their environments. The strongest main UV emission line, Ly α , has been instrumental in advancing the general knowledge of galaxy formation in the early universe. However, observing Ly α emission becomes increasingly challenging at z ≳ 6 when the neutral hydrogen fraction of the circumgalactic and intergalactic media increases. Secondary weaker UV emission lines provide important alternative methods for studying galaxy properties at high redshift. We present a large s le of rest-frame UV emission line sources at intermediate redshift for calibrating and exploring the connection between secondary UV lines and the emitting galaxies’ physical properties and their Ly α emission. The s le of 2052 emission line sources with 1.5 z 6.4 was collected from integral field data from the MUSE-Wide and MUSE-Deep surveys taken as part of Guaranteed Time Observations. The objects were selected through untargeted source detection (i.e., no preselection of sources as in dedicated spectroscopic c aigns) in the three-dimensional MUSE data cubes. We searched optimally extracted one-dimensional spectra of the full s le for UV emission features via emission line template matching, resulting in a s le of more than 100 rest-frame UV emission line detections. We show that the detection efficiency of (non-Ly α ) UV emission lines increases with survey depth, and that the emission line strength of He II λ 1640 Å, [O III ] λ 1661 + O III ] λ 1666, and [Si III ] λ 1883 + Si III ] λ 1892 correlate with the strength of [C III ] λ 1907 + C III ] λ 1909. The rest-frame equivalent width (EW 0 ) of [C III ] λ 1907 + C III ] λ 1909 is found to be roughly 0.22 ± 0.18 of EW 0 (Ly α ). We measured the velocity offsets of resonant emission lines with respect to systemic tracers. For C IV λ 1548 + C IV λ 1551 we find that Δ v C IV ≲ 250 km s −1 , whereas Δ v Ly α falls in the range of 250−500 km s −1 which is in agreement with previous results from the literature. The electron density n e measured from [Si III ] λ 1883 + Si III ] λ 1892 and [C III ] λ 1907 + C III ] λ 1909 line flux ratios is generally 10 5 cm −3 and the gas-phase abundance is below solar at 12 + log 10 (O/H)≈8. Lastly, we used “PhotoIonization Model Probability Density Functions” to infer physical parameters of the full s le and in idual systems based on photoionization model parameter grids and observational constraints from our UV emission line searches. This reveals that the UV line emitters generally have ionization parameter log 10 (U) ≈ −2.5 and metal mass fractions that scatter around Z ≈ 10 −2 , that is Z ≈ 0.66 Z ⊙ . Value-added catalogs of the full s le of MUSE objects studied in this work and a collection of UV line emitters from the literature are provided with this paper.
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 .
No related grants have been discovered for Wolfram Kollatschny.