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1. HETDEX Public Source Catalog 1: 220 K Sources Including Over 50 K Lyα Emitters from an Untargeted Wide-area Spectroscopic Survey*

   https://doi.org/10.3847/1538-4357/aca962  

   Mentuch Cooper, Erin ; Gebhardt, Karl ; Davis, Dustin ; Farrow, Daniel J. ; Liu, Chenxu ; Zeimann, Gregory ; Ciardullo, Robin ; Feldmeier, John J. ; Drory, Niv ; Jeong, Donghui ; et al ( February 2023 , The Astrophysical Journal)

   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 sample 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 sample. Data access and details about the catalog can be found online at http://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 . 

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2. The Active Galactic Nuclei in the Hobby–Eberly Telescope Dark Energy Experiment Survey (HETDEX). I. Sample Selection

   https://doi.org/10.3847/1538-4365/ac6ba6  

   Liu, Chenxu ; Gebhardt, Karl ; Cooper, Erin Mentuch ; Davis, Dustin ; Schneider, Donald P. ; Ciardullo, Robin ; Farrow, Daniel J. ; Finkelstein, Steven L. ; Gronwall, Caryl ; Guo, Yuchen ; et al ( July 2022 , The Astrophysical Journal Supplement Series)

   We present the first active galactic nuclei (AGN) catalog of the Hobby–Eberly Telescope Dark Energy Experiment Survey (HETDEX) observed between 2017 January and 2020 June. HETDEX is an ongoing spectroscopic survey (3500–5500 Å) with no target preselection based on magnitudes, colors or morphologies, enabling us to select AGN based solely on their spectral features. Both luminous quasars and low-luminosity Seyferts are found in our catalog. AGN candidates are selected with at least two significant AGN emission lines, such as the Lyαand Civλ1549 line pair, or with a single broad emission line with FWHM > 1000 km s⁻¹. Each source is further confirmed by visual inspections. This catalog contains 5322 AGN, covering an effective sky coverage of 30.61 deg². A total of 3733 of these AGN have secure redshifts, and we provide redshift estimates for the remaining 1589 single broad-line AGN with no crossmatched spectral redshifts from the Sloan Digital Sky Survey Data Release 14 of QSOs. The redshift range of the AGN catalog is 0.25 <z< 4.32, with a median ofz= 2.1. The bolometric luminosity range is 10⁹–10¹⁴L_☉with a median of 10¹²L_☉. The medianr-band magnitude of our AGN catalog is 21.6 mag, with 34% havingr> 22.5, and 2.6% reaching the detection limit atr∼ 26 mag of the deepest imaging surveys we searched. We also provide a composite spectrum of the AGN sample covering 700–4400 Å.

    

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3. The UNCOVER Survey: A First-look HST + JWST Catalog of 60,000 Galaxies near A2744 and beyond

   https://doi.org/10.3847/1538-4365/ad07e0  

   Weaver, John R. ; Cutler, Sam E. ; Pan, Richard ; Whitaker, Katherine E. ; Labbé, Ivo ; Price, Sedona H. ; Bezanson, Rachel ; Brammer, Gabriel ; Marchesini, Danilo ; Leja, Joel ; et al ( December 2023 , The Astrophysical Journal Supplement Series)

   In 2022 November, the James Webb Space Telescope (JWST) returned deep near-infrared images of A2744—a powerful lensing cluster capable of magnifying distant, incipient galaxies beyond it. Together with existing Hubble Space Telescope (HST) imaging, this publicly available data set opens a fundamentally new discovery space to understand the remaining mysteries of the formation and evolution of galaxies across cosmic time. In this work, we detect and measure some 60,000 objects across the 49 arcmin²JWST footprint down to a 5σlimiting magnitude of ∼30 mag in 0.″32 apertures. Photometry is performed using circular apertures on images matched to the point-spread function (PSF) of the reddest NIRCam broad band, F444W, and cleaned of bright cluster galaxies and the related intracluster light. To give an impression of the photometric performance, we measure photometric redshifts and achieve aσ_NMAD≈ 0.03 based on known, but relatively small, spectroscopic samples. With this paper, we publicly release our HST and JWST PSF-matched photometric catalog with optimally assigned aperture sizes for easy use, along with single aperture catalogs, photometric redshifts, rest-frame colors, and individual magnification estimates. These catalogs will set the stage for efficient and deep spectroscopic follow up of some of the first JWST-selected samples in summer of 2023.

    

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4. Measuring Cosmological Parameters with Type Ia Supernovae in redMaGiC Galaxies

   https://doi.org/10.3847/1538-4357/ac8b82  

   Chen, R. ; Scolnic, D. ; Rozo, E. ; Rykoff, E. S. ; Popovic, B. ; Kessler, R. ; Vincenzi, M. ; Davis, T. M. ; Armstrong, P. ; Brout, D. ; et al ( October 2022 , The Astrophysical Journal)

   Current and future cosmological analyses with Type Ia supernovae (SNe Ia) face three critical challenges: (i) measuring the redshifts from the SNe or their host galaxies; (ii) classifying the SNe without spectra; and (iii) accounting for correlations between the properties of SNe Ia and their host galaxies. We present here a novel approach that addresses each of these challenges. In the context of the Dark Energy Survey (DES), we analyze an SN Ia sample with host galaxies in the redMaGiC galaxy catalog, a selection of luminous red galaxies. redMaGiC photo-zestimates are expected to be accurate toσ_Δz/(1+z)∼ 0.02. The DES-5YR photometrically classified SN Ia sample contains approximately 1600 SNe, and 125 of these SNe are in redMaGiC galaxies. We demonstrate that redMaGiC galaxies almost exclusively host SNe Ia, reducing concerns relating to classification uncertainties. With this subsample, we find similar Hubble scatter (to within ∼0.01 mag) using photometric redshifts in place of spectroscopic redshifts. With detailed simulations, we show that the bias due to using redMaGiC photo-zs on the measurement of the dark energy equation of statewis up to Δw∼ 0.01–0.02. With real data, we measure a difference inwwhen using the redMaGiC photo-zs versus the spec-zs of Δw= 0.005. Finally, we discuss how SNe in redMaGiC galaxies appear to comprise a more standardizable population, due to a weaker relation between color and luminosity (β) compared to the DES-3YR population by ∼5σ. These results establish the feasibility of performing redMaGiC SN cosmology with photometric survey data in the absence of spectroscopic data.

    

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5. The Active Galactic Nuclei in the Hobby–Eberly Telescope Dark Energy Experiment Survey (HETDEX). II. Luminosity Function

   https://doi.org/10.3847/1538-4357/ac8054  

   Liu, Chenxu ; Gebhardt, Karl ; Cooper, Erin Mentuch ; Zhang, Yechi ; Schneider, Donald P. ; Ciardullo, Robin ; Davis, Dustin ; Farrow, Daniel J. ; Finkelstein, Steven L. ; Gronwall, Caryl ; et al ( August 2022 , The Astrophysical Journal)

   We present the Lyαemission line luminosity function (LF) of the active galactic nuclei (AGN) in the first release of the Hobby–Eberly Telescope Dark Energy Experiment Survey (HETDEX) AGN catalog. The AGN are selected either by emission line pairs characteristic of AGN or by a single broad emission line, free of any photometric preselections (magnitude/color/morphology). The sample consists of 2346 AGN spanning 1.88 <z< 3.53, covering an effective area of 30.61 deg². Approximately 2.6% of the HETDEX AGN are not detected at >5σconfidence atr∼ 26 in the deepestr-band images we have searched. The Lyαline luminosity ranges from ∼10^42.3to 10^45.9erg s⁻¹. Our LyαLF shows a turnover luminosity with opposite slopes on the bright end and the faint end: The space density is highest at$L_{\text{Ly}\mathit{\text{α}}}^{\ast }={10}^{43.4}$erg s⁻¹. We explore the evolution of the AGN LF over a broader redshift range (0.8 <z< 3); constructing the rest-frame ultraviolet (UV) LF with the 1450 Å monochromatic luminosity of the power-law component of the continuum (M₁₄₅₀) fromM₁₄₅₀∼ −18 to −27.5. We divide the sample into three redshift bins (z∼ 1.5, 2.1, and 2.6). In all three redshift bins, our UV LFs indicate that the space density of AGN is highest at the turnover luminosity$M_{1450}^{*}$with opposite slopes on the bright end and the faint end. TheM₁₄₅₀LFs in the three redshift bins can be well fit with a luminosity evolution and density evolution model: the turnover luminosity ($M_{1450}^{*}$) increases, and the turnover density (Φ*) decreases with increasing redshift.

    

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