2023, Bacon, Roland, Brinchmann, Jarle, Conseil, Simon, Maseda, Michael, Nanayakkara, Themiya, Wendt, Martin, Bacher, Raphael, Mary, David, Weilbacher, Peter M., Krajnović, Davor, Boogaard, Leindert, Bouché, Nicolas, Contini, Thierry, Epinat, Benoît, Feltre, Anna, Guo, Yucheng, Herenz, Christian, Kollatschny, Wolfram, Kusakabe, Haruka, Leclercq, Floriane, Michel-Dansac, Léo, Pello, Roser, Richard, Johan, Roth, Martin, Salvignol, Gregory, Schaye, Joop, Steinmetz, Matthias, Tresse, Laurence, Urrutia, Tanya, Verhamme, Anne, Vitte, Eloise, Wisotzki, Lutz, Zoutendijk, Sebastiaan L.

We present the second data release of the MUSE Hubble Ultra-Deep Field surveys, which includes the deepest spectroscopic survey ever performed. The MUSE data, with their 3D content, amazing depth, wide spectral range, and excellent spatial and medium spectral resolution, are rich in information. Their location in the Hubble ultra-deep field area, which benefits from an exquisite collection of ancillary panchromatic information, is a major asset. This update of the first release incorporates a new 141-h adaptive-optics-assisted MUSE eXtremely Deep Field (MXDF; 1 arcmin diameter field of view) in addition to the reprocessed 10-h mosaic (3 × 3 arcmin2) and the single 31-h deep field (1 × 1 arcmin2). All three data sets were processed and analyzed homogeneously using advanced data reduction and analysis methods. The 3σ point-source flux limit of an unresolved emission line reaches 3.1 × 10-19 and 6.3 × 10-20 erg s-1 cm-2 at 10-and 141-h depths, respectively. We have securely identified and measured the redshift of 2221 sources, an increase of 41% compared to the first release. With the exception of eight stars, the collected sample consists of 25 nearby galaxies (z < 0.25), 677 [O II] emitters (z = 0.25-1.5), 201 galaxies in the MUSE redshift desert range (z = 1.5-2.8), and 1308 Lyα emitters (z = 2.8-6.7). This represents an order of magnitude more redshifts than the collection of all spectroscopic redshifts obtained before MUSE in the Hubble ultra-deep field area (i.e., 2221 versus 292). At high redshift (z > 3), the difference is even more striking, with a factor of 65 increase (1308 versus 20). We compared the measured redshifts against three published photometric redshift catalogs and find the photo-z accuracy to be lower than the constraints provided by photo-z fitting codes. Eighty percent of the galaxies in our final catalog have an HST counterpart. These galaxies are on average faint, with a median AB F775W magnitude of 25.7 and 28.7 for the [O II] and Lyα emitters, respectively. Fits of their spectral energy distribution show that these galaxies tend to be low-mass star-forming galaxies, with a median stellar mass of 6.2 × 108 M· and a median star-formation rate of 0.4 M· yr-1. We measured the completeness of our catalog with respect to HST and found that, in the deepest 141-h area, 50% completeness is achieved for an AB magnitude of 27.6 and 28.7 (F775W) at z = 0.8-1.6 and z = 3.2-4.5, respectively. Twenty percent of our catalog, or 424 galaxies, have no HST counterpart. The vast majority of these new sources are high equivalent-width z > 2.8 Lyα emitters that are detected by MUSE thanks to their bright and asymmetric broad Lyα line. We release advanced data products, specific software, and a web interface to select and download data sets.

2023, Glikman, Eilat, Rusu, Cristian E., Chen, Geoff C.-F., Chan, James Hung-Hsu, Spingola, Cristiana, Stacey, Hannah, McKean, John, Berghea, Ciprian T., Djorgovski, S. G., Graham, Matthew J., Stern, Daniel, Urrutia, Tanya, Lacy, Mark, Secrest, Nathan J., O’Meara, John M.

We present the discovery of a gravitationally lensed dust-reddened QSO at z = 2.517, identified in a survey for QSOs by infrared selection. Hubble Space Telescope imaging reveals a quadruply lensed system in a cusp configuration, with a maximum image separation of ∼1.″8. We find that, compared to the central image of the cusp, the neighboring brightest image is anomalous by a factor of ∼7-10, which is the largest flux anomaly measured to date in a lensed QSO. Incorporating high-resolution Very Large Array radio imaging and submillimeter imaging with the Atacama Large Millimeter/submillimeter Array, we conclude that a low-mass perturber is the most likely explanation for the anomaly. The optical through near-infrared spectrum reveals that the QSO is moderately reddened with E(B − V) ≃ 0.7-0.9. We see an upturn in the ultraviolet spectrum due to ∼1% of the intrinsic emission being leaked back into the line of sight, which suggests that the reddening is intrinsic and not due to the lens. The QSO may have an Eddington ratio as high as L/L Edd ≈ 0.2. Consistent with previous red QSO samples, this source exhibits outflows in its spectrum, as well as morphological properties suggestive of it being in a merger-driven transitional phase. We find a host galaxy stellar mass of log M ⋆ / M ⊙ = 11.4 , which is higher than the local M BH versus M ⋆ relation but consistent with other high-redshift QSOs. When demagnified, this QSO is at the knee of the luminosity function, allowing for the detailed study of a more typical moderate-luminosity infrared-selected QSO at high redshift.

2023, Mentuch Cooper, Erin, Gebhardt, Karl, Davis, Dustin, Farrow, Daniel J., Liu, Chenxu, Zeimann, Gregory, Ciardullo, Robin, Feldmeier, John J., Drory, Niv, Jeong, Donghui, Benda, Barbara, Bowman, William P., Boylan-Kolchin, Michael, Chávez Ortiz, Óscar A., Debski, Maya H., Dentler, Mona, Fabricius, Maximilian, Farooq, Rameen, Finkelstein, Steven L., Gawiser, Eric, Gronwall, Caryl, Hill, Gary J., Hopp, Ulrich, House, Lindsay R., Janowiecki, Steven, Khoraminezhad, Hasti, Kollatschny, Wolfram, Komatsu, Eiichiro, Landriau, Martin, Niemeyer, Maja Lujan, Lee, Hanshin, MacQueen, Phillip, Mawatari, Ken, McKay, Brianna, Ouchi, Masami, Poppe, Jennifer, Saito, Shun, Schneider, Donald P., Snigula, Jan, Thomas, Benjamin P., Tuttle, Sarah, Urrutia, Tanya, Weiss, Laurel, Wisotzki, Lutz, Zhang, Yechi

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 Lyα-emitting galaxies over a total target area of 540 deg2. The catalog comes from contiguous fiber spectra coverage of 25 deg2 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 Lyα-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 Lyα 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 Δz < 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.