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- ItemAn atlas of MUSE observations towards twelve massive lensing clusters(Les Ulis : EDP Sciences, 2021) Richard, Johan; Claeyssens, Adélaïde; Lagattuta, David; Guaita, Lucia; Bauer, Franz Erik; Pello, Roser; Carton, David; Bacon, Roland; Soucail, Geneviève; Lyon, Gonzalo Prieto; Kneib, Jean-Paul; Mahler, Guillaume; Clément, Benjamin; Mercier, Wilfried; Variu, Andrei; Tamone, Amélie; Ebeling, Harald; Schmidt, Kasper B.; Nanayakkara, Themiya; Maseda, Michael; Weilbacher, Peter M.; Bouché, Nicolas; Bouwens, Rychard J.; Wisotzki, Lutz; de la Vieuville, Geoffroy; Martinez, Johany; Patrício, VeraContext. Spectroscopic surveys of massive galaxy clusters reveal the properties of faint background galaxies thanks to the magnification provided by strong gravitational lensing. Aims. We present a systematic analysis of integral-field-spectroscopy observations of 12 massive clusters, conducted with the Multi Unit Spectroscopic Explorer (MUSE). All data were taken under very good seeing conditions (~0".6) in effective exposure times between two and 15 h per pointing, for a total of 125 h. Our observations cover a total solid angle of ~23 arcmin2 in the direction of clusters, many of which were previously studied by the MAssive Clusters Survey, Frontier Fields (FFs), Grism Lens-Amplified Survey from Space and Cluster Lensing And Supernova survey with Hubble programmes. The achieved emission line detection limit at 5? for a point source varies between (0.77-1.5) × 10-18 erg s-1 cm-2 at 7000 Å. Methods. We present our developed strategy to reduce these observational data, detect continuum sources and line emitters in the datacubes, and determine their redshifts. We constructed robust mass models for each cluster to further confirm our redshift measurements using strong-lensing constraints, and identified a total of 312 strongly lensed sources producing 939 multiple images. Results. The final redshift catalogues contain more than 3300 robust redshifts, of which 40% are for cluster members and ∼30% are for lensed Lyman-α emitters. Fourteen percent of all sources are line emitters that are not seen in the available HST images, even at the depth of the FFs (∼29 AB). We find that the magnification distribution of the lensed sources in the high-magnification regime (μ = 2–25) follows the theoretical expectation of N(z) ∝ μ−2. The quality of this dataset, number of lensed sources, and number of strong-lensing constraints enables detailed studies of the physical properties of both the lensing cluster and the background galaxies. The full data products from this work, including the datacubes, catalogues, extracted spectra, ancillary images, and mass models, are made available to the community.
- ItemALMA and MUSE observations reveal a quiescent multi-phase circumgalactic medium around the z ≃ 3.6 radio galaxy 4C 19.71(Les Ulis : EDP Sciences, 2021) Falkendal, Theresa; Lehnert, Matthew D.; Vernet, Joël; De Breuck, Carlos; Wang, WujiWe present MUSE at VLT imaging spectroscopy of rest-frame ultraviolet emission lines and ALMA observations of the [C I] 3P1-3P0 emission line, probing both the ionized and diffuse molecular medium around the radio galaxy 4C 19.71 at z ≃ 3.6. This radio galaxy has extended Lyα emission over a region ∼100 kpc in size preferentially oriented along the axis of the radio jet. Faint Lyα emission extends beyond the radio hot spots. We also find extended C IV and He II emission over a region of ∼150 kpc in size, where the most distant emission lies ∼40 kpc beyond the north radio lobe and has narrow full width half maximum (FWHM) line widths of ∼180 km s-1 and a small relative velocity offset Δv ∼ 130 km s-1 from the systemic redshift of the radio galaxy. The [C I] is detected in the same region with FWHM ∼100 km s-1 and Δv ∼ 5 km s-1, while [C I] is not detected in the regions south of the radio galaxy. We interpret the coincidence in the northern line emission as evidence of relatively quiescent multi-phase gas residing within the halo at a projected distance of ∼75 kpc from the host galaxy. To test this hypothesis, we performed photoionization and photo-dissociated region (PDR) modeling, using the code Cloudy, of the three emission line regions: the radio galaxy proper and the northern and southern regions. We find that the [C I]/C IVλλ1548, 1551 and C IVλλ1548, 1551/He II ratios of the two halo regions are consistent with a PDR or ionization front in the circumgalactic medium likely energized by photons from the active galactic nuclei. This modeling is consistent with a relatively low metallicity, 0.03 < [Z/Z⊙] < 0.1, and diffuse ionization with an ionization parameter (proportional to the ratio of the photon number density and gas density) of log U ∼ -3 for the two circumgalactic line emission regions. Using rough mass estimates for the molecular and ionized gas, we find that the former may be tracing ≈2-4 orders of magnitude more mass. As our data are limited in signal-to-noise due to the faintness of the line, deeper [C I] observations are required to trace the full extent of this important component in the circumgalactic medium. © T. Falkendal et al. 2021.