Browsing by Author "Prieto Lyon, Gonzalo"

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    Exploring the intersection of Lyman-U Emitters & Lyman Break Galaxies behind the strongly lensed clusters : Abell370, Abell2744 and MACS0416
    (2021) Prieto Lyon, Gonzalo; Bauer, Franz Erik; Guaita, Lucía; Pontificia Universidad Católica de Chile. Instituto de Astrofísica
    In this thesis, we present a study of star-forming galaxies between redshifts 2.9-6.7 split among four categories: Pure LAEs (73 galaxies) without UV detection; Pure LBGs (1015 galaxies) without Lyman-a detection; LAE-LBGs (193 galaxies), with both Lyman break and Lyman-a detected; and Other SFGs without any of these signatures (459 galaxies). We use Multi-Unit Spectroscopic Explorer (MUSE) and legacy Hubble Space Telescope (HST) data of the three Hubble Frontier Fields lensing clusters A370, A2744 and MACS0416, reaching magnitudes as faint as M1500 ≈ −13. We study the continuum and emission-line parameters of our sample, with the goal of finding and understanding any intrinsic differences between the aforementioned regimes of SFGs. We report a great diversity of high-redshift galaxies in the Lyman-a - M1500 plane, with a lack of massive galaxies above the SFR(Lya)=SFR(UV) line at M1500 < −18, with most pure LAEs near this line and log(Llya)<42.0. We measure the UV slope of pure LBGs and LAE-LBGs, with median values of ß=-1.75 and ß=-2.44 respectively, meaning that LAEs overall are near the dust-free domain while pure LBGs tend to be redder, and hence presumably more dust-obscured and/or older, the former being one of the probable reasons for their lack of Lyman-a; SFGs without LB or Lya show redder median slopes of ß=-1.59. LAE-LBGs tend to have a stronger sSFR than pure LBGs and other SFGs by a factor of 2 at every studied redshift. We find slight differences between the two LAE populations, with LAE-LBGs showing broader Lyman-a profiles, but further radiative transfer simulations are needed to clarify the contribution of HI velocity and column density.
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    Pilot-WINGS: An extended MUSE view of the structure of Abell 370
    (2022) Lagattuta, David J.; Richard, Johan; Bauer, Franz Erik; Cerny, Catherine; Claeyssens, Adelaide; Guaita, Lucia; Jauzac, Mathilde; Jeanneau, Alexandre; Koekemoer, Anton M.; Mahler, Guillaume; Prieto Lyon, Gonzalo; Acebron, Ana; Meneghetti, Massimo; Niemiec, Anna; Zitrin, Adi; Bianconi, Matteo; Connor, Thomas; Cen, Renyue; Edge, Alastair; Faisst, Andreas L.; Limousin, Marceau; Massey, Richard; Sereno, Mauro; Sharon, Keren; Weaver, John R.
    We investigate the strong-lensing cluster Abell 370 (A370) using a wide Integral Field Unit (IFU) spectroscopic mosaic from the Multi-Unit Spectroscopic Explorer (MUSE). IFU spectroscopy provides significant insight into the structure and mass content of galaxy clusters, yet IFU-based cluster studies focus almost exclusively on the central Einstein-radius region. Covering over 14 arcmin(2), the new MUSE mosaic extends significantly beyond the A370 Einstein radius, providing, for the first time, a detailed look at the cluster outskirts. Combining these data with wide-field, multi-band Hubble Space Telescope (HST) imaging from the BUFFALO project, we analyse the distribution of objects within the cluster and along the line of sight. Identifying 416 cluster galaxies, we use kinematics to trace the radial mass profile of the halo, providing a mass estimate independent from the lens model. We also measure radially averaged properties of the cluster members, tracking their evolution as a function of infall. Thanks to the high spatial resolution of our data, we identify six cluster members acting as galaxy-galaxy lenses, which constrain localized mass distributions beyond the Einstein radius. Finally, taking advantage of MUSE's 3D capabilities, we detect and analyse multiple spatially extended overdensities outside of the cluster that influence lensing-derived halo mass estimates. We stress that much of this work is only possible thanks to the robust, extended IFU coverage, highlighting its importance even in less optically dense cluster regions. Overall, this work showcases the power of combining HST + MUSE, and serves as the initial step towards a larger and wider program targeting several clusters.