The Lensed Lyman-Alpha MUSE Arcs Sample (LLAMAS)

Astronomy and Astrophysics, vol. 666, pp. A78

Abstract

Aims. We present the Lensed Lyman-Alpha MUSE Arcs Sample (LLAMAS) selected from MUSE and HST observations of 17 lensing clusters. The sample consists of 603 continuum-faint (−23 < MUV < −14) lensed Lyman-α emitters (producing 959 images) with secure spectroscopic redshifts between 2.9 and 6.7. Combining the power of cluster magnification with 3D spectroscopic observations, we were able to reveal the resolved morphological properties of 268 Lyman-α emitters. Methods. We used a forward-modeling approach to model both Lyman-α and rest-frame UV continuum emission profiles in the source plane and measure spatial extent, ellipticity, and spatial offsets between UV and Lyman-α emission. Results. We find a significant correlation between UV continuum and Lyman-α spatial extent. Our characterization of the Lyman-α halos indicates that the halo size is linked to the physical properties of the host galaxy (SFR, Lyman-α equivalent width, Lyman-α line FWHM). We find that 48% of Lyman-α halos are best fit by an elliptical emission distribution with a median axis ratio of q = 0.48. We observe that 60% of galaxies detected both in UV and Lyman-α emission show a significant spatial offset (ΔLyα − UV). We measure a median offset of ΔLyα − UV = 0.58 ± 0.14 kpc for the entire sample. By comparing the spatial offset values with the size of the UV component, we show that 40% of the offsets could be due to star-forming sub-structures in the UV component, while the larger offsets (60%) are more likely due to greater-distance processes such as scattering effects inside the circumgalactic medium or emission from faint satellites or merging galaxies. Comparisons with a zoom-in radiative hydrodynamics simulation of a typical Lyman-α emitting galaxy show a very good agreement with LLAMAS galaxies and indicate that bright star-formation clumps and satellite galaxies could produce a similar spatial offset distribution.

Authors 20

1. Adélaïde Claeyssens

   Lyon 1 Université · Centre National de la Recherche Scientifique · Centre de Recherche Astrophysique de Lyon

   Affiliation as printed

   University Lyon 1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, 69230, Saint-Genis-Laval, France

2. Johan Richard

   Lyon 1 Université · Centre National de la Recherche Scientifique · Centre de Recherche Astrophysique de Lyon

   Affiliation as printed

   University Lyon 1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, 69230, Saint-Genis-Laval, France

3. Jérémy Blaizot

   Lyon 1 Université · Centre National de la Recherche Scientifique · Centre de Recherche Astrophysique de Lyon

   Affiliation as printed

   University Lyon 1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, 69230, Saint-Genis-Laval, France

4. Thibault Garel

   University of Geneva

   Affiliation as printed

   Observatoire de Genève, Université de Genève, 51 Chemin de Pégase, 1290 Versoix, Switzerland

5. Haruka Kusakabe

   University of Geneva

   Affiliation as printed

   Observatoire de Genève, Université de Genève, 51 Chemin de Pégase, 1290 Versoix, Switzerland

6. Roland M. Bacon

   Lyon 1 Université · Centre National de la Recherche Scientifique · Centre de Recherche Astrophysique de Lyon

   Affiliation as printed

   University Lyon 1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, 69230, Saint-Genis-Laval, France

7. F. E. Bauer

   Space Science Institute · Pontificia Universidad Católica de Chile · Millennium Institute of Astrophysics

   Affiliation as printed

   Instituto de Astrofísica and Centro de Astroingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile

   Millennium Institute of Astrophysics, Nuncio Monseñor Sótero Sanz 100, Of 104, Providencia, Santiago, Chile

   Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, Colorado 80301, USA

8. L. Guaita

   Universidad Andrés Bello

   Affiliation as printed

   Departamento de Ciencias Fisicas, Universidad Andres Bello, Fernandez Concha 700, Las Condes, Santiago, Chile

9. Alexandre Jeanneau

   Lyon 1 Université · Centre National de la Recherche Scientifique · Centre de Recherche Astrophysique de Lyon

   Affiliation as printed

   University Lyon 1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, 69230, Saint-Genis-Laval, France

10. David J. Lagattuta

    Durham University

    Affiliation as printed

    Centre for Extragalactic Astronomy, Durham University, South Road, Durham DH1 3LE, UK

    Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE, UK

11. Floriane Leclercq

    University of Geneva

    Affiliation as printed

    Observatoire de Genève, Université de Genève, 51 Chemin de Pégase, 1290 Versoix, Switzerland

12. M. V. Maseda Aachen Leiden Observatory

    Leiden University · Leiden Observatory

    Affiliation as printed

    Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands

13. Jorryt Matthee

    ETH Zurich

    Affiliation as printed

    Department of Physics, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich, Switzerland

14. Themiya Nanayakkara Aachen Leiden Observatory

    Leiden University · Leiden Observatory

    Affiliation as printed

    Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands

15. R. Pelló

    Centre National de la Recherche Scientifique · Aix-Marseille Université · Laboratoire d’Astrophysique de Marseille

    Affiliation as printed

    Aix Marseille Université, CNRS, CNES, LAM (Laboratoire d’Astrophysique de Marseille), UMR 7326, 13388 Marseille, France

    Aix Marseille Université, CNRS, CNES, LAM (Laboratoire d'Astrophysique de Marseille), UMR 7326, 13388 Marseille, France

16. Tran Thi Thai

    Centre National de la Recherche Scientifique · Aix-Marseille Université · Laboratoire d’Astrophysique de Marseille · Graduate University of Science and Technology · Trung tâm Vũ trụ Việt Nam · Vietnam Academy of Science and Technology

    Affiliation as printed

    Aix Marseille Université, CNRS, CNES, LAM (Laboratoire d’Astrophysique de Marseille), UMR 7326, 13388 Marseille, France

    Department of Astrophysics, Vietnam National Space Center, VAST, 18 Hoang Quoc Viet, Hanoi, Vietnam

    Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Vietnam

    Aix Marseille Université, CNRS, CNES, LAM (Laboratoire d'Astrophysique de Marseille), UMR 7326, 13388 Marseille, France

17. P. Tuan-Anh

    Graduate University of Science and Technology · Trung tâm Vũ trụ Việt Nam · Vietnam Academy of Science and Technology

    Affiliation as printed

    Department of Astrophysics, Vietnam National Space Center, VAST, 18 Hoang Quoc Viet, Hanoi, Vietnam

    Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Vietnam

18. Anne Verhamme

    University of Geneva

    Affiliation as printed

    Observatoire de Genève, Université de Genève, 51 Chemin de Pégase, 1290 Versoix, Switzerland

19. Eloïse Vitte

    University of Geneva · European Southern Observatory

    Affiliation as printed

    ESO Alonso de Cordova 3107, Vitacura, Santiago, Chile

    Observatoire de Genève, Université de Genève, 51 Chemin de Pégase, 1290 Versoix, Switzerland

20. L. Wisotzki

    Leibniz Institute for Astrophysics Potsdam

    Affiliation as printed

    Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany