Connecting Lyα and Ionizing Photon Escape in the Sunburst Arc

M. Riley Owens; Keunho J. Kim; Matthew B. Bayliss; T. Emil Rivera-Thorsen; Keren Sharon; Jane R. Rigby; Alexander Navarre; Michael Florian; Michael D. Gladders; Jessica G. Burns; Gourav Khullar; John Chisholm; Guillaume Mahler; Håkon Dahle; Christopher M. Malhas; Brian Welch; Taylor A. Hutchison; Raven Gassis; Suhyeon Choe; Prasanna Adhikari; Sloan Giant Arcs Survey

doi:10.3847/1538-4357/ad9247

The Astrophysical Journal (Jan 2024)

Connecting Lyα and Ionizing Photon Escape in the Sunburst Arc

M. Riley Owens,
Keunho J. Kim,
Matthew B. Bayliss,
T. Emil Rivera-Thorsen,
Keren Sharon,
Jane R. Rigby,
Alexander Navarre,
Michael Florian,
Michael D. Gladders,
Jessica G. Burns,
Gourav Khullar,
John Chisholm,
Guillaume Mahler,
Håkon Dahle,
Christopher M. Malhas,
Brian Welch,
Taylor A. Hutchison,
Raven Gassis,
Suhyeon Choe,
Prasanna Adhikari,
Sloan Giant Arcs Survey

Affiliations

M. Riley Owens: ORCiD; Department of Physics, University of Cincinnati , Cincinnati, OH 45221, USA ; [email protected]
Keunho J. Kim: ORCiD; Department of Physics, University of Cincinnati , Cincinnati, OH 45221, USA ; [email protected]; IPAC, California Institute of Technology , Pasadena, CA 91125, USA
Matthew B. Bayliss: ORCiD; Department of Physics, University of Cincinnati , Cincinnati, OH 45221, USA ; [email protected]
T. Emil Rivera-Thorsen: ORCiD; The Oskar Klein Centre, Department of Astronomy, Stockholm University , AlbaNova, SE-10691 Stockholm, Sweden
Keren Sharon: ORCiD; Department of Astronomy, University of Michigan , 1085 S. University Avenue, Ann Arbor, MI 48109, USA
Jane R. Rigby: ORCiD; Astrophysics Science Division, NASA Goddard Space Flight Center , 8800 Greenbelt Road, Greenbelt, MD 20771, USA
Alexander Navarre: ORCiD; Department of Physics, University of Cincinnati , Cincinnati, OH 45221, USA ; [email protected]
Michael Florian: ORCiD; Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721, USA
Michael D. Gladders: ORCiD; Department of Astronomy & Astrophysics, The University of Chicago , 5640 S. Ellis Avenue, Chicago, IL 60637, USA; Kavli Institute for Cosmological Physics, University of Chicago , Chicago, IL 60637, USA
Jessica G. Burns: ORCiD; Department of Physics, University of Cincinnati , Cincinnati, OH 45221, USA ; [email protected]
Gourav Khullar: ORCiD; Department of Physics & Astronomy and PITT PACC, University of Pittsburgh , Pittsburgh, PA 15260, USA
John Chisholm: ORCiD; Department of Astronomy, The University of Texas at Austin , 2515 Speedway, Stop C1400, Austin, TX 78712, USA
Guillaume Mahler: ORCiD; Institute for Computational Cosmology, Durham University , South Road, Durham, DH1 3LE, UK; Centre for Extragalactic Astronomy, Durham University , South Road, Durham, DH1 3LE, UK
Håkon Dahle: ORCiD; Institute of Theoretical Astrophysics, University of Oslo , P.O. Box 1029, Blindern, NO-0315 Oslo, Norway
Christopher M. Malhas: ORCiD; Department of Astronomy, The University of Texas at Austin , 2515 Speedway, Stop C1400, Austin, TX 78712, USA
Brian Welch: ORCiD; Astrophysics Science Division, NASA Goddard Space Flight Center , 8800 Greenbelt Road, Greenbelt, MD 20771, USA; Department of Astronomy, University of Maryland , College Park, MD 20742, USA; Center for Research and Exploration in Space Science and Technology, NASA Goddard Space Flight Center , 8800 Greenbelt Road, Greenbelt, MD 20771, USA
Taylor A. Hutchison: ORCiD; Astrophysics Science Division, NASA Goddard Space Flight Center , 8800 Greenbelt Road, Greenbelt, MD 20771, USA
Raven Gassis: ORCiD; Department of Physics, University of Cincinnati , Cincinnati, OH 45221, USA ; [email protected]
Suhyeon Choe: ORCiD; The Oskar Klein Centre, Department of Astronomy, Stockholm University , AlbaNova, SE-10691 Stockholm, Sweden
Prasanna Adhikari: ORCiD; Department of Physics, University of Cincinnati , Cincinnati, OH 45221, USA ; [email protected]
Sloan Giant Arcs Survey

DOI: https://doi.org/10.3847/1538-4357/ad9247
Journal volume & issue: Vol. 977, no. 2
p. 234

Abstract

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We investigate the Ly α and Lyman continuum (LyC) properties of the Sunburst Arc, a z = 2.37 gravitationally lensed galaxy with a multiply imaged, compact region leaking LyC and a triple-peaked Ly α profile indicating direct Ly α escape. Non-LyC-leaking regions show a redshifted Ly α peak, a redshifted and central Ly α peak, or a triple-peaked Ly α profile. We measure the properties of the Ly α profile from different regions of the galaxy using R ∼ 5000 Magellan/Magellan Echellette spectra. We compare the Ly α spectral properties to LyC and narrowband Ly α maps from Hubble Space Telescope imaging to explore the subgalactic Ly α −LyC connection. We find strong correlations (Pearson correlation coefficient r > 0.6) between the LyC escape fraction ( ${f}_{\mathrm{esc}}^{\mathrm{LyC}}$ ) and Ly α (1) peak separation v _sep , (2) ratio of the minimum flux density between the redshifted and blueshifted Ly α peaks to continuum flux density ${f}_{\min }/{f}_{\mathrm{cont}}$ , and (3) equivalent width. We favor a complex H i geometry to explain the Ly α profiles from non-LyC-leaking regions and suggest two H i geometries that could diffuse and/or rescatter the central Ly α peak from the LyC-leaking region into our sight line across transverse distances of several hundred parsecs. Our results emphasize the complexity of Ly α radiative transfer and its sensitivity to the anisotropies of H i gas on subgalactic scales. Large differences in the physical scales on which we observe spatially variable direct-escape Ly α , blueshifted Ly α , and escaping LyC photons in the Sunburst Arc underscore the importance of resolving the physical scales that govern Ly α and LyC escape.

Published in The Astrophysical Journal

ISSN: 1538-4357 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/0004-637X

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