Skip to main content

Research Repository

Advanced Search

Connecting Lyα and Ionizing Photon Escape in the Sunburst Arc

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

Connecting Lyα and Ionizing Photon Escape in the Sunburst Arc Thumbnail


Authors

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

Håkon Dahle

Christopher M. Malhas

Brian Welch

Taylor A. Hutchison

Raven Gassis

Suhyeon Choe

Prasanna Adhikari



Abstract

We investigate the Lyα 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 Lyα profile indicating direct Lyα escape. Non-LyC-leaking regions show a redshifted Lyα peak, a redshifted and central Lyα peak, or a triple-peaked Lyα profile. We measure the properties of the Lyα profile from different regions of the galaxy using R ∼ 5000 Magellan/Magellan Echellette spectra. We compare the Lyα spectral properties to LyC and narrowband Lyα maps from Hubble Space Telescope imaging to explore the subgalactic Lyα−LyC connection. We find strong correlations (Pearson correlation coefficient r > 0.6) between the LyC escape fraction (
) and Lyα (1) peak separation vsep, (2) ratio of the minimum flux density between the redshifted and blueshifted Lyα peaks to continuum flux density
, and (3) equivalent width. We favor a complex H i geometry to explain the Lyα profiles from non-LyC-leaking regions and suggest two H i geometries that could diffuse and/or rescatter the central Lyα peak from the LyC-leaking region into our sight line across transverse distances of several hundred parsecs. Our results emphasize the complexity of Lyα 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 Lyα, blueshifted Lyα, and escaping LyC photons in the Sunburst Arc underscore the importance of resolving the physical scales that govern Lyα and LyC escape.

Citation

Owens, M. R., Kim, K. J., Bayliss, M. B., Rivera-Thorsen, T. E., Sharon, K., Rigby, J. R., Navarre, A., Florian, M., Gladders, M. D., Burns, J. G., Khullar, G., Chisholm, J., Mahler, G., Dahle, H., Malhas, C. M., Welch, B., Hutchison, T. A., Gassis, R., Choe, S., & Adhikari, P. (2024). Connecting Lyα and Ionizing Photon Escape in the Sunburst Arc. Astrophysical Journal, 977(2), Article 234. https://doi.org/10.3847/1538-4357/ad9247

Journal Article Type Article
Acceptance Date Nov 10, 2024
Online Publication Date Dec 17, 2024
Publication Date Dec 20, 2024
Deposit Date Jan 22, 2025
Publicly Available Date Jan 22, 2025
Journal The Astrophysical Journal
Print ISSN 0004-637X
Electronic ISSN 1538-4357
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 977
Issue 2
Article Number 234
DOI https://doi.org/10.3847/1538-4357/ad9247
Public URL https://durham-repository.worktribe.com/output/3347012

Files





You might also like



Downloadable Citations