Lyman continuum escaping from in situ formed stars in a tidal bridge at <i>z</i> = 3
We present an analysis of archival JWST NIRSpec IFS and HST imaging observations of the z = 3 Lyman continuum emitter (LCE) candidate LACES104037. We show that a nearby galaxy, denoted LACES104037-S, has a redshift offset from the main galaxy by only ∼ 450 km s −1 . Together with the identification of a tidal bridge between the galaxies, this indicates that the galaxies are interacting and most likely in the early stages of a merger. We show that the rest-frame LCE cluster sits ∼ 2.7 kpc from the galaxy core in the tidal bridge. It is faint in the nonionizing stellar continuum and shows faint but nonnegligible H α and [O III ] emission, suggesting that much of the gas surrounding the LCE cluster has been dispersed by feedback in the shallower gravitational potential of the tidal bridge. Comparing the direct LyC escape and the local H α emission, we find a total ionizing escape fraction of f esc LyC =57 ± 8% from the LCE cluster. We estimate the age of the LCE cluster to ≲ 6.5 Myr, indicating that the cluster must have formed in situ in the tidal bridge well after the time of closest interaction. LyC escape from tidal stripping or in situ formed stars in tidal features would depend less on intrinsic galaxy properties than typically observed in low- z LCE surveys and could help explain the higher cosmic escape fraction and enhanced diversity of LCE galaxy properties observed at cosmic noon.
Authors
- Sophia R. Flury (ORCID: https://orcid.org/0000-0002-0159-2613)
- Keunho Kim (ORCID: https://orcid.org/0000-0001-6505-0293)
- Håkon Dahle (ORCID: https://orcid.org/0000-0003-2200-5606)
- Alberto Saldana-Lopez (ORCID: https://orcid.org/0000-0001-8419-3062)
- Jens Melinder (ORCID: https://orcid.org/0000-0003-0470-8754)
- Keren Sharon
- S. C. Choe
- M. R. Owens
- M. J. Hayes
- T. E. Rivera-Thorsen
- B. Welch
- E. Solhaug
- J. R. Rigby
- A. Le Reste
Institutions
- California Institute of Technology (US)
- University of Minnesota (US)
- Goddard Space Flight Center (US)
- University of Oslo (NO)
- University of Michigan (US)
- University of Chicago (US)
- Kavli Institute for Particle Astrophysics and Cosmology (US)
- Royal Observatory (GB)
- Institute of Theoretical Physics (CN)
- AlbaNova (SE)
- Infrared Processing and Analysis Center (US)
- International Space Science Institute (CH)
- University of California, Berkeley (US)
- University of Edinburgh (GB)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2026-02-17
- DOI
- https://doi.org/10.1051/0004-6361/202558750
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Aeronautics and Space Administration
- Space Telescope Science Institute
- Vetenskapsrådet