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J1316+2614 at z=3. 613 is the UV-brightest (Mₔₕ = -24. 7) and strongest Lyman continuum (LyC, f₄ₒ₂^LyC 90%) emitting star-forming galaxy known, showing also signatures of inflowing gas from its blue-dominated Ly profile. Here, we present high-resolution imaging with the HST and VLT of the LyC, Ly, rest-UV, and optical emission of J1316+2614. Detailed analysis of the LyC and UV light distributions reveals compact yet resolved profiles, with LyC and UV morphologies showing identical half-light radii of 220 pc. The continuum-subtracted Ly emission reveals an extended filamentary structure of 6. 0 kpc oriented south-north with only weak/residual flux within the stellar core, suggesting a Ly "hole". J1316+2614 presents remarkably high SFR and stellar mass surface densities of log (ₒ₅ₑ M_/yr/kpc²) = 3. 470. 11 and log (₌ M_/pc²) = 4. 200. 06, respectively, which are among the highest observed in star-forming galaxies. Our findings indicate that J1316+2614 is a powerful, young, and compact starburst, leaking significant LyC photons due to the lack of gas and dust within the starburst. We explore the conditions for gas expulsion using a simple energetic balance and find that, given the strong binding force in J1316+2614, a high star formation efficiency (ₒ₅ 0. 7) is necessary to remove the gas and explain its exposed nature. Our results thus suggest a close link between high ₒ₅ and high f₄ₒ₂^LyC. This high efficiency can also naturally explain the remarkably high SFR, UV-luminosity, and efficient mass growth of J1316+2614, where at least 62% of its mass formed in the last 6 Myr. J1316+2614 may exemplify an intense, feedback-free starburst with a high ₒ₅, similar to those proposed for UV-bright galaxies at high redshifts. (ABRIDGED)
Marques-Chaves et al. (Fri,) studied this question.