2025/01/14 by Sara Mascia, Mascia, S., L. Pentericci +59 · 2 citations
Physics and Astronomy · #Gamma-ray bursts and supernovae #Astronomy and Astrophysical Research #Cosmology and Gravitation Theories
paper · pdf · doi:10.48550/arxiv.2501.08268
Compact, star-forming galaxies with high star formation rate surface densities (ΣSFR) are often efficient Lyman continuum (LyC) emitters at z≤ 4.5, likely as intense stellar feedback creates low-density channels that allow photons to escape. Irregular or disturbed morphologies, such as those resulting from mergers, can also facilitate LyC escape by creating anisotropic gas distributions. We investigate the influence of galaxy morphology on LyC production and escape at redshifts 5 ≤ z ≤ 7 using observations from various James Webb Space Telescope (JWST) surveys. Our sample consists of 436 sources, which are predominantly low-mass (∼ 108.15 M_\odot), star-forming galaxies with ionizing photon efficiency (ξ\rm ion) values consistent with canonical expectations. Since direct measurements of f\rm esc are not possible during the Epoch of Reionization (EoR), we predict f\rm esc for high-redshift galaxies by applying survival analysis to a subsample of LyC emitters from the Low-Redshift Lyman Continuum Survey (LzLCS), selected to be direct analogs of reionization-era galaxies. We find that these galaxies exhibit on average modest predicted escape fractions (∼ 0.04). Additionally, we assess the correlation between morphological features and LyC emission. Our findings indicate that neither ξ\rm ion nor the predicted f\rm esc values show a significant correlation with the presence of merger signatures. This suggests that in low-mass galaxies at z ≥ 5, strong morphological disturbances are not the primary mechanism driving LyC emission and leakage. Instead, compactness and star formation activity likely play a more pivotal role in regulating LyC escape.