Ly$\rm α$ halos and UV continuum morphologies of Tadpole Galaxies at $z> 3$

Abstract

Tadpole and clump-chain galaxies are a morphologically distinct population among high-redshift star-forming galaxies whose disturbed structures may influence the escape and propagation of Ly$α$ photons. We investigate the Ly$α$ and UV continuum properties of 12 tadpole galaxies in the redshift range of z $\sim$ 3 -- 5.5 identified in the Hubble Ultra Deep Field (HUDF) using deep MUSE observations. Accounting for their elongated morphologies, we construct surface brightness profiles and characterize the spatial extent of their Ly$α$ emission. Extended Ly$α$ halos are detected in 10 of the 12 galaxies, demonstrating that diffuse Ly$α$ emission is common among tadpole systems. Approximately 40\% of the sample exhibits double-peaked Ly$α$ profiles. While the effective radii ($\rm R_{e}$) of the Ly$\rm α$ emission generally follow the spatial extent of the UV continuum, the Ly$ \rm α$ halos are typically more symmetric and often exhibit spatial offsets from the stellar component. Some galaxies also display asymmetric and outflow-like Ly$\rm α$ structures suggestive of anisotropic escape and complex radiative transfer effects. Together, these results suggest that the disturbed morphologies of tadpole galaxies may influence the transport of Ly$\rm α$ photons and contribute to the formation of extended Ly$\rm α$ halos in the circumgalactic medium.