MUSE Illuminates Channels for Lyman Continuum Escape in the Halo of SBS 0335-52E

TL;DR

This study uses MUSE observations to discover ionised gas filaments in the halo of SBS 0335-052E, revealing potential channels for Lyman continuum escape driven by starburst feedback in a metal-poor galaxy.

Contribution

First detection of ionised gas filaments in the halo of SBS 0335-052E, linking starburst feedback to potential Lyman continuum escape channels.

Findings

Ionised filaments extend over 9 kpc from the galaxy.

Filaments are connected to kinematic disturbances caused by a super-shell.

Extended nebular HeII emission indicates locally enhanced UV radiation.

Abstract

We report on the discovery of ionised gas filaments in the circum-galactic halo of the extremely metal-poor compact starburst SBS 0335-052E in a 1.5h integration with the MUSE integral-field spectrograph. We detect these features in H${\alpha}$ and [OIII] emission down to surface-brightness levels of $5 \times 10^{-19}$erg s$^{-1}$cm$^{-2}$arcsec$^{-2}$. The filaments have projected diameters of 2.1 kpc and extend more than 9 kpc to the north and north-west from the main stellar body. We also detect extended nebular HeII $\lambda$4686 emission that brightens towards the north-west at the rim of a star-burst driven super-shell, suggestive of a locally enhanced UV radiation field due to shocks. We also present a velocity field of the ionised gas. The filaments appear to connect seamlessly in velocity space to the kinematical disturbances caused by the shell. Similar to high-$z$ star-forming galaxies, the ionised gas in this galaxy is dispersion dominated. We argue that the filaments were created via feedback from the starburst and that these ionised structures in the halo may act as escape channels for Lyman continuum radiation in this gas-rich system.