A Local Clue to the Reionization of the Universe

TL;DR

This paper identifies a local galaxy analog with a high ionizing photon escape fraction, providing insights into the reionization era and validating an indirect detection technique crucial for high-redshift studies.

Contribution

The study presents a local galaxy analog with a 21% escape fraction of ionizing flux, confirming the presence of neutral gas gaps and validating an indirect detection method for reionization research.

Findings

Detected a local galaxy with 21% ionizing flux escape fraction.

Confirmed gaps in neutral gas due to strong winds and radiation.

Validated the use of residual flux in absorption lines as an indirect detection method.

Abstract

Identifying the population of galaxies that was responsible for the reionization of the universe is a long-standing quest in astronomy. We present a possible local analog that has an escape fraction of ionizing flux of 21%. Our detection confirms the existence of gaps in the neutral gas enveloping the starburst region. The candidate contains a massive yet highly compact star-forming region. The gaps are most likely created by the unusually strong winds and intense ionizing radiation produced by this extreme object. Our study also validates the indirect technique of using the residual flux in saturated low-ionization interstellar absorption-lines for identifying such leaky galaxies. Since direct detection of ionizing flux is impossible at the epoch of reionization, this is a highly valuable technique for future studies.