Lyman Continuum Leakers at $z>3$ in the GOODS-S Field: Starburst or Not?

TL;DR

This study analyzes 23 high-redshift LyC leakers to understand their star-forming properties, revealing that LyC photon escape does not solely depend on starburst activity and is associated with diverse star formation rates.

Contribution

The paper provides a systematic analysis of LyC leakers at z > 3 using combined HST and JWST data, highlighting their diverse star formation characteristics and challenging the notion that only starbursts leak LyC photons.

Findings

LyC leakers have blue UV slopes indicating high escape fractions.

They exhibit a wide range of specific star formation rates.

Not all LyC leakers are starburst galaxies, some lie on the main sequence.

Abstract

We investigate the star-forming properties of 23 Lyman Continuum (LyC) leakers at z > 3 in the Great Observatories' Deep Survey-South (GOODS-S) field based on a systematic review of LyC observations from the literature. Using data from the Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST), we construct the spectral energy distributions (SEDs) for these LyC leakers, covering the spectrum from rest-frame ultraviolet to near-infrared. Through the application of a unified modeling approach, we measure the ultraviolet slope, star formation rate, and stellar mass for these LyC leakers in a consistent manner. These high-redshift LyC leakers demonstrate statistically blue UV-continuum slopes, which is consistent with their high escape fraction of LyC photons. We find that these high-redshift LyC leakers span a wide range of specific star formation rate (log(sSFR/yr) from -8.6 to -6.7). Ten of these LyC leakers are located on the star formation main sequence, instead of all being in the starburst mode. The results indicate that intense bursts of star formation are not necessarily required for the leakage of LyC photons for galaxies at z > 3.