Disentangling the X-ray variability in the Lyman continuum emitter Haro 11

TL;DR

This study investigates X-ray variability and absorption in the local Lyman break analog Haro 11, revealing that lower absorption in a LyC-leaking source suggests superwinds may facilitate ionizing radiation escape.

Contribution

It provides the first detailed spectral and variability analysis of Haro 11's X-ray sources, linking lower absorption to LyC leakage and superwind activity.

Findings

X2 has lower absorption and higher LyC leakage.

X-ray variability linked to ionized superwinds.

Superwinds may create channels for LyC escape.

Abstract

Lyman break analogs in the local Universe serve as counterparts to Lyman break galaxies (LBGs) at high redshifts, which are widely regarded as major contributors to cosmic reionization in the early stages of the Universe. We studied XMM-Newton and Chandra observations of the nearby LBG analog Haro 11, which contains two X-ray-bright sources, X1 and X2. Both sources exhibit Lyman continuum (LyC) leakage, particularly X2. We analyzed the X-ray variability using principal component analysis (PCA) and performed spectral modeling of the X1 and X2 observations made with the Chandra ACIS-S instrument. The PCA component, which contributes to the X-ray variability, is apparently associated with variable emission features, likely from ionized superwinds. Our spectral analysis of the Chandra data indicates that the fainter X-ray source, X2 (X-ray luminosity $L_{\rm X} \sim 4 \times 10^{40} $ erg s$^{-1}$), the one with higher LyC leakage, has a much lower absorbing column ($N_{\rm H} \sim 1.2 \times 10^{21}$ cm$^{-2}$) than the heavily absorbed luminous source X1 ($L_{\rm X} \sim 9 \times 10^{40} $ erg s$^{-1}$ and $N_{\rm H} \sim 11.5 \times 10^{21}$ cm$^{-2}$). We conclude that X2 is likely less covered by absorbing material, which may be a result of powerful superwinds clearing galactic channels and facilitating the escape of LyC radiation. Much deeper X-ray observations are required to validate the presence of potential superwinds and determine their implications for the LyC escape.