Resolving the ultraluminous X-ray sources in the Lyα emitting galaxy Haro 11

Lyman continuum and line emission are thought to be important agents in the reionization of the early Universe. Haro 11 is a rare example of a local galaxy in which Ly alpha and continuum emission have escaped without being absorbed or scattered by ambient gas and dust, potentially as a consequence of feedback from its X-ray sources. We build on our previous Chandra analysis of Haro 11 by analysing three new observations. Our subpixel spatial analysis reveals that the two previously known X-ray sources are each better modelled as ensembles of at least two unresolved point sources. The spatial variability of these components reveals X1 as a dynamical system where one luminous X-ray source (L-X similar to 10(41) erg s(-1)) fades as a secondary source begins to flare. These might be intermediate-mass black holes or low-luminosity active galactic nuclei (AGNs) near the centre of the galaxy in the process of merging. Optical emission line diagnostics drawn from the literature suggest that while the galaxy as a whole is consistent with starburst signatures of ionization, the individual regions wherein the X-ray sources reside are more consistent with AGN/composite classification. The sources in X2 exhibit some degree of flux variability. X2a dominates the flux of this region during most observations (L-X similar to 6x10(40) erg s(-1)), and gives the only evidence in the galaxy of a soft ultraluminous X-ray source capable of high-energy winds, which we suggest are responsible for allowing the coincident Ly alpha emission to escape.

Automated summary

Lyman continuum and line emission play important roles in the reionization of the early Universe. Haro 11 is a local galaxy where Ly alpha and continuum emission can escape without being absorbed, potentially due to feedback from X-ray sources. Spatial analysis reveals dynamic variability and flux changes in X1 and X2 sources.