Rapid turn-on of a luminous X-ray source in the candidate Lyman continuum emitting galaxy Tol 0440-381

TL;DR

This study reports a rapid increase in X-ray brightness in the galaxy Tol 0440-381, suggesting the presence of an accretion-powered source that may facilitate Lyman continuum photon escape.

Contribution

It provides the first detailed X-ray observation of a candidate LyC emitter showing rapid variability, linking X-ray properties to LyC escape mechanisms.

Findings

X-ray source brightened by at least a factor of 4 over 3.8 days.

X-ray luminosity reached 1.6×10^40 erg/s.

Similar X-ray properties found in other LyC-emitting galaxies.

Abstract

Chandra observations of the nearby, candidate Lyman-continuum (LyC) emitting galaxy Tol 0440-381 show brightening of an X-ray source by at least a factor of 4 to a luminosity of 1.6E40 erg/s over 3.8~days. The X-ray emission likely arises from either a low-luminosity AGN or an ultraluminous X-ray source. The properties of the X-ray source are similar to those found in Haro 11 and Tololo 1247-232, the only other LyC-emitting galaxies that have been resolved in X-rays. All three galaxies host luminous, variable, and hard spectrum X-ray sources that are likely accretion-powered. Accretion onto compact objects produces powerful outflows and ionizing radiation that could help enable LyC escape.