Resolving the ultraluminous X-ray sources in the Ly α emitting galaxy Haro 11
Abstract
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 α 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 (LX ~ 1041 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 (LX ~ 6 × 1040 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 α emission to escape.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2021
- DOI:
- 10.1093/mnras/stab1331
- arXiv:
- arXiv:2105.03504
- Bibcode:
- 2021MNRAS.505..610G
- Keywords:
-
- galaxies: clusters: general;
- galaxies: dwarf;
- galaxies: starburst;
- X-rays: binaries;
- X-rays: galaxies;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 18 pages, 12 figures, Accepted for publication in MNRAS