Ultra-luminous X-Ray Sources in HARO II and the Role of X-Ray Binaries in Feedback in Lyα Emitting Galaxies

Prestwich, A.H.; Jackson, F.; Kaaret, P.; Brorby, M.; Roberts, T.P.; Saar, S.H.; Yukita, M.

Abstract

Lyman Break Analogs (LBAs) are local proxies of high-redshift Lyman Break Galaxies. Spatially resolved studies of nearby starbursts have shown that Lyman continuum and line emission are absorbed by dust and that the Lyα is resonantly scattered by neutral hydrogen. In order to observe Lyα emission from star-forming regions, some source of feedback is required to blow the neutral gas away from the starburst to prevent scattering and allow the Lyα emission to escape. We show that there are two X-ray point sources embedded in the diffuse emission of the LBA galaxy Haro 11. CXOU J003652.4-333316 (abbreviated to Haro 11 X-1) is an extremely luminous (L${}_{{\rm{X}}}\sim {10}^{41}$ erg s−1), spatially compact source with a hard-X-ray spectrum. We suggest that the X-ray emission from Haro 11 X-1 is dominated by a single accretion source. This might be an active galactic nucleus or a source similar to the extreme black hole binary (BHB) M82 X-1. The hard X-ray spectrum indicates that Haro 11 X-1 may be a BHB in a low accretion state. In this case, the very high X-ray luminosity suggests an intermediate mass black hole that could be the seed for formation of a supermassive black hole. Source CXOU J003652.7-33331619.5 (abbreviated Haro 11 X-2) has an X-ray luminosity of ${L}_{{\rm{X}}}\sim 5\times {10}^{40}$ erg s−1 and a soft X-ray spectrum (power-law photon index Γ ~ 2.2). This strongly suggests that Haro 11 X-2 is an X-ray binary in the ultra luminous state (i.e., an Ultra Luminous X-ray source, ULX). Haro 11 X-2 is coincident with the star-forming knot that is the source of the Lyα emission. The association of a ULX with Lyα emission raises the possibility that strong winds from X-ray binaries play an important role in injecting mechanical power into the interstellar medium, thus blowing away neutral material from the starburst region and allowing the Lyα to escape. We suggest that feedback from X-ray binaries may play a significant role in allowing Lyα emission to escape from galaxies in the early universe.

Citation

Prestwich, A., Jackson, F., Kaaret, P., Brorby, M., Roberts, T., Saar, S., & Yukita, M. (2015). Ultra-luminous X-Ray Sources in HARO II and the Role of X-Ray Binaries in Feedback in Lyα Emitting Galaxies. Astrophysical Journal, 812(2), Article 166. https://doi.org/10.1088/0004-637x/812/2/166

• Journal Article Type: Article
• Acceptance Date: Jul 23, 2015
• Publication Date: Oct 20, 2015
• Deposit Date: Oct 26, 2015
• Publicly Available Date: Nov 2, 2015
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 812
• Issue: 2
• Article Number: 166
• DOI: https://doi.org/10.1088/0004-637x/812/2/166
• Keywords: Galaxies: clusters: general, Galaxies: dwarf, Galaxies: starburst, X-rays: binaries, X-rays: galaxies.
• Related Public URLs: http://arxiv.org/abs/1507.07900