The enigma of Ultra-Luminous X-ray sources and its Achilles Heel in the Foot Nebula
Abstract
We request 15.2 hr science time for the NIRspec IFU and MIRI MRS observations of the template low-metallicity ultra-luminous X-ray source (ULX) Holmberg II X-1 and the high-excitation HeIII nebula it powers. Believed to be comprised of a black hole accreting matter from its massive-star donor, Holmebrg II X-1 is the closest and the best example of the enigmatic population of accreting black hole binaries in low-metallcity galaxies. It is hypothesised that strong hard ionizing radiation and energetic outflows of the accreting black holes is the key feedback agent regulating the state of the interstellar medium in low-metallicity galaxies but lack of conclusive observations precludes definite conclusions. The unique capabilities of JWST allow us to spectroscopically map the nebulae around ULXs. Using both, NIRspec and MIRI, we will chart the ionization fronts within the Holmberg II X-1 nebula, establish whether the dust is present, and finally settle the type of its donor star. Complemented by archival X-ray, UV and optical spectra, the new JWST data will be analyzed using photoionization and dust models to uncover the physical conditions within the nebula and shed much needed light on the nature of ULXs.
- Publication:
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JWST Proposal. Cycle 3
- Pub Date:
- February 2024
- Bibcode:
- 2024jwst.prop.5846O