JWST reveals a highly ionized nebula powered by an ultraluminous X-ray source with a massive black hole in the metal-poor galaxy Holmberg II

F. A. Fogantini, P. Zeidler, L. M. Oskinova +9

Recent James Webb Space Telescope (JWST) observations have revealed fine-structure lines of ions with ionization potentials $\gtrsim 50$\,eV, such as [Ne\,{\sc v}] and [O\,{\sc iv…