Part of the difficulty is a process called photoionization, in which the high - energy photons conveying the x-rays strip away electrons from atoms within the accretion disk. (sciencemag.org)
Interacting supernovae from photoionization - confined shells around red supergiant stars. (nature.com)
The number of observables... ▽ More We present a detailed photoionization model of G29.96 - 0.02 (hereafter G29.96), one of the brightest Galactic Ultra Compact HII (UCHII) regions in the Galaxy. (arxiv.org)