The first image I get on Yandex is "Professor G.K. Egan" on the "staff-fake.html" page of a University website[0]. Aside from the "fake" part of the URL, it's not "the" Greg Egan we're talking about.
The second image is his profile picture on X/Twitter[1], which one can assume is fake since he says himself that his only puts fake photos (and that picture seems to be nowhere else on the Internet).
The third image is a speaker on the French-speaking Belgian radio that has one episode of his show about Greg Egan[2].
The fourth image is Knuth Berger, a journalist that has a discussion with Tim Egan about a book[3].