Thank you for your response. Indeed there is a big gap, in terms of mass, between radiation and atoms to interpret gas winds as "radiation", even for a black hole. Probably, as the term suggests, it is something equivalent to solar wind.
As for your comment on out galaxy as being just a particle of greater scale system, for sure I suppose that even a galaxy will either move in a circular orbit around a bigger object or in a figure-8 orbit towards an even more massive object. As we observe nearby galaxies tend towards a point, then a figure-8 orbit towards the Great Attractor is more likely. Or we could be the "atoms" of another massive object.

Two more questions a bit irrelevant to the current article if you can answer them here or in a later article:

• If I am not mistaken, neutrinos are heavier particles than photons. If this is true, then why neutrinos pass through the earth, but photons don't and most of them are actually reflected?

• (That's a bigger one) About the relation of a bigger object and its smaller containing particles, like earth and atoms. We can view matter as a result of a dense area of smaller "invisible" particles, so this dense area is observed as a single object. For example, earth is a big dense area of atoms and we observe it as a single object relative to its "empty" surroundings. However, atoms, on a lower scale, are also tiny regular systems (like solar systems or galaxies). How could these small solar systems orbit inside and stay around the center of mass? What could be the motion-forces-relations of these inner systems? (Note: mainstream physics says that atoms move randomly inside, however we do not see many random orbits/motion in bigger scale systems)

Thanks in advance.