It seems fairly certain there is a large black hole, about 25,000 ly from Earth roughly in the center of our galaxy, in the direction of the Sag. A radio source.
• In fact, is it thought to be literally at the center of gravity of our galaxy?
Does we know, or is this uncertain?
• Indeed, do we actually know where the CG of the galaxy is?
I observe that the term "Galactic Center" seems to be an astronomical term. (Example.) Can an astronomer tell me: does that term mean what we believe to be the CG, or rather, is it a nominal mapping point?
• If the black hole IS exactly at the CG of the galaxy ... why?
It would seem to me a big BH could form any old place, and perhaps still be orbiting or oscillating the CG - right? If the SBH is literally the CG of there galaxy, is there a reason for that? (Like, "SBH can only form at the CG" .. or "stellar collisions can only happen at the CG" .. or whatever, those are only wild guesses.)
Or indeed, is the SBH the "main player" in the galaxy - just as the solar system formed around the sun (so it would be silly to ask "why is the sun at the center"), did the SBH sort of co-form with the galaxy (or something?)
In any event, is the SBH at the actual CG of our galaxy? Do we know?