I live in Alexandria VA. Took these photos today. This grass started as a small clump that I noticed a couple years ago because it looked very fine and attractive

mixed in with all the random crap in my yard. It has spread, it's a rare thing that something I actually like has spread. It started in a part-sun area and has spread to sunny areas. What's really weird is it seems to be taking over from the nasty Bermuda grass that I despise. It's a very low growing grass and didn't start to brown a little until just the last few weeks. I've read about all the likely choices and the only one I think may be close would be perennial rye??

Thanks for help