Can this bow be self-supporting?

It's hard to see in the photos. Therefore, here are two others attached. A piece of wall is still standing. On one side, there is a chimney shaft. We basically just want to straighten the passage, so from round to square. Of course, I would have to check as soon as I am in the house whether a beam has been incorporated there. As most people here suspect, I hope so, of course :)

One more time over the walls and underneath

Another possibility: it looks like a semi-detached house. If that's the case, you might want to ask the neighbors. Our 1960s semi-detached house was built identically to its twin, and at some points interesting for our renovation, the neighbors had already been active and knew more.

Edit: and both for them and for us, the building plans back then were probably more of a rough guideline for inspiration - so don’t rely on them ;)

So, I have now received the structural plans. It is a load-bearing wall. My first action when I have access to the house will be to check by tapping the plaster whether a lintel has been installed. Could it also be that a concrete lintel is installed over this length? Can I also detect a lintel, for example with a Bosch detection device?

Jesus - now I first read:

"Can this bow be a transgender"

O tempora, o mores!

*duck and away*

How thick is the wall? How wide is the opening? I want to bet that there is no beam inside. Take the hammer drill and bore a hole 10 cm below the ceiling. There you will see if it is masonry.