I'm far from expert, so wait and see what other answers you get, I think this is what is commonly called wild carrot.
I think it is Phacelia. An annual usually grown as green manure and dug in when still green.
Not carrot. They look much more like Phacelia - as you say, often grown as a green manure, also as a plant for bees as they love the flowers.
You could dig them in and then prepare to turf/sow grass seed, or dig them up and use them on the compost heap.