Specific questions for black body proponents:

Why is there a layer of penumbral filaments that shine? What are these made of? Why do these filaments shine visible light only in this layer, not above it, and not below it? Why is there an end to the penumbral filaments, and why is there an UMBRA that does not shine along the sides of the sunspot? What is underneath the umbra that is not shining? What is the umbra made of?