Weird Edges during rendering

I’ve modeled the object using polar array and joined them together. After applying tangent shader and rendered it, it has these edges showing at the top of the surface. I have applied smooth and splitedge modifier but to no avail. Any ideas?

Dunno if perhaps you’ve fixed this problem already, but have you checked to make sure you don’t have any internal faces? Specifically be sure that there is no edge running vertically at the center of the object.