Hello Eduard,
I am not an expert, but I believe these are converging crepescular rays. The convergence is a matter of perspective much like railroad tracks converge as the approach our horizon perspective. Here is a quick link I found that I believe describes the phenomena you have imaged. Hope this helps and is accurate.
http://www.ems.psu.edu/~demark/471/CrepuscularRays.html
Jeff
