There is always the chance of there being a random stream of smoke or haze that gets caught in front of the camera, and that can never be ruled out.
However, knowing the Kirlean photography (photograpy of the spirit world and of unseen magnetic fields) is done on a regular basis, it's quite possible that you did photograph some unseen or etheric energy field.
Based on the photograph, it's hard to tell either way. Normally, Kirlean photography must be done with special equipment and under a controlled environment, but under a very powerful manifestation, it could occur in a normal camera setting.
Whatever caused it, it's a fascinating effect, and should not be a source of fear for you.
