What do you mean by artifacts?
An artifact is something that shows in the data but is not real, it is a byproduct of the measuring or storage system.
For example you might see ringing on a line, this ringing can be real, that is it is actually in the circuit or it can be caused by the scope lead being applied to the signal pin. If when you use a better scope lead there is no ringing then you conclude that the first observation was an artifact, it was not real.
There are many other ways to get artifacts in your measurement like trouble with grounds. As I said I don't believe those measurements are real.