Resolving Microlens Blends Using Image Subtraction

Blended light is an important source of degeneracy in the characterization of microlensing events, particularly in binary-lens and high-magnification events. We show how the techniques of image subtraction can be applied to form an image of the blend with the source removed. In many cases, it should be possible to construct images with a very high signal-to-noise ratio. Analysis of these images can help distinguish between competing models that have different blend fractions, and in some cases should allow direct detection of the lens.