Michelle Slits

Michelle's slit mask currently contains five slits for spectroscopy as well as an "open" mask for imaging. Resolving power is inversely proportional to slit width. The width of the two-pixel wide slit (~0.4") somewhat exceeds the diffraction limit in the 10um window (1.2 lambda/D at Gemini corresponds to 0.3" at 10.0um), and is narrower than the diffraction limit in the 20um window. The three-pixel wide slit is a better match at 20um. Our best estimate of the imaging pixel scale is 0.1005 arc-seconds per pixel, based upon binary star separation measurements. In spectroscopy mode the angular size of pixels projected on the sky is twice that for imaging.

Last update February 23 2006; K. Volk, R. S. Fisher & T. R. Geballe