The Instrument

Michelle is a mid-infrared imager/spectrometer, which was built at the ATC in Edinburgh, Scotland. It uses an SBRC Si:As 320×240-pixel array and operates between 8 and 25 microns. Michelle offers several modes of observing, which include:

  • Imaging (67.2 x 50.4 arcsec field of view at 0.21 arcsecs per pixel)
  • Imaging polarimetry
  • Spectroscopy (R=200 to 30000, a ~91 arcsec long slit, 0.38 arcsec per pixel)
  • Spectropolarimetry

Spectroscopy Mode:

Michelle contains five gratings offering a wide selection of resolutions and wavelengths. Any grating can be selected in a couple of minutes, so observers are not limited to one or two gratings per run. Each can be used with different slits, 1, 2, 3, 4, and 8-pixels (0″.38, 0″.76, etc.) wide, all of which are approximately 91 arcseconds long. Resolving powers range from 200 to 30,000.

Imaging Mode:

Eleven filters are available, broad and narrow, and cover the wavelength range from 8 to 25 microns. Available filters, including passbands, can be found in the Michelle planning applet.