WIYN / Bench Spectrograph

Measured Spectrograph Input Beam Profile:

This postscript plot comares the measured output irradiance patterrns for the 4 WIYN cables: MOS red and blue, DensePak, and SparsePak, as listed below. The "reference cable" is also from Bershady et al. 2003, and represents a carefully prepared, spooled, glued, and polished single fiber residing in a laboratory. The "full beam" is a fully-illuminated f/6.3 beam. The "WIYN beam" is the obstructed f/6.3 beam input to the fibers (obstructions from the secondary and central hole in the primary that removes all light slower than f/15.2 -- see the WIYN Simulator.)

• Red MOS data
• Blue MOS data
• DensePak data

  Format:   f/, EE
  Source:   Smith & Conselice (1999, unpublished)
  Notes:   These data were taken with cables on the telecope. Some details of the measurements can be found here, but some comments made in the Conselice report are confusing and unclear. For example, just how much light has been lost by the baffling in the foot, and whether this was properly corrected is not well known.

• SparsePak data

  Format:   f/, EE, dEE
  Source:   Bershady et al. 2003, in preparation for PASP, "SparsePak: A Formatted Fiber Field Unit for the WIYN Telescope Bench Spectrograph. I. Design, Construction, and Calibration"
  Notes:   These data are laboratory measurements, well-documented in above paper. There is no vignetting from the fiber toes, and fiber illumination and band-pass were well controlled.