Honoring Nod-and-Shuffle

R. S. Fisher, K. Roth

May 28, 2008

The creators of an innovative observing technique called “Nod and Shuffle” will be honored with The Maria and Eric Muhlmann award at the Astronomical Society of the Pacific meeting in St. Louis this week. Karl Glazebrook (Swinburne University of Technology), Joss Bland-Hawthorn (University of Sydney), and Jean-Claude Cuillandre (Canada France Hawaii Telescope) are receiving the award for “… recent significant observational results made possible by innovative advances in astronomical instrumentation, software, or observational infrastructure…”

The nod-and-shuffle technique, also know as ‘Va-et-Vient’ in French, was first demonstrated on the ESO NTT telescope. It was then implemented by Drs. Glazebrook and Bland-Hawthorn in 2001 at the Anglo-Australian Observatory. The great advantage of the “Nod and Shuffle” technique is that it lets an observer achieve extremely accurate sky subtraction during optical spectroscopic observations. This is done by quickly nodding the telescope between a target and nearby sky position while simultaneously shuffling the charges within the detector itself. Increases in sky-subtraction accuracy of a factor of ten are routinely obtained using nod-and-shuffle with modern facility-class instruments.

While nod-and-shuffle was first implemented at other observatories, the technique has found its greatest success at Gemini. The scientific motivation for implementing nod-and-shuffle at Gemini was the Gemini Deep Deep Survey, originally proposed to the Gemini director Matt Mountain in January 2002 by proposal PIs Roberto Abraham, Patrick McCarthy, and Karl Glazebrook. Both GMOS North and South are fully nod-and-shuffle ready and the technique is often used in the queue. The technique is particularly good for moderately low resolution spectroscopy of very faint targets in the red end of the optical wavelength regime, in either long-slit or multi-object spectroscopy mode. Examples of science results produced using nod-and-shuffle with GMOS are available at the following links:

The GDDS Opens a New Window Into the Distant Universe of Galaxy Assembly http://www.gemini.edu/index.php?option=content&task=view&id=18

Most Distant Quasar Samples Conditions in the Young Universe http://www.gemini.edu/index.php?option=content&task=view&id=254

Congratulations to Drs. Glazebrook, Bland-Hawthorn, and Cuillandre for receiving this award!