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Order-Sorting and Acquisition Filters

Home » Sciops » Instruments » GNIRS » Long-Slit, XD & IFU Spectroscopy

The current filter complement for the instrument is listed below. As of 2005B, GNIRS has a new XD filter with overall higher sensitivity and much higher blue sensitivity, and 2 new narrowband filters for acquisition (see below).


Spectroscopy Filters (orders-sorting or broadband)
Filter Name Diffraction order Wavelength range Filter curve Gemini ID
M 1 4.4 - 6.0um yes G0501
L 2 2.90 - 4.25um -G0502
K* 3 1.92 - 2.54um yesG0503
H* 4 1.47 - 1.80um yesG0504
J* 5 1.17 - 1.37um yesG0505
X 6 1.03 - 1.17um yesG0506
XD** cross-disp 0.9 - 2.5um yesG0507

* The sorting filters for orders 3, 4, and 5 are only roughly equivalent to broadband K, H, and J filters, respectively. The long wavelength cut-off of sorter 3 is significantly longer than for standard K filters; as a result, the sensitivity for target acquisition will be worse due to increased background.

** Filter curve shown is for the original XD filter, replaced in 2005B with a slightly broader and more blue-sensitive filter.
Acquisition Filters (narrow band)
Filter Name Width Central Wavelength Filter curve Gemini ID
1.5% 2.122um - G0521
PAH 1.5% 3.295um - G0523

Acquisition filters are defined in acquisition observation sequences. See the OT Details and Acquisition pages for more information.


Last update December 2005, Bernadette Rodgers
Original form, B. Rodgers and Sybil Adams