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GNIRS Filters

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	yes	G0503
H*	4	1.47 - 1.80um	yes	G0504
J*	5	1.17 - 1.37um	yes	G0505
X	6	1.03 - 1.17um	yes	G0506
XD**	cross-disp	0.9 - 2.5um	yes	G0507

* 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) [NEW in 2005B]
Filter Name	Width	Central Wavelength	Filter curve	Gemini ID
H_2	1.5%	2.122um	-	G0521
PAH	1.5%	3.295um	-	G0523

Acquisition filters are defined in acquisition observation sequences.
See OT help and Observing Strategies for more information.

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