NICI Filters
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NICI has one filter wheel in each science channel. The current filter complement is listed below, with the location of each filter indicated by the Gemini ID numbers in the "Channel 1" and "Channel 2"columns. Click on an ID number to see the transmission curve for the actual filter element in that channel, if available. Click here to download a .zip file containing all available transmission curve data.
The 1%, 4%, and 5% methane filters are used for Simultaneous Spectral Differential Imaging (SSDI) in the methane bandhead. These filters were built to high precision specifications for optimal image quality. The 1% and 4% filters are mounted in both filter wheels so they can be interchanged to help cancel non-common-path errors between the two science channels.
The H20 Ice L filter was provided by a principal investigator.
The remaining filters are from the same batch as the NIRI filters.
The following table lists the available filters. Entries with a Gemini ID number indicate the installed filters for the individual channels. If the entry is blank, the filter is not installed in that channel.
NICI Filters | |||||
Filter Name | Central Wavelength | Wavelength range or Width | Channel 1 (Red) Gemini ID |
Channel 2 (Blue) Gemini ID |
Note |
Block | -- | -- | -- | -- | |
CH4 H 1% S |
1.587 | 0.0150 (0.94%) | G0724 |
G0722 |
|
CH4 H 1% Sp | 1.603 | 0.0162 (1.01%) | G0728 |
G0726 |
|
CH4 H 1% L | 1.628 | 0.0174 (1.07%) | G0720 |
G0732 |
|
CH4 H 1% L_2 | 1.628 | 0.0174 (1.07%) | G0735 |
||
CH4 H 4% S | 1.578 | 0.062 (4.00%) | G0742 |
G0743 |
|
CH4 H 4% L | 1.652 | 0.066 (3.95%) | G0740 |
G0737 |
|
CH4 K 5% S |
2.080 | 0.105 (5.06%) | G0746 | ||
CH4 K 5% L |
2.241 | 0.107 (4.84%) | G0748 | ||
H20 Ice L |
3.09 | 3.02 - 3.15 | G0715 | ||
J |
1.25 | 1.15-1.33 | G0702 | ||
H | 1.65 | 1.49-1.78 | G0703 | ||
K | 2.20 | 2.03-2.36 | G0704 | ||
Ks | 2.15 | 1.99-2.30 | G0705 | ||
Kprime | 2.12 | 1.95-2.30 | G0706 | ||
Lprime | 3.78 | 3.43-4.13 | G0707 | Must be used w/ H50/50 to reduce bgd. | |
Mprime | 4.68 | 4.55-4.79 | G0708 | Installed, but not available due to saturation. | |
[Fe II] | 1.644 | 1.5% | G0712 | ||
H2 1-0 S(1) | 2.1239 | 1.23% | G0709 | ||
Br-gamma | 2.1686 | 1.36% | G0711 | ||
Kcont | 2.2718 | 1.55% | G0710 | ||
CH4 H 6.5% S | 1.596 | 0.1175 (7.3%) | G0713 | ||
CH4 H 6.5% L | 1.701 | 0.0972 (5.7%) | G0714 |