FLAMINGOS-2 contains Y, J, H, and K_s filters for imaging and spectroscopy. FLAMINGOS-2 also contains three additional custom filters for spectroscopy: a JH and an HK filter, for use with the JH and HK R~1300 grisms, and a custom "J-low" filter, which has a centroid wavelength of 1.217 µm and is meant to be used with the R3K (R ~ 3000) grism. These filters are located in two filter wheels: Filter Wheel #1 contains the J-low, J, H, and K_s filters, and Filter Wheel #2 contains the JH, HK, and Y filters, as well as a blank for dark frames. We also have two narrow band filters that will be installed at a later time. Further details can be found on the optomechanical diagrams.

The net system throughput curves (plots and data) for each filter (without the grisms) are linked from the table below. The net system throughput includes the transmission properties of the FLAMINGOS-2 optical train, including its window, its 9 lenses, and the reflectivity properties of its two flat mirrors. It does not include the effects of the atmosphere, the telescope, or the detector. Values for the centroid wavelength and equivalent width (EW) of the filter bandpass are given. The "cut-on" and "cut-off" wavelengths listed in the table are the wavelengths where the net transmission is higher than or equal to 80% or 50% (respectively) of the maximum transmission value.

Filter name	Center λ [µm]	Filter Width [nm]	80% cut-on Wavelength [µm]	80% cut-off Wavelength [µm]	50% cut-on Wavelength [µm]	50% cut-off Wavelength [µm]	Transmission curves
Y_G0811	1.020	89.4	0.985	1.066	0.969	1.068	plot/data
J_G0802	1.255	151	1.178	1.328	1.175	1.333	plot/data
H_G0803	1.631	274	1.490	1.767	1.486	1.775	plot/data
Ks_G0804	2.157	318	1.997	2.313	1.991	2.320	plot/data
Jlow_G0801	1.122	132	1.056	1.189	1.048	1.192	plot/data
JH_G0809	1.390	720	1.163	1.774	0.970	1.805	plot/data
HK_G0806	1.871	1067	1.308	2.401	1.261	2.511	plot/data
F_G0812	1.056	TBD	TBD	TBD	TBD	TBD
F_G0813	1.063	TBD	TBD	TBD	TBD	TBD

 

Transmission curves for the filters only, based on lab measurements, are also available.