NIRCam Design Features
The parameters presented here are the result of the design studies leading up to NIRCam's Critical Desisgn Review in May, 2006. Small changes may still occur as the result of manufacturing necessities.
The key design features are:
- Nyquist-sampled imaging at 2 and 4 microns -- short wavelength sampling is 0.0317"/pixel and long wavelength sampling is 0.0648"/pixel
- 2.2'x4.4' FOV for one wavelength provided by two identical imaging modules, two wavelengths observable simultaneously via dichroics
- Wavelength coverage from 0.6 to 5 microns
- Selection of broad, intermediate, and narrow band filters (see chart below)
- Choice of pupil positions for imaging, coronagraphy or wavefront sensing
- All NIRCam modules have coronagraphic spots in the telescope focal plane. The pupil wheels include coronagraphic masks.
NIRCam will have the sensitivity to detect first light sources and a whole lot more as shown in the listing of sensitivities by filter. Note that these values are for point sources observed against 1.2 times the minimum zodaical background.
NIRCam will use 2Kx2K HgCdTe focal planes from Rockwell Science Center.
Correspondence Between Filters and Common Solid State Features
|
Filter |
Required Sensitivity:10-s in 10000 sec |
|
F070W |
20.9 |
|
F090W |
14.3 |
|
F115W |
11.8 |
|
F150W |
11.2 |
|
F200W |
10.4 |
|
F277W |
12.3 |
|
F356W |
13.8 |
|
F444W |
24.5 |
|
F140M |
28.1 |
|
F162M |
26.6 |
|
F182M |
25.5 |
|
F210M |
25.7 |
|
F250M |
38.1 |
|
F300M |
26.8 |
|
F335M |
28.0 |
|
F360M |
29.7 |
|
F410M |
36.7 |
|
F430M |
71.5 |
|
F460M |
55.7 |
|
F480M |
72.6 |
|
F164N |
268 |
|
F187N |
267 |
|
F212N |
265 |
|
F225N |
232 |
|
F323N |
240 |
|
F405N |
260 |
|
F418N |
271 |
|
F466N |
334 |
|
F470N |
341 |
| Name | Center | lambda 1 | lambda 2 | Bandpass | Location | Transmission | Use |
| F070W | 0.7000 | 0.6125 | 0.7875 |
0.1750 |
SW-Filt | 0.85 | General purpose |
| F090W | 0.9000 | 0.7875 | 1.0125 |
0.2250 |
SW-Filt | 0.85 | General purpose |
| F115W | 1.1500 | 1.0063 | 1.2938 |
0.2875 |
SW-Filt | 0.85 | General purpose |
| F150W | 1.5000 | 1.3125 | 1.6875 |
0.3750 |
SW-Filt | 0.85 | General purpose |
| F150W2 | 1.5000 | 1.0000 | 2.0000 |
1.0000 |
SW-Filt | No NIRCam Req | DHS Blocking |
| F200W | 2.0000 | 1.7500 | 2.2500 |
0.5000 |
SW-Filt | 0.85 | General purpose |
| F277W | 2.7700 | 2.4238 | 3.1163 |
0.6925 |
LW-Filt | 0.85 | General purpose |
| F322W2 | 3.2200 | 2.4150 | 4.0250 | 1.6100 | LW-Filt | 0.85 | Background Min. |
| F356W | 3.5600 | 3.1150 | 4.0050 |
0.8900 |
LW-Filt | 0.85 | General purpose |
| F444W | 4.4400 | 3.8850 | 4.9950 |
1.1100 |
LW-Filt | 0.85 | General purpose |
| F140M | 1.4000 | 1.3300 | 1.4700 |
0.1400 |
SW-Filt | 0.7 | cool stars, steam |
| F162M | 1.6200 | 1.5500 | 1.7010 |
0.1510 |
SW-Pup | 0.7 | cool stars, off-band for steam |
| F182M | 1.8200 | 1.7290 | 1.9500 |
0.2210 |
SW-Filt | 0.7 | cool stars, steam |
| F210M | 2.1000 | 1.9950 | 2.2050 |
0.2100 |
SW-Filt | 0.7 | methane |
| F250M | 2.5000 | 2.4167 | 2.5833 |
0.1667 |
LW-Filt | 0.7 | methane |
| F300M | 3.0000 | 2.8500 | 3.1500 |
0.3000 |
LW-Filt | 0.7 | water ice |
| F335M | 3.3500 | 3.1825 | 3.5175 | 0.3350 | LW-Filt | 0.7 | PAH |
| F360M | 3.6000 | 3.4200 | 3.7800 | 0.3600 | LW-Filt | 0.7 | Brown dwarfs,planets |
| F410M | 4.1000 | 3.8950 | 4.3050 |
0.4100 |
LW-Filt | 0.7 | Brown dwarfs,planets |
| F430M | 4.3000 | 4.2000 | 4.4000 |
0.2000 |
LW-Filt | 0.7 | carbon dioxide |
| F460M | 4.6000 | 4.5000 | 4.7000 |
0.2000 |
LW-Filt | 0.7 | CO |
| F480M | 4.8000 | 4.6000 | 5.0000 |
0.4000 |
LW-Filt | 0.7 | Brown dwarfs,planets |
| F164N | 1.6440 | 1.6358 | 1.6522 | 0.0164 | SW-Pup | 0.6 | [FeII] |
| F187N | 1.8756 | 1.8662 | 1.8850 |
0.0188 |
SW-Filt | 0.6 | P-alpha |
| F212N | 2.1218 | 2.1112 | 2.1324 |
0.0212 |
SW-Filt | 0.6 | Molecular hydrogen |
| F225N | 2.2477 | 2.2365 | 2.2589 |
0.0225 |
SW-Pup | 0.6 | Molecular hydrogen |
| F323N | 3.2350 | 3.2188 | 3.2512 |
0.0324 |
LW-Pup | 0.6 | Molecular hydrogen |
| F405N | 4.0523 | 4.0320 | 4.0725 |
0.0405 |
LW-Pup | 0.6 | Br-alpha |
| F418N | 4.1813 | 4.1604 | 4.2022 |
0.0418 |
LW-Pup | 0.6 | Molecular hydrogen |
| F466N | 4.6560 | 4.6327 |
4.6793 |
0.0466 |
LW-Pup | 0.6 | CO |
| F470N | 4.7050 | 4.6815 | 4.7285 | 0.0471 | LW-Pup | 0.6 | Molecular hydrogen |