FOCAS filters and sensitivities
All sensitivities on this page are 5-sigma in 1 hour of on-source
integration. Point source sensitivities assume 0.5'' seeing, while
surface brightness sensitivies are per pixel.
These numbers are preliminary and will be updated after the aluminization of the telescope in this summer and the engineering observation in October. (8/5/2010)
Broad-band filters
Filter |
Wavelength (A) |
Sensitivity |
mag for 1 e-/s |
Name | Plot | List |
Centre | Width |
(mag) | (mag/pixel) |
U |
|
|
3600 | 560 |
25.1 | 27.5 | 24.3 |
B |
|
|
4400 | 1080 |
27.5 | 30.1 | 28.0 |
V |
|
|
5500 | 1000 |
27.2 | 29.7 | 28.3 |
R |
|
|
6600 | 1170 |
26.8 | 29.3 | 28.2 |
I |
|
|
8050 | 1460 |
26.2 | 28.7 | 27.9 |
Narrow-band filters
These numbers are very preliminary.
Filter |
Wavelength (A) |
Sensitivity |
uJy for 1 e-/s |
Name | Plot | List |
Centre | Width |
(uJy) | (uJy/pixel) |
N373 |
|
|
3737 | 58 |
0.32 | 0.024 | 0.92 |
N386 |
|
|
3865 | 110 |
0.22 | 0.017 | 0.41 |
N487 |
|
|
4882 | 53 |
0.23 | 0.018 | 0.43 |
N502 |
|
|
5025 | 60 |
0.22 | 0.017 | 0.36 |
N512 |
|
|
5121 | 60 |
0.26 | 0.020 | 0.36 |
N642 |
|
|
6428 | 127 |
0.22 | 0.017 | 0.16 |
N658 |
|
|
6588 | 73 |
0.31 | 0.024 | 0.30 |
N670 |
|
|
6709 | 85 |
0.27 | 0.021 | 0.24 |
To convert from uJy to an emission line flux, use the following
formula:
For example, the point source emission line sensitivity of the N487
filter is (3e-14 x 0.23 x 53)/48822 =
1.53e-20 W/m2
|