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.
Broad-band filters
| Filter | Wavelength (A) | Sensitivity | mag for 1 e-/s |
||||
|---|---|---|---|---|---|---|---|
| Name | Plot | List | Centre | Width | (mag) | (mag/pixel) | |
| U |  |
 |
3600 | 560 | 26.0 | 28.5 | 25.7 |
| B | |
|
4400 | 1080 | 27.6 | 30.1 | 28.4 |
| 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