STScI Logo

Hubble Space Telescope
COS Sensitivity

The table, below, compares the COS sensitivities to those of various STIS spectroscopic modes. The sensitivity depends upon the size of the spectral resolution element. Thus, for each mode, values for both the native resolution and binned resolution of the mode are provided to make these comparisons easier.

Mode λ/Δλ Binning Sλ
(1013 cnt s-1 resel-1) /
(erg cm-2 s-1 -1)
FUV Modes λ=1300 λ=1600


COS G130M
COS G160M
20,000
---
1.0
0.69
10,000
x2
2.0
1.4
2,500
x8
8.0
5.5
1,000
x20
20.
14.

STIS E140M
45,800
---
0.060
0.024
20,000
x2.3
0.14
0.055

STIS G140M
10,000
---
0.66
0.13
2,500
x4
2.6
0.52

COS G140L
2500
---
7.9
3.4
1,000
x2.5
20.
8.5
STIS G140L
1,000
---
12.6
3.0
NUV Modes =1800 =2300 =2800

COS G185M
COS G225M
COS G285M
20,000
---
0.43
1.1
1.5
10,000
x2
0.86
2.2
2.0
2,500
x8
3.4
8.8
12.
500
x40
17.
44.
60.

STIS E230M
30,000
---
0.062
0.30
0.36
20,000
x1.5
0.093
0.45
0.54

STIS G230M
10,000
---
0.20
0.94
1.0
2,500
x4
0.80
3.8
4.1

COS G230L
2,500
---
5.2
9.4
6.5
500
x5
26.
47.
32.
STIS G230L
500
---
8.8
32.
34.