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 sensitivities are per pixel.

Broad-band filters

Filter
Sensitivity

mag for
1 e-/s

Name L_cen(A)
Width(A)
(mag) (mag/pixel)
U 3600
560
25.8 28.7 25.7
B 4400
1080 27.4 30.3 28.4
V 5500
1000
27.0 29.9 28.3
Rc 6600
1170 26.6 29.5 28.2
Ic 8050

1460

26.0 28.9 27.9

Narrow-band filters

Filter Sensitivity

uJy for
1e/s

Name
L_cen(A)
Width(A)
(uJy)
(erg/s/cm^2)
(uJy/pixel (erg/s/cm^2/pix)
N373 3737

58

0.32 4.0E-17
0.024 3.0E-18
0.92
N386 3865
110
0.22 4.9E-17
0.017 3.8E-18
0.41
N487 4882
53
0.23 1.5E-17
0.018 1.2E-18
0.43
N502

5025

60

0.22 1.6E-17
0.017 1.2E-18
0.36
N512

5121

60
0.26 1.8E-17
0.020 1.4E-18
0.36
N642 6428

127

0.22 2.0E-17
0.017 1.6E-18
0.16
N658 6588

73

0.31 1.6E-17
0.024 1.2E-18
0.30
N670 6709

85

0.27 1.5E-17
0.021 1.2E-18
0.24

Conversion from Jy to flux System
To convert from uJy to an emission line flux, use the following formula:

lineflux.gif

For example, the point source emission line sensitivity of the N487filter is (3e-14 x 0.23 x 53)/48822 =1.53e-20 W/m2

1 Jy = 10^-23 erg sec^-1 cm^-2 Hz^-1
AB magnitude System
This magnitude system is defined such that, when monochromatic flux f is measured in erg sec^-1 cm^-2 Hz^-1,
m(AB) = -2.5 log(f) - 48.60
where the value of the constant is selected to define m(AB)=V for a flat-spectrum source. In this system, an object with constant flux per unit frequency interval has zero color.

References:

Conversion from AB magnitudes to Johnson+ magnitudes:
The following formulae convert between the AB magnitude systems and those based on Alpha Lyra:

B = B(AB) + 0.163 (+/- 0.004)
V = V(AB) + 0.044 (+/- 0.004)
Rc = Rc(AB) +-0.117 (+/- 0.006)
Ic = Ic(AB) +-0.342 (+/- 0.008)
Source: Frei & Gunn 1995
The number of photons incident through Standard Johnson-Cousine system at the top of the atmosphere
Band lambda_c dlambda/lambda Flux at m=0 Flux at m=0

um
Jy erg-1 s-1 cm-2 A-1
U 0.36 0.15 1810 4.19e-9
B 0.44 0.22 4260 6.60e-9
V 0.55 0.16 3640 3.61e-9
Rc 0.64 0.23 3080 2.26e-9
Ic 0.79 0.19 2550 1.23e-9

Reference: Bessel  (1979)
1 Jy = 1.51e7 photons sec^-1 m^-2 (dlambda/lambda)^-1