EOS P96 - f) Comparison of observations efficiency between airmasses and slit angles; g) Airmass constraints for observations

Doc:
Issue
Date
Page
VLT-MAN-ESO-14650-4942
P96
24.06.2015
31 of 161
ESO, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
f) Comparison of observations efficiency between airmasses and slit
angles
In the following table the efficiency is compared between airmass 1.51 and 1.10 (flux ratio
AM=1.51/AM=1.10).
arm
Slit angle
average
range
std
UVB
Parallactic
0.89
0.43-1.0
0.16
UVB
Parall+45
0.81
0.59-0.95
0.12
UVB
Parall+90
0.68
0.30-1.0
0.24
VIS
Parallactic
0.92
0.82-1.0
0.05
VIS
Parall+45
0.81
0.70-0.98
0.09
VIS
Parall+90
0.66
0.42-1.0
0.18
g) Airmass constraints for observations
To help in the process of observation preparation, below is a plot from VIMOS-MOS mode
showing the airmass limit depending of the target declination for an observation at ±2h of the
meridian.