LUCI User`s Manual Download

Transcript
32
Issue 1.3
LUCIFER User Manual
Table 12: LUCIFER’s imaging zero points (defined as 1 ADU/SEC).
Filter
ZP
err(ZP)
Br gam
FeII
H2
HeI
P beta
P gam
Y1
Y2
OH 1060
OH 1190
J low
J high
21.4
21.6
21.45
21.9
21.47
21.43
23.5
23.46
21.5
21.47
24.15
23.85
0.02
0.03
0.02
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
z
J
H
K
Ks
24.5
24.85
24.7
24.45
24.02
0.03
0.03
0.02
0.03
0.03
Table 13 presents some 3 sigma limiting magnitudes derived assuming a seeing of 0.800 , an airmass of
1.5 and 3mm of water vapor, using a DIT of 10 sec and NDIT=360, to obtain one hour on source
integration.
Table 13: Imaging limiting magnitude for a SNR=3 in one hour integration
6.5.2
Filter
Sky mag.
Limiting mag.
z
J
H
Ks
17.5
16.0
14.0
13.0
24.4
23.9
22.9
22.1
Spectroscopy
During clear nights, spectrophotometric standard stars have been observed with the 1000 wide slit,
with the N1.8 camera and all the gratings .
Figure 14 presents typical spectra obtained on spectrophotometric standard stars for all spectroscopic
modes. Two stars were used:
FS6: z=13.06, J=13.271, H=13.321, K=13.404 (UKIRT magnitudes)
FS29: z = 12.98, J=13.215, H=13.255, K=13.33 (UKIRT magnitudes)
In z band, one is readout noise dominated, in J band depending on the water vapor in the atmosphere
one goes from readout noise dominated to sky background dominated. For H & K, spectra are sky
background dominated irrespective of the grating used.
Recommended DITs and NDITs
To avoid unnecessarily long calibrations in the morning, it is recommended to use one of the following