Zero Point for imaging and spectroscopy 

 

 
 
 

ZERO POINTS FOR IMAGING
ZERO POINTS FOR SPECTROSCOPY

ZERO POINTS FOR IMAGING
 

The next table shows the results for zero points for J,H,K filters and the three different optics for some standard stars:
 
Standard
Optic
Mag
it(s)
ZC
ZP
fs17
Wide field
12.27(K)
8
1.36159*109
22.83
fs21
Wide field
13.13(K)
10
1.32757*109
22.81
fs17
Wide field
12.68(J)
8
2.14769*109
23.33
fs21
Wide field
12.95(J)
25
1.93411*109
23.21
fs17
Wide field
12.34(H)
8
1.98384*109
23.24
fs21
Wide field
13.03(H)
15
1.85639*109
23.17
fs17
High Res
12.27(K)
16
1.44143*109
22.90
fs21
High Res
13.13(K)
15
1.42633*109
22.89
fs17
High Res
12.68(J)
15
2.05719*109
23.28
fs21
High Res
12.95(J)
40
1.94997*109
23.22
fs17
High Res
12.34(H)
15
1.90479*109
23.20
fs21
High Res
13.03(H)
30
1.79974*109
23.14
fs23
Very High Res
12.27(K)
7
1.46155*109
22.91
fs21
Very High Res
13.13(K)
15
1.48599*109
22.93
fs23
Very High Res
12.99(J)
25
1.98059*109
23.24
fs21
Very High Res
12.95(J)
60
1.84851*109
23.16
fs23
Very High Res
12.45(H)
25
1.88827*109
23.19
fs21
Very High Res
13.05(H)
45
1.83286*109
23.16

And these are the averages for all the optics and three bands:
 
Band
Optic
Zero Point
K
Wide Field
22.82±0.01
K
High Res
22.89±0.01
K
Very High Res
22.92±0.01
H
Wide Field
23.20±0.04
H
High Res
23.17±0.03
H
Very High Res
23.17±0.02
J
Wide Field
23.27±0.06
J
High Res
23.25±0.03
J
Very High Res
23.20±0.04

In the next figure, it's plotted exposure time (in sec) versus magnitude for imaging mode and  SNR=5
 
 
 
 

ZERO POINT FOR SPECTROSCOPY.

These are the data taken durin Jul 01 for spectroscopy 3 bands, grism3 and high resolution optic:
 
 
Band Zero Point Ext. Coef
K 21.93±0.25 0.1077
H 21.9±0.3 0.2538
J 21.4±0.6 0.1612

Here you can see the results of the last run for spectroscopy  in Jul 99.