OMEGA CASS - Technical Characteristics

Omega-Cass
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Array Type:
Rockwell 1024 x 1024 pixel HAWAII array,
(HgCdTe detector + Si MOSFET non-destructive readout)
 

Wavelength range:
1.0 µm - 2.5 µm
 

Telescopes:
The camera can be mounted on the Calar Alto 2.2 m or 3.5 m telescope
 

Pixel scale:
3.5 m - f/10  ~ 0.3 "/pixel 
~ 0.2 "/pixel 
~ 0.1 "/pixel 
3.5 m - with ALFA 
             f/25 		 ~ 0.12 "/pixel 
~ 0.08 "/pixel 
~ 0.04 "/pixel 
2.2 m - f/8  ~ 0.6 "/pixel 
~ 0.4 "/pixel 
~ 0.2 "/pixel 

Sensitivity:

for the 0.3 arcsec/pixel scale with 1 arcsec seeing
Filter 
Mag.
FS30 
Counts for
1 min
Counts for 
Zero Mag. *1/sec
Signal/Noise
limiting maginitude
3sigma* (1 min Obj. + 1min Sky)
J 
11.923 
1.44 *106
1.4106 * 109
2781 
19.4 
H 
11.979 
1.55 *106
1.5987* 109
2508 
19.4 
K 
12.015 
1.20 *106
1.2795 * 109
1139 
18.5 
* 3 sigma: integral flux of 3 by 3 pixel equals 3 times the noise
 

Filter options:

all numbers at 77 Kelvin
Filter
cut on 
/ µm
cut off
/ µm
Tpeak
/ %
Thickness
/mm
Comment
Status
J 
1.130
1.420 
80 
- 
- 
in 
H 
1.493 
1.798 
80 
- 
- 
in 
K 
2.008 
2.427 
81 
- 
- 
in 
Ks
2.002 
2.390 
- 
- 
- 
- 
K'
1.9438 
2.2919 
95 
- 
also called KM
in 
JH
0.9957
1.8677
95 
-
for spectroscopy
in
HK
1.484
2.409
86 
-
for spectroscopy
in
S2 
1.400 
1.850 
- 
- 
for spectroscopy 
- 
S3 
 1.838 
2.628 
75 
- 
for spectroscopy 
-
S1.91-2.13
1.915
2.130
95
-
for spectroscopy
in
H1
1491
1636
84
-
1. half of H
in
H2
1672
1878
90
-
2. half of H
in
K1 
1.9510 
2.2080 
91 
- 
1. half of K 
in 
K2 
 2.1495 
2.4127 
94 
- 
2. half of K 
in 
FNBilter
Central wavelength
/ µm
FWHM
/nm
Tpeak
/%
Thickness
/mm
Comment
Status
NB1.083 
1.0825 
8.6 
69 
- 
HeI 
in 
NB1.215 
1.215 
- 
- 
- 
cont. 
- 
NB1.257 
1.2565 
14.6 
71 
- 
[FeII]a 
in 
NB1.282 
1.2815 
14.3 
64 
- 
P beta 
in 
NB1.644 
1.6444
18.6
47 
- 
[ FeII]b 
 in 
NB1.710 
1.710 
- 
- 
- 
cont. 
- 
NB2.058 
2.058 
- 
- 
- 
HeIb 
- 
NB2.122 
2.1222 
22.2 
58 
- 
H2
 in 
NB2.144
2.143
22.8
80
-
cont.
in
NB2.166 
2.1670 
23.2 
55
- 
Br gama 
 in 
NB2.295 
2.295 
- 
- 
- 
cont. 
 - 

 

Spectroscopy

Available grisms - resolution numbers for the wide field optic
Grism No.
Resolution
 Status
1
 
 in - use at shared risk
2
 
 in - use at shared risk
3
 R = 1050 / 2 pixel
in
4
 R = 420 / 2 pixel
in

Available Slits
Slit
 Status 
50 µm 
in 
100 µm 
in
150  µm 
out
double slit
out
 153 µm / 204 µm 
in
255 µm / 339 µm
out

Peter Bizenberger
biz@mpia-hd.mpg.de
Tel. (+49) 6221 / 528-311