[ ESO ] La Silla

2p2-m Telescope

NOTE: As of April 1, 1998 IRAC1 is no longer offered at the ESO/MPI 2.2-m.

General Description
Instrument Performance
Array Characteristics
Filters and Objectives

General Desciption

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IRAC1 is ESO's 1 to 5 micron imager on the ESO 2.2m telescope. It is equipped with a 58x62 SBRC InSb array. Imaging can be done through the standard J, H, K and L' broadband filters, several narrow band filters and two Circular Variable Filters (CVFs). Imaging can be done through two different objectives with scales of 0.45 and 0.80 arc seconds per pixel.


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IRAC1 Users Manual
IRAC1 Technical Reports
Bad Pixel Map

Instrument Performance

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FilterZero PointTypical Backgrounds (Magnitudes/sq. arc-sec.)
J20.2015.0 - 16.3
H 19.7212.8 - 14.0
K 19.0711.2 - 12.6
L' 17.792.0 - 2.9
MN1 15.14-0.5 - 0.6
PAH Reference 18.18-
PAH 16.20 -
CVF 3.3 microns14.41 -

The Zero-Points are a function of the lens used (lens S3 in this case), the cleanliness of the mirror and the humidity.

Array Characteristics

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Detector MaterialInSb
Pixel Size76 microns
Number of Elements58x62 (3596)
Quantum Efficiency> 80%
Well Depth1,000,000 electrons
Dark Current (Soild Nitrogen Cooling - 44K)18000 electrons/sec
Dark Current (Liquid Helium Cooling - 13K) 850 electrons/sec
Read Out Noise (Double Correlated Read)500 electrons
Gain50 electrons/ADU

Filters and Objectives

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Filter (microns)Delta (microns)
H 1.650.30
K 2.20.40
PAH 3.30.16
PAH Reference 3.30.8
L' 3.750.7
NB L' 3.70.1
NB M1 4.70.17
NB M2 4.70.1
CVF11.5 - 2.6Resolution = 80
CVF22.6 - 4.5Resolution = 80

Imaging through broad band M is not possible. The sky flux is too high.
To get the ascii file of the transmission curve, click on the wavelength.

LensScale (arc-seconds per pixel)Field of View (arc-seconds)
L40.4526 x 28
S30.846 x 49

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