NEW INFRARED CAMERA OF THE CAUCASIAN MOUNTAIN OBSERVATORY OF THE SAI MSU: DESIGN, MAIN PARAMETERS AND RST LIGHT

Abstract

The paper presents a prototype of an infrared photometer, made by the SAI of MSU on the base of a commercial infrared module Gavin-615A. The operating spectral range of the photometer is 3-5 µm. Studies of the photometer detector have shown that its parameters correspond to those declared by the manufacturer. Nonlinearity of the detector does not exceed ∼ 5% in the whole range of signals, coe cients of correction--function were determined. Additionally, we determined the readout noise RN = 1200 ± 210 e, conversioncoe cient GAIN = 520 ± 9 e/ADU, the BIAS = 960.5 ± 2.2 ADU, and dark current ≈ (9.3 ± 1.1) · 106-e /s,which consists of the sum of the detector dark current and radiation of the entrance window of the detector◦module. The value of dark current was measured at the window temperature of 6 C. Observations werestarted with the photometer at the 2.5-m telescope of the Causasian Mountain Observatory of MSU, the rst results are given in the paper. The unvignetted eld of view is 30'' . In the M band under good atmosphericconditions, an image quality is close to di raction limit. Images of a star with magnitude L = 7.96 and M = 6.78 were obtained with exposure of 20 seconds and a SNR∼10 ratio. It is shown that at high image quality with SNR=3 and exposure of 20 seconds it is possible to observe stars up to L ∼9m and M ∼8m . The main module of the photometer was also used for measurements of the sky background brightness.