Mid‐Infrared All‐Sky Survey with the Infrared Camera (IRC) on Board the ASTRO‐F Satellite

Abstract

An all-sky survey in two mid-infrared bands covering wavelengths from 6 to 12 and 14 to 26 μm, with a spatial resolution of ∼9''.4-10", will be performed with the Infrared Camera (IRC) on board the ASTRO-F infrared astronomical satellite. The expected detection limit for point sources is 80-130 mJy (5 σ). The all-sky survey will provide data with a detection limit and a spatial resolution an order of magnitude deeper and higher, respectively, than those of the Infrared Astronomical Satellite survey. The IRC is optimally designed for deep imaging in staring observations. It employs 256 × 256 Si:As IBC infrared focal plane arrays for the two mid-infrared channels. In order to make observations with the IRC during the scanning observations for the all-sky survey, a new method of operation for the arrays has been developed - "scan mode" operation. In the scan mode, only 256 pixels in a single row aligned in the cross-scan direction on the array are used as the scan detector, and they are sampled every 44 ms. Special care has been taken to stabilize the temperature of the array in scan mode, which enables the user to achieve a low readout noise, comparable to that in the imaging mode (20-30 e-). The accuracy of the position determination and the flux measurement for point sources is examined both in computer simulations and laboratory tests with the flight model camera and moving artificial point sources. In this paper we present the scan mode operation of the array, the results of the computer simulation and the laboratory performance test, and the expected performance of the IRC all-sky survey observations. © 2006. The Astronomical Society of the Pacific. All rights reserved.