Reduction and calibration of the MIPS 70 and 160 micron detectors

The Multiband Imaging Photometer for SIRTF (MIPS) will be one of the three instruments on the Space Infrared Telescope Facility (SIRTF). MIPS will produce images at 24 (128x128 pixels), 70 (32x32 pixels), and 160 (2x20 pixels) microns using Si:As (24 micron) and Ge:Ga (70 and 160 microns) based detectors. The reduction and calibration of the Ge:Ga images present special challenges due to the nature of the bulk photoconductive detectors. The observing strategy of MIPS has been specifically designed to make the reduction and calibration of the Ge:Ga images quite robust and is different from that employed by the Infrared Space Observatory (ISO). The observations are carried out in the fast not the slow time domain, i.e. sources do not stay on the same detector pixels between exposures (3, 4, or 10 seconds). In addition, all data are taken with a high degree of redundancy and a flat field is taken every 2 minutes. The repeatability of this flat field is better than 1%. Worst case source flux repeatability of 10-15% has also been demonstrated. The general outline of the Ge:Ga data reduction and calibration will be presented. This includes continuing characterization work in the laboratory with flight-like arrays which allows for the ongoing study of the behavior of Ge:Ga detectors

Reduction and calibration of the MIPS 70 and 160 micron detectors

The Multiband Imaging Photometer for SIRTF (MIPS) will be one of the three instruments on the Space Infrared Telescope Facility (SIRTF). MIPS will produce images at 24 (128x128 pixels), 70 (32x32 pixels), and 160 (2x20 pixels) microns using Si:As (24 micron) and Ge:Ga (70 and 160 microns) based detectors. The reduction and calibration of the Ge:Ga images present special challenges due to the nature of the bulk photoconductive detectors. The observing strategy of MIPS has been specifically designed to make the reduction and calibration of the Ge:Ga images quite robust and is different from that employed by the Infrared Space Observatory (ISO). The observations are carried out in the fast not the slow time domain, i.e. sources do not stay on the same detector pixels between exposures (3, 4, or 10 seconds). In addition, all data are taken with a high degree of redundancy and a flat field is taken every 2 minutes. The repeatability of this flat field is better than 1%. Worst case source flux repeatability of 10-15% has also been demonstrated. The general outline of the Ge:Ga data reduction and calibration will be presented. This includes continuing characterization work in the laboratory with flight-like arrays which allows for the ongoing study of the behavior of Ge:Ga detectors

The guaranteed time program with the multiband imaging photometer for SIRTF (MIPS)

The GTO program for the MIPS team is concentrated in two areas. First, the evolution of planetary debris disks will be traced from their formation at less than one million years old, to the stable disks around old stars. To do so, we will make maps from 3 to 200 microns (in collaboration with the IRAC team) of regions where young stars are forming, to characterize thoroughly the circumstellar excess emission. We will include clusters representing a range of density and age. We will also observe a selection of isolated evolved stars in the MIPS photometric bands at 24, 70, and 160 microns. These observations will catalog the debris disk excesses as a function of stellar mass, age, binarity, and the presence of planetary companions. Second, we will explore the evolution of infrared galaxies and AGNs. This program has two components. In collaboration with both the IRAC and IRS teams, we will map at moderate depth 9 square degrees of sky, and in collaboration with IRAC will make deeper maps of about 2 square degrees. The latter regions have been selected to overlap with very deep xray surveys to aid in identification of AGNs and study of their evolution. We will extend the results of the deep maps by observations of 18 massive galaxy clusters in the redshift range 0.2 < z < 0.4. These clusters will image about 50 square arcmin of the background Universe, raising sources out of the confusion that will limit the sensitivity of the other deep surveys