2. Observations and data analysis
First observations of the Antennae with coarser resolution were obtained during the Performance Verification phase (Vigroux et al. 1996). The new ISOCAM results presented in this paper consist of a large raster map obtained with the LW3 (12-17 µm) filter using pixel field of view, with a full width at half max of the observed point spread function of . Full CVF scans were also made from 5.5 µm to 16.5 µm using the smallest possible increment, 0.1 µm step and pixel field of view (Vigroux et al. 1996).
The data analysis was performed using the CAM Interactive Analysis (CIA) 1 Software. For the raster map, dark subtraction was performed using a model of the secular evolution of ISOCAM's dark current (Biviano et al., 1997). Removal of cosmic ray induced spikes was performed using a multi-resolution median filtering technique (Stark et al. 1996). The data cube was then corrected for the memory effect of the LW detector using the inversion algorithm described in Abergel et al. (1996). As the raster was rather large, 5 5 pointings, the flat-field was built from the median off the sky positions of the galaxies.
© European Southern Observatory (ESO) 1998
Online publication: April 15, 1998