XMM-Newton Science Analysis System


ommosaic (ommosaic-2.11) [xmmsas_20230412_1735-21.0.0]

Description

ommosaic accepts an arbitrary number of sky-image files (ie those produced by omatt), or product unrotated-images (ie those produced by ommodmap) and produces a mosaiced image. The latter is not recommended for precision data analysis. The task can process a mixture of both low and high-resolution images. The output image file will contain three images:

1. The stacked image stored in the PRIMARY block of the FITS file.
2. An exposure image stored in the EXPOSURE block of the FITS file. It is constructed using the individual exposure times from each input file. The exposure times are corrected for the OM deadtime-fraction time before the image is created.

3. A 16-bit quality image stored in the QUALITY block of the FITS file.

The output image file (parameter mosaicedset) can be processed by omdetect. It should be noted that in omdetect's photometry stage, no coincidence-loss corrections will be applied (since the frame-time and deadtime-fraction parameters of the mosaiced images vary from one exposure to the other) and this means that the photometric accuracy will decrease with increasing source-brightness.