XMM-Newton Data Files Handbook

4.1.6.5 RGS Offset Files

An RGS offset (*R[1,2]*OFX.FIT) file is generated for each RGS camera. Each file consists of 18 images, $171\times 128$ pixels in size, corresponding to the averaged diagnostic images for each CCD and readout node, accumulated during three neighbour orbits. The naming convention for the extension is: CCDn_offset_[cd], where n indicates the CCD number, and [cd] the readout node.