3C 273 the brightest and first quasar ever to be discovered
As part of the joint calibrations with CHANDRA and other observatories, the XMM-Newton
operations were carried out with slightly different pointing directions for the target 3C273.
This was designed to see how the detected X-ray flux changes with position within the
telescope field of view. These details were vital for the RGS spectrometer calibration,
as a slight position change can masquerade as an unexpected change in the measured
The black strips are small gaps between neighbouring detectors in the camera, while the
slightly brighter tailing strips coming from the target are an artefact of data collection in this
detector when very
bright objects are observed.
Last Update: 1 September 2019